September 1996
USER'S MANUAL FOR CORMIX:
A HYDRODYNAMIC MIXING ZONE MODEL
AND DECISION SUPPORT SYSTEM
FOR POLLUTANT DISCHARGES INTO SURFACE WATERS
by
Gerhard H. Jirka1, Robert L. Doneker2, and Steven W. Hinton3
DeFrees Hydraulics Laboratory
School of Civil and Environmental Engineering
Cornell University
Ithaca, New York 14853-3501
1now at: Institute for Hydromechanics, University of Karlsruhe
Karlsruhe, D-76131, Germany
2now at: Oregon Graduate Institute, PO Box 91000, Portland, OR 97291-1000
3 National Registry of Capacity Rights, West Peabody, MA 01960
Cooperative Agreement No. CX824847-01-0
Project Officer:
Dr. Hiranmay Biswas
OFFICE OF SCIENCE AND TECHNOLOGY
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, DC 20460
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Abstract
The Cornell Mixing Zone Expert System
(CORMIX, Version 3.0 or higher) is a software
system for the analysis, prediction, and design of
aqueous toxic or conventional pollutant
discharges into diverse water bodies. The major
emphasis is on the geometry and dilution
characteristics of the initial mixing zone -
including compliance with regulatory constraints-,
but the system also predicts the behavior of the
discharge plume at larger distances. The highly
user-interactive CORMIX system is implemented
on microcomputers (IBM-PC, or compatible), and
consists of three integrated subsystems:
—CORMIX1 for submerged single port
discharges,
—CORMIX2 for submerged multiport diffuser
discharges,
—CORMIX3 for buoyant surface discharges.
While CORMIX was originally developed
under the assumption of steady ambient
conditions, Version 3.0 also allows application to
highly unsteady environments, such as tidal
reversal conditions, in which transient
recirculation and pollutant build-up effects can
occur.
In addition, two post-processing models
are linked to the CORMIX system, but can also be
used independently. These are CORJET (the
Cornell Buoyant Jet Integral Model) for the
detailed analysis of the near-field behavior of
buoyant jets, and FFLOCATR (the Far-Field
Plume Locator) for the far-field delineation of
discharge plumes in non-uniform river or estuary
environments.
This user's manual gives a comprehensive
description of the CORMIX system; it provides
guidance for assembly and preparation of
required input data for the three subsystems; it
delineates ranges of applicability; it provides
guidance for interpretation and graphical display
of system output; and it illustrates practical
system application through several case studies.
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Acknowledgments
An earlier version of this user's manual
covering the three separate CORMIX subsystems
(Version 1.0) before they were integrated into a
comprehensive single system was developed
under support form the National Council of the
Paper Industry for Air and Stream Improvement
Inc. (NCASI) and was published as Technical
Bulletin No. 624 of NCASI (Jirka and Hinton,
1992). With the permission of NCASI, that user's
guide has up until recently also been distributed
by the USEPA-Center for Environmental
Assessment Modeling (CEAM), Athens, GA, as
part of the modeling support for CORMIX.
With the completion of CORMIX Version
3.0 and its many new program features, the
present revision and update of the user's manual
has become necessary. This work was
conducted at the DeFrees Hydraulics Laboratory,
Cornell University, as a Cooperative Agreement
with the United States Environmental Protection
Agency. The authors would like to extend their
appreciation to Dr. Hiranmay Biswas, Project
Officer, for his guidance of the project.
Additional support for the development,
testing and evaluation of CORMIX system
elements was provided by the State of Delaware
Department of Natural Resources (Mr. Rick
Greene, Project Officer) during 1991, by the
Austrian Verbundgesellschaft (Dr. Gerhard
Schiller, Project Officer) during 1991/92, and by
the State of Maryland Department of Natural
Resources (Dr. Paul Miller, Project Officer) during
1992 to 1995.
Cameron Wilkens, Electronics T echnician,
in the DeFrees Hydraulics Laboratory, generously
assisted with solutions for computer hardware
and software problems.
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Table of Contents
Abstract ii
Acknowledgments iii
Table of Contents iv
Glossary vii
Metric Conversion Factors
for Dimensions Used in CORMIX xii
I Introduction 1
II Background:
Mixing Processes and Mixing Zone Regulations 3
2.1 Hydrodynamic Mixing Processes 3
2.1.1 Near-Field Processes 3
2.1.2 Far-Field Processes 10
2.2 Mixing Zone Regulations 12
2.2.1 Legal Background 12
2.2.2 Mixing Zone Definitions 13
2.2.3 Special Mixing Zone Requirements for Toxic Substances 13
2.2.4 Current Permitting Practice on Mixing Zones 14
2.2.5 Relationship Between Actual Hvdrodvnamic Processes and Mixing Zone
Dimensions 15
III General Features of the CORMIX System 17
3.1 Overview 17
3.2 Capabilities and Major Assumptions of the Three Subsystems and the Post-Processor
Models 18
3.2.1 CORMIX Subsystems 18
3.2.2 Post-Processor Models CORJET and FFLOCATR 18
3.3 System Processing Sequence and Structure 19
3.4 CORMIX Data Input Features 19
3.5 Logic Elements of CORMIX: Flow Classification 21
3.6 Simulation Elements of CORMIX: Flow Prediction 21
3.7 CORMIX Output Features: Design Summary and Iterations 21
3.7.1 CORMIX Session Report 22
3.7.2 CORMIX1. 2 or 3 Prediction File 23
3.7.3 CMXGRAPH Plots 23
3.8 Post-Processor Models CORJET and FFLOCATR: Input and Output Features .... 23
3.9 Equipment Requirements, System Installation and Run Times 23
IV CORMIX Data Input 25
4.1 General Aspects of Interactive Data Input 25
4.2 Site/Case Identifier Data 25
4.3 Ambient Data 26
4.3.1 Bounded Cross-Section 28
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4.3.2 Unbounded Cross-section 31
4.3.3 Tidal Reversing Ambient Conditions 32
4.3.4 Ambient Density Specification 35
4.3.5 Wind speed 35
4.4. Discharge Data: CORMIX1 35
4.4.1 Discharge Geometry 35
4.4.2 Port Discharge Flow 37
4.5 Discharge Data: CORMIX2 37
4.5.1 Diffuser Geometry 37
4.5.2 Diffuser Discharge Flow 40
4.6 Discharge Data: CORMIX3 40
4.6.1 Discharge Geometry 40
4.6.2 Discharge Flow 43
4.7 Pollutant Data 43
4.8 Mixing Zone Data 44
4.9 Units of Measure 45
V CORMIX Output Features 47
5.1 Qualitative Output: Flow Descriptions 47
5.1.1 Descriptive Messages 47
5.1.2 Length Scale Computations 48
5.1.3 Description of Flow Classes 51
5.2 Quantitative Output: Numerical Flow Predictions 54
5.2.1 Summary Output in SUM 54
5.2.2 Detailed Prediction Output File/n'.CXn 54
5.3 Graphical Output: Display and Plotting of Plume Features Using CMXGRAPH .... 57
5.3.1 Access to CMXGRAPH 57
5.3.2 Use of CMXGRAPH 59
VI Post-Processor Models CORJET and FFLOCATR:
Input and Output Features 65
6.1 CORJET: The Cornell Buoyant Jet Integral Model 65
6.1.1 General Features 65
6.1.2 Access to CORJET 67
6.1.3 CORJET Input Data File 67
6.1.4 CORJET Output Features 70
6.2 FFLOCATR: The Far-Field Plume Locator 73
6.2.1 General Features 73
6.2.2 Access to FFLOCATR 75
6.2.3 FFLOCATR Cumulative Discharge Input Data File 76
6.2.4 FFLOCATR Output Features 77
VII Closure 79
7.1 Synopsis 79
7.2 System and Documentation Availability 79
7.3 User Support 80
Literature References 81
Appendix A
Flow Classification Diagrams for the Three CORMIX Subsystems 83
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Appendix B
C0RMIX1: Submerged Single Port Discharge in a Deep Reservoir 93
Appendix C
CORMIX1 and 2: Submerged Single Port Discharge
and Multiport Diffuser in a Shallow River 107
Appendix D
CORMIX3: Buoyant Surface Discharge In An Estuary 125
Appendix E
Two Applications of CORJET 141
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Glossary
Actual Water Depth (HP) - the actual water depth at the submerged discharge location. It is also called
local water depth. For surface discharges it is the water depth at the channel entry location.
Alignment Angle (GAMIWV) - the angle measured counterclockwise from the ambient current direction
to the diffuser axis.
Allocated Impact Zone - see mixing zone.
Alternating Diffuser - a multi-port diffuser where the ports do not point in a nearly single horizontal
direction.
Ambient Conditions - the geometric and dynamic characteristics of a receiving water body that impact
mixing zone processes. These include plan shape, vertical cross sections, bathymetry, ambient
velocity, and density distribution.
Ambient Currents - A velocity field within the receiving water which tends to deflect a buoyant jet into
the current direction.
Ambient Discharge (QA) - the volumetric flow rate of the receiving water body.
Average Diameter (DPI - the average diameter of the discharge ports or nozzles for a multi-port diffuser.
Average Depth (HA1 - the average depth of the receiving water body determined from the equivalent
cross sectional area during schematization.
Bottom Slope (SLOPEI - the slope of the bottom that extends from a surface discharge into the
receiving water body.
Buoyant Jet - a discharge where turbulent mixing is caused by a combination of initial momentum flux
and buoyancy flux. It is also called a forced plume.
Buoyant Spreading Processes - far-field mixing processes which arise due to the buoyant forces caused
by the density difference between the mixed flow and the ambient receiving water.
Buoyant Surface Discharge - the release of a positively or neutrally buoyant effluent into a receiving
water through a canal, channel, or near-surface pipe.
Coanda Attachment - a dynamic interaction between the effluent plume and the water bottom that
results from the entrainment demand of the effluent jet itself and is due to low pressure effects.
Cumulative Discharge - refers to the volumetric flow rate which occurs between the bank/shoreline and
a given position within the water body.
Cumulative Discharge Method - an approach for representing transverse plume mixing in river or
estuary flow by describing the plume centerline as being fixed on a line of constant cumulative discharge
and by relating the plume width in terms of a cumulative discharge increment
Darcv-Weisbach Friction Factor - a measure of the roughness characteristics in a channel.
Deep Conditions - see near-field stability.
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Density Stratification - the presence of a vertical density profile within the receiving water.
Diffuser Length (LD1 - The distance between the first and last port of a multi-port diffuser line. See
diffuser line.
Diffuser Line - a hypothetical line between the first and last ports of a multi-port diffuser.
Discharge Velocity CUP') - the average velocity of the effluent being discharged from the outfall structure.
Discharge from Shore (DISTB1 - the average distance between the outfall location (or diffuser mid-
point) and the shoreline. It is also specified as a cumulative ambient discharge divided by the product
UA times HA.
Distance from Shore (YB1. YB21 - the distance from the shore line to the first and last ports of a multi-
port diffuser.
Discharge Flow Rate (Q01 - the volumetric flow rate from the discharge structure.
Discharge Channel Width (B01 - the average width of a surface discharging channel.
Discharge Channel Depth (HOI - the average depth of a surface discharging channel.
Discharge Conditions - the geometric and flux characteristics of an outfall installation that effect mixing
processes. These include port area, elevation above the bottom and orientation, effluent discharge flow
rate, momentum flux, and buoyancy flux.
Far-field - the region of the receiving water where buoyant spreading motions and passive diffusion
control the trajectory and dilution of the effluent discharge plume.
Far-field Processes - physical mixing mechanisms that are dominated by the ambient receiving water
conditions, particularly ambient current velocity and density differences between the mixed flow and the
ambient receiving water.
FAST-CORMIX - a version of CORMIX data entry with short questions and without help sections; can
be chosen in main menu; for advanced users.
Flow Classification - the process of identifying the most appropriate generic qualitative description of
the discharge flow undergoing analysis. This is accomplished by examining known relationships
between flow patterns and certain calculated physical parameters.
Flux Characteristics - the properties of effluent discharge flow rate, momentum flux and buoyancy flux
for the effluent discharge.
Forced Plume - see buoyant jet.
Generic Flow Class - a qualitative description of a discharge flow situation that is based on known
relationships between flow patterns and certain physical parameters.
Height of Port (HOI - the average distance between the bottom and the average nozzle centerline.
High Water Slack (HWS1 - the time of tidal reversal nearest to MHW
Horizontal Angle (SIGMA1 - the angle measured counterclockwise from the ambient current direction
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to the plane projection of the port center line.
Hvdrodvnamic Mixing Processes - the physical processes that determine the fate and distribution of
effluent once it is discharged.
Input Data Sequence - a group of questions from one of four topical areas.
Intermediate-field Affects - induced flows in shallow waters which extend beyond the strictly near-field
region of a multi-port diffuser.
Iteration Menu - the last menu (red panel) the user can choose after completion of a design case; allows
iteration with different ambient/discharge/regulatory conditions.
Jet - see pure jet.
Laterally Bounded - refers to a water body which is constrained on both sides by banks such as rivers,
streams, estuaries and other narrow water courses.
Laterally Unbounded - a water body which for practical purposes is constrained on at most one side.
This would include discharges into wide lakes, wide estuaries and coastal areas.
Legal Mixing Zone (LMZ1 - see regulatory mixing zone.
Length Scale - a dynamic measure of the relative influence of certain hydrodynamic processes on
effluent mixing.
Length Scale Analysis - an approach which uses calculated measures of the relative influence of certain
hydrodynamic processes to identify key aspects of a discharge flow so that a generic flow class can be
identified.
Local Water Depth (HD1 - see actual water depth.
Low Water Slack (LWS1 - the time of tidal reversal nearest to MLW
Main Menu - the first menu (red panel) the user can choose from when entering CORMIX.
Manning's n - a measure of the roughness characteristics in a channel.
Maximum Tidal Velocity (Uamaxl - the maximum velocity occurring within the tidal cycle
Mean Ambient Velocity (UA1 - the average velocity of the receiving water body's flow.
Mean High Water (MLW) - the highest water level (averaged over many tidal cycles) in estuarine or
coastal flows.
Mean Low Water (MLW) - the lowest water level (averaged over many tidal cycles) in estuarine or
coastal flows.
Merging - the physical interaction of the discharge plumes from adjacent ports of a multi-port diffuser.
Mixing Zone - an administrative construct which defines a limited area or volume of the receiving water
where the initial dilution of a discharge is allowed to occur. In practice, it may occur within the near-field
or far-field of a hydrodynamic mixing process and therefore depends on source, ambient, and regulatory
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constraints.
Mixing Zone Regulations - The administrative construct that intends to prevent any harmful impact of
a discharged effluent on the aquatic environment and its designated uses.
Momentum Jet - see pure jet.
Multi-port Diffuser - a structure with many closely spaced ports or nozzles that inject more than one
buoyant jet into the ambient receiving water body.
Near-field - the region of a receiving water where the initial jet characteristic of momentum flux,
buoyancy flux and outfall geometry influence the jet trajectory and mixing of an effluent discharge.
Near-Field Region (NFR1 - a term used in the CORMIX printout for describing the zone of strong initial
mixing where the so called near-field processes occur. It is the region of the receiving water where
outfall design conditions are most likely to have an impact on in-stream concentrations.
Near-field Stability - the amount of local recirculation and re-entrainment of already mixed water back
into the buoyant jet region. Stable discharge conditions are associated with weak momentum and deep
water and are also sometimes called deep water conditions. Unstable discharge conditions have
localized recirculation patterns and are also called shallow water conditions.
Negative Buovancv - the measure of the tendency of an effluent discharge to sink in a receiving water.
Non-buovant Jet - see pure jet.
Open Format - data input which does not require precise placement of numerical values in fixed fields
and which allows character strings to be entered in either upper or lower case letters.
Passive Ambient Diffusion Processes - far-field mixing processes which arise due to existing turbulence
in the ambient receiving water flow.
Plume - see buoyant jet.
Positive Buovancv - the measure of the tendency of an effluent discharge to rise in the receiving water.
Post-Processor - several options available within CORMIX (main menu or iteration menu) for additional
computation or data display, including a graphics package, a near-field buoyant jet model, and a far-field
plume delineator.
Pure Jet - a discharge where only the initial momentum flux in the form of a high velocity injection
causes turbulent mixing. It is also called momentum jet or non-buoyant jet.
Pure Plume - a discharge where only the initial buoyancy flux leads to local vertical accelerations which
then lead to turbulent mixing.
Pvcnocline - a horizontal layer in the receiving water where a rapid density change occurs.
Pvcnocline Height (HINT) - the average distance between the bottom and a horizontal layer in the
receiving water body where a rapid density change occurs.
Region Of Interest (ROh - a user defined region of the receiving water body where mixing conditions
are to be analyzed.
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Regulatory Mixing Zone (RMZ1 - the region of the receiving water where mixing zone regulations are
applied. It is sometimes referred to as the legal mixing zone.
Relative Orientation Angle (BETA1 - the angle measured either clockwise or counterclockwise from the
average plan projection of the port centerline to the nearest diffuser axis.
Schematization - the process of describing a receiving water body's actual geometry with a rectangular
cross section.
Shallow Water Conditions - see near-field stability.
Stable Discharge - see near-field stability.
Staged Diffuser - a multi-port diffuser where all ports point in one direction, generally following the
diffuser line.
Stagnant Conditions - the absence of ambient receiving water flow. A condition which rarely occurs in
actual receiving water bodies.
Submerged Multi-port Diffuser - an effluent discharge structure with more than one efflux opening that
is located substantially below the receiving water surface.
Submerged Single Port Discharge - an effluent discharge structure with a single efflux opening that is
located substantially below the receiving water surface.
Surface Buoyant Jets - positively or neutrally buoyant effluent discharges occurring horizontally at the
water surface from a latterly entering channel or pipe.
Surface Width (BS1 - the equivalent average surface width of the receiving water body determined from
the equivalent rectangular cross sectional area during schematization.
Tidal cvcle - the variation of ambient water depth and velocity as a function of time occurring due to tidal
(lunar and solar) influences.
Tidal period (PERIOD') - the duration of the tidal cycle (on average 12.4 hours).
Tidal reversal - the two instances in the tidal cycle when the ambient velocity reverses its direction.
Toxic Dilution Zone (JDZ) - the region of the receiving water where the concentration of a toxic chemical
may exceed the acute effects concentration.
Unidirectional Diffuser - a multi-port diffuser with all ports pointing to one side of the diffuser line and
all ports oriented more or less normally to the diffuser line.
Unstable Discharge - see near-field stability.
Vertical Angle (THETAI - the angle between the port centerline and the horizontal plane.
Wake Attachment - a dynamic interaction of the effluent plume with the bottom that is forced by the
receiving water crossflow.
Zone of Initial Dilution - a term sometimes used to describe the mixing zone for the discharge of
municipal wastewater into the coastal ocean, limited to the extent of near-field mixing processes.
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Metric Conversion Factors
for Dimensions Used in CORMIX
Length: 1 m = 3.281 ft
= 39.37 in
= 0.0006214 mile
Velocity: 1 m/s
Discharge: 1 m3/s
Density: 1000 kg/m3
Temperature: °C
= 3.281 ft/s (fps)
= 2.237 miles/hr (mph)
= 1.943 knots
= 35.31 ft3/s (cfs)
= 22.82 million-gal/day (mgd)
= 62.43 lb/ft3
= (°F - 32.0) * 0.5556
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I Introduction
The Cornell Mixing Zone Expert System
(CORMIX) is a software system for the analysis,
prediction, and design of aqueous toxic or
conventional pollutant discharges into diverse
water bodies. It was developed under several
cooperative funding agreements between U.S.
EPA and Cornell University during the period
1985-1995. It is a recommended analysis tool in
key guidance documents (1,2,3) on the permitting
of industrial, municipal, thermal, and other point
source discharges to receiving waters. Although
the system's major emphasis is on predicting the
geometry and dilution characteristics of the initial
mixing zone so that compliance with water quality
regulatory constraints may be judged, the system
also predicts the behavior of the discharge plume
at larger distances.
The highly user-interactive CORMIX
system is implemented on IBM-DOS compatible
microcomputers, utilizes a rule-based systems
approach to data input and processing, and
consists of three subsystems. These are: (a)
CORMIX1 for the analysis of submerged single
port discharges, (b) CORMIX2 for the analysis of
submerged multiport diffuser discharges and (c)
CORMIX3 for the analysis of buoyant surface
discharges. Without specialized training in
hydrodynamics, users can make detailed
predictions of mixing zone conditions, check
compliance with regulations and readily
investigate the performance of alternative outfall
designs. The basic CORMIX methodology relies
on the assumption of steady ambient conditions.
However, recent versions also contain special
routines for the application to highly unsteady
environments, such as tidal reversal conditions, in
which transient recirculation and pollutant build-up
effects can occur.
In addition, several post-processing
options are available. These are CORJET (the
Cornell Buoyant Jet Integral Model) for the
detailed analysis of the near-field behavior of
buoyant jets, FFLOCATR (the Far-Field Plume
Locator) for the far-field delineation of discharge
plumes in non-uniform river or estuary
environments, and CMXGRAPH, a graphics
package for plume plotting.
Several factors provided the original
impetus for system development including: (a) the
considerable complexity of mixing processes in
the aquatic environment, resulting from the great
diversity of discharge and site conditions and
requiring advanced knowledge in a specialized
field of hydrodynamics; (b) the failure of
previously existing models (e.g. the U.S. EPA
plume models (4) originally developed for
municipal discharges in deep coastal waters) to
adequately predict often routine discharge
situations, especially for more shallow inland
sites; (c) the issuance in 1985 by the U.S. EPA of
additional guidelines (1) for the permitting of toxic
aqueous discharges, placing yet another burden
on both applicants and regulators in delineating
special zones for the initial mixing of these
substances; and (d) the availability of new
computer methods, so-called expert systems, for
making accessible to the user, within a simple
personal computing environment, the expert's
knowledge and experience in dealing with
complex engineering problems.
Four separate publications (5,6,7,8)
describe the scientific basis for the CORMIX
system and demonstrate comparison and
validation with field and laboratory data. The
results of these works are summarized in the
peer-reviewed literature (9,10,11,12,13,14,15,
16,17). The CORMIX systems approach and its
performance relative to the earlier U.S. EPA
plume models in the context of estuarine
applications is also described in EPA's technical
guidance manual for performing waste load
allocations in estuaries (3).
EPA's established policy is to make the
CORMIX system freely available to all potential
users through its modeling software distribution
facility at the U.S. EPA Center for Environmental
Assessment Modeling (CEAM) in Athens,
Georgia. Some of the CORMIX subsystems have
been available to the industrial and regulatory
user communities since December 1989 when
distribution of CORMIX1 was commenced by
Cornell University for the purpose of identifying
subtle programming errors through application to
actual mixing zone analysis problems by a
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controlled users group. After this testing was
deemed complete, CEAM commenced the
distribution of CORMIX1 in November 1990. A
similar approach was used to introduce CORMIX2
which began CEAM distribution in October 1991.
In 1992, CORMIX1, CORMIX2, and CORMIX3
were integrated a single program and distributed
by USEPA-CEAM as CORMIX Version 2.1 as of
1993.
Additional development of the post-
processor modules, including plume graphics, the
jet-integral model, and the far-field locator, were
added to the system and distributed as CORMIX
Version 3.0 as of 1994.
This manual describes the operation of a
revised version, including a special routine for
unsteady tidal applications, denoted as CORMIX
Version 3.1 that has been distributed by Cornell
as of June 1995. A slightly updated Version 3.2
will be distributed by USEPA-CEAM as of
September 1996.
The objectives of this user's guide are as
follows: (a) to provide a comprehensive
description of the CORMIX system; (b) to provide
guidance for assembly and preparation of
required input data for all three subsystems as
well as the post-processor models; (c) to
delineate ranges of applicability of the
subsystems; (d) to provide guidance for the
interpretation and graphical display of system
output; and (e) to illustrate practical system
application through several case studies.
This manual is organized to meet the
informational needs of two distinctly different
groups of readers: 1) personnel in environmental
management positions desiring an overview of
the CORMIX systems capabilities, and 2)
technical staff needing assistance in actual
applications. Chapter II provides a summary of
the physical processes of effluent mixing, as well
as an overview of the regulatory background and
practice on mixing zone applications. The
general features of the CORMIX system are
explained in Chapter III including summaries of:
(a) predictive capabilities and limitations, (b)
overall system structure and method of
processing information, (c) user interaction, and
(d) individual computational elements. Detailed
guidance on the preparation and entry of input
data, as required by the three CORMIX
subsystems, is given in Chapter IV. Chapter V
provides a description of system output,
containing descriptive, quantitative, and graphical
information on the predicted effluent flow.
Chapter VI describes the background, input and
output features of the CORJET jet integral model
and the far-field plume locator program
FFLOCATR. The closing remarks in Chapter VII
contain information on system availability and
user support, and on possible future
developments and enhancements.
Appendices to this guide present four
case studies on the application of all three
CORMIX subsystems and its post-processor
models. These are adapted from actual
situations and illustrate the complete input
requirements and output capabilities of the
system. In addition, some of the assumptions on
data schematization, problem simplification, and
output interpretation, and construction graphical
displays are discussed in a context typical of
many mixing zone model applications.
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II Background:
Mixing Processes and Mixing Zone Regulations
When performing design work and
predictive studies on effluent discharge problems,
it is important to clearly distinguish between the
physical aspects of hydrodynamic mixing
processes that determine the effluent fate and
distribution, and the administrative construct of
mixing zone regulations that intend to prevent
any harmful impact of the effluent on the aquatic
environment and associated uses.
2.1 Hydrodynamic Mixing Processes
The mixing behavior of any wastewater
discharge is governed by the interplay of ambient
conditions in the receiving water body and by the
discharge characteristics.
The ambient conditions in the receiving
water body, be it stream, river, lake, reservoir,
estuary or coastal waters, are described by the
water body's geometric and dynamic
characteristics. Important geometric parameters
include plan shape, vertical cross-sections, and
bathymetry, especially in the discharge vicinity.
Dynamic characteristics are given by the velocity
and density distribution in the water body, again
primarily in the discharge vicinity. In many cases,
these conditions can be taken as steady-state
with little variation because the time scale for the
mixing processes is usually of the order of
minutes up to perhaps one hour. In some cases,
notably tidally influenced flows, the ambient
conditions can be highly transient and the
assumption of steady-state conditions may be
inappropriate. In this case, the effective dilution
of the discharge plume may be reduced relative to
that under steady state conditions.
The discharge conditions relate to the
geometric and flux characteristics of the
submerged outfall installation. For a single port
discharge the port diameter, its elevation above
the bottom and its orientation provide the
geometry; for multiport diffuser installations the
arrangement of the individual ports along the
diffuser line, the orientation of the diffuser line,
and construction details represent additional
geometric features; and for surface discharges
the cross-section and orientation of the flow
entering the ambient watercourse are important.
The flux characteristics are given by the effluent
discharge flow rate, by its momentum flux and by
its buoyancy flux. The buoyancy flux represents
the effect of the relative density difference
between the effluent discharge and ambient
conditions in combination with the gravitational
acceleration. It is a measure of the tendency for
the effluent flow to rise (i.e. positive buoyancy)
or to fall (i.e. negative buoyancy).
The hydrodynamics of an effluent
continuously discharging into a receiving water
body can be conceptualized as a mixing process
occurring in two separate regions. In the first
region, the initial jet characteristics of momentum
flux, buoyancy flux, and outfall geometry influence
the jet trajectory and mixing. This region will be
referred to as the "near-field", and encompasses
the buoyant jet flow and any surface, bottom or
terminal layer interaction. In this near-field region,
outfall designers can usually affect the initial
mixing characteristics through appropriate
manipulation of design variables.
As the turbulent plume travels further
away from the source, the source characteristics
become less important. Conditions existing in the
ambient environment will control trajectory and
dilution of the turbulent plume through buoyant
spreading motions and passive diffusion due to
ambient turbulence. This region will be referred
to here as the "far-field". It is stressed at this
point that the distinction between near-field and
far-field is made purely on hydrodynamic grounds.
It is unrelated to any regulatory mixing zone
definitions.
2.1.1 Near-Field Processes
Three important types of near-field
processes are submerged buoyant jet mixing,
boundary interactions and surface buoyant jet
mixing as described in the following paragraphs.
3
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Submerged Buoyant Jet Mixing: The effluent
flow from a submerged discharge port provides a
velocity discontinuity between the discharged fluid
and the ambient fluid causing an intense shearing
action. The shearing flow breaks rapidly down
into a turbulent motion. The width of the zone of
high turbulence intensity increases in the direction
of the flow by incorporating ("entraining") more of
the outside, less turbulent fluid into this zone. In
this manner, any internal concentrations (e.g. fluid
momentum or pollutants) of the discharge flow
become diluted by the entrainment of ambient
water. Inversely, one can speak of the fact that
both fluid momentum and pollutants become
gradually diffused into the ambient field.
The initial velocity discontinuity may arise
in different fashions. In a "pure jet" (also called
"momentum jet" or "non-buoyant jet"), the initial
momentum flux in the form of a high-velocity
injection causes the turbulent mixing. In a "pure
plume," the initial buoyancy flux leads to local
vertical accelerations which then lead to turbulent
mixing. In the general case of a "buoyant jet"
(also called a "forced plume"), a combination of
initial momentum flux and buoyancy flux is
responsible for turbulent mixing.
Thus, buoyant jets are characterized by a
narrow turbulent fluid zone in which vigorous
mixing takes place. Furthermore, depending on
discharge orientation and direction of buoyant
acceleration, curved trajectories are generally
established in a stagnant uniform-density
environment as illustrated in Figure 2.1a.
Buoyant jet mixing is further affected by
ambient currents and density stratification. The
role of ambient currents is to gradually deflect
the buoyant jet into the current direction as
illustrated in Figure 2.1b and thereby induce
additional mixing. The role of ambient density
stratification is to counteract the vertical
acceleration within the buoyant jet leading
ultimately to trapping of the flow at a certain level.
Figure 2.1c shows a typical buoyant jet shape at
the trapping or terminal level.
Finally, in case of multiport diffusers, the
individual round buoyant jets behave
independently until they interact, or merge, with
each other at a certain distance from the efflux
ports. After merging, a two-dimensional buoyant
jet plane is formed as illustrated in Figure 2.1d.
Such plane buoyant jets resulting from a multiport
diffuser discharge in deep water can be further
affected by ambient currents and by density
stratification as discussed in the preceding
paragraph.
Boundary Interaction Processes and Near-
Field Stability: Ambient water bodies always
have vertical boundaries. These include the
water surface and the bottom, but in addition,
"internal boundaries" may exist at pycnoclines.
Pycnoclines are layers of rapid density change.
Depending on the dynamic and geometric
characteristics of the discharge flow, a variety of
interaction phenomena can occur at such
boundaries, particularly where flow trapping may
occur.
In essence, boundary interaction
processes provide a transition between the
buoyant jet mixing process in the near-field, and
between buoyant spreading and passive diffusion
in the far-field. They can be gradual and mild, or
abrupt leading to vigorous transition and mixing
processes. They also can significantly influence
the stability of the effluent discharge conditions.
The assessment of near-field stability,
i.e. the distinction of stable or unstable conditions,
is a key aspect of effluent dilution analyses. It is
especially important for understanding the
behavior of the two-dimensional plumes resulting
from multiport diffusers, as shown by some
examples in Figure 2.2. "Stable discharge"
conditions, usually occurring for a combination of
strong buoyancy, weak momentum and deep
water, are often referred to as "deep water"
conditions (Figures 2.2a,c). "Unstable
discharge" conditions, on the other hand, may be
considered synonymous to "shallow water"
conditions (Figure 2.2b,d). Technical discussions
on discharge stability are presented elsewhere
(18,19).
A few important examples of boundary
interaction for a single round buoyant jet are
illustrated in Figure 2.3. If a buoyant jet is bent-
over by a cross-flow, it will gradually approach the
surface, bottom or terminal level and will undergo
a smooth transition with little additional mixing
4
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impingement point can take on one of the
following forms: (a) If the flow has sufficient
buoyancy it will ultimately form a stable layer at
the surface (Figure 2.3b). In the presence of
weak ambient flow this will lead to an upstream
intrusion against the ambient current, (b) If the
buoyancy of the effluent flow is weak or its
momentum very high, unstable recirculation
phenomena can occur in the discharge vicinity
(Figure 2.3c). This local recirculation leads to re-
entrainment of already mixed water back into the
buoyant jet region, (c) In the intermediate case, a
combination of localized vertical mixing and
upstream spreading may result (Figure 2.3d).
Another type of interaction process
concerns submerged buoyant jets discharging in
the vicinity of the water bottom into a stagnant or
flowing ambient. Two types of dynamic interaction
processes can occur that lead to rapid attachment
of the effluent plume to the water bottom as
illustrated in Figure 2.4. These are wake
attachment forced by the receiving water's
crossflow or Coanda attachment forced by the
entrainment demand of the effluent jet itself. The
latter is due to low pressure effects as the jet
periphery is close to the water bottom.
Port
Finally
plume-like
Initially
iet-like
a) Buoyant Jet in Stagnant
Uniform Ambient
Ambient
current
b) Buoyant Jet in Uniform
Ambient Cross-Current
Terminal
level
Density
current
c) Buoyant Jet in Stagnant
Stratified Ambient
Round
Plane
X Merging
Side View
Tap View
d) Jet Merging for Unidirectional
Multipart Diffuser Forming Plane
Buoyant Jet
Figure 2.1: Typical buoyant jet mixing flow patterns under different ambient conditions
5
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a) Deep Water, High Buoyancy,
Vertical: Stable Near-Field
c) Deep Water, High Buoyancy,
Near-Horizontal: Stable Near-Field
b) Shallow Water, Low Buoyancy, d) Shallow Water, Low Buoyancy,
Vertical: Unstable Near-Field Near-Horizontal: Unstable Near-Field
with Local Mixing and with Full Vertical Mixing
Restratification
Figure 2.2: Examples of near-field stability and instability conditions for submerged discharges in
limited water depth
6
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a) Gradual Surface Approach (Near-Horizontal) c) Surface Impingement with Full Vertical Mixing
in Shallow Water
Side View
Weak ambient ~
current
Density
current
Stagnation
point
Side View
b) Surface Impingement with Buoyant
Upstream Spreading
d) Surface Impingement with Local Vertical Mixing,
Buoyant Upstream Spreading and Restratification
Figure 2.3: Examples of boundary interactions for submerged jets in finite depth
7
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i) Free Deflected Jet/Plume ii) Wake Attachment of
in Cross-flow Jet/Plume
a) Wake Attachment
i) Free Jet
ii) Attached Jet
b) Coanda Attachment
Figure 2.4: Examples of wake (crossflow induced) attachment and Coanda attachment conditions for
jets discharging near boundaries
-------
Surface Buoyant Jet Mixing: Positively
buoyant jets discharged horizontally along the
water surface from a laterally entering channel or
pipe (Figure 2.5) bear some similarities to the
more classical submerged buoyant jet. For a
relatively short initial distance, the effluent
behaves like a momentum jet spreading both
laterally and vertically due to turbulent mixing.
After this stage, vertical entrainment becomes
inhibited due to buoyant damping of the turbulent
motions, and the jet experiences strong lateral
spreading. During stagnant ambient conditions,
ultimately a reasonably thin layer may be formed
at the surface of the receiving water; that layer
can undergo the transient buoyant spreading
motions depicted in Figure2.5a.
Plan View
////
[ Vertical
i entrainment
Plan View
7777777777777777,
/
. Recirculation
[ region v
^ ^^77777777777777777777777777777777^777777777
a) Buoyant Surface Jet in Stagnant Ambient
c) Shoreline-Attached Surface Jet in Strong
Ambient Crossflow
— Plan View
—— Plan View
V////V/V/V/V/V/,
b) Buoyant Surface Jet in Ambient Crossflow d) Upstream Intruding Plume in Weak Ambient
Crossflow
2.5: Typical buoyant surface jet mixing flow patterns under stagnant or flowing ambient conditions
9
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In the presence of ambient crossflow,
buoyant surface jets may exhibit any one of
following three types of flow features: They may
form a weakly deflected jet that does not interact
with the shoreline (Figure 2.5b). When the
crossflow is strong, they may attach to the
downstream boundary forming a shore-hugging
plume (Figure 2.5c). When a high discharge
buoyancy flux combines with a weak crossflow,
the buoyant spreading effects can be so strong
that an upstream intruding plume is formed that
also stays close to the shoreline (Figure 2.5d).
Intermediate-Field Effects for Multiport
Diffuser Discharges: Some multiport diffuser
installations induce flows in shallow water which
extend beyond the strict near-field region. The
resulting plumes are sometimes referred to as the
"intermediate-field" (18) because they interact
with the receiving water at distances that are
substantially greater than the water depth; the
order of magnitude of the water depth is typically
used to define the dimensions of the near-field
region. Intermediate fields may occur when a
multiport diffuser represents a large source of
momentum with a relatively weak buoyancy effect.
Such a diffuser will have an unstable near-field
with shallow water conditions. For certain diffuser
geometries (e.g. unidirectional & staged diffuser
types; see Section V) strong motions can be
induced in the shallow water environment in the
form of vertically mixed currents that laterally
entrain ambient water and may extend over long
distances before they re-stratify or dissipate their
momentum.
Another type of interaction process
concerns submerged buoyant jets discharging in
the vicinity of the water bottom into a stagnant or
flowing ambient. Two types of dynamic
interaction processes can occur that lead to rapid
attachment of the effluent plume to the water
bottom as illustrated in Figure 2.4. These are
wake attachment forced by the receiving water's
crossflow or Coanda attachment forced by the
entrainment demand of the effluent jet itself. The
latter is due to low pressure effects as the jet
periphery is close to the water bottom.
2.1.2 Far-Field Processes
Far-field mixing processes are
characterized by the longitudinal advection of the
mixed effluent by the ambient current velocity.
Buoyant Spreading Processes: These are
defined as the horizontally transverse spreading
of the mixed effluent flow while it is being
advected downstream by the ambient current.
Such spreading processes arise due to the
buoyant forces caused by the density difference
of the mixed flow relative to the ambient density.
They can be effective transport mechanisms that
can quickly spread a mixed effluent laterally over
large distances in the transverse direction,
particularly in cases of strong ambient
stratification. In this situation, effluent of
considerable vertical thickness at the terminal
level can collapse into a thin but very wide layer
unless this is prevented by lateral boundaries. If
the discharge is non-buoyant, or weakly buoyant,
and the ambient is unstratified, there is no
buoyant spreading region in the far-field, only a
passive diffusion region.
Depending on the type of near-field flow
and ambient stratification, several types of
buoyant spreading may occur. These include: (a)
spreading at the water surface, (b) spreading at
the bottom, (c) spreading at a sharp internal
interface (pycnocline) with a density jump, or (d)
spreading at the terminal level in continuously
stratified ambient fluid. As an example, the
definition diagram and structure of surface
buoyant spreading processes somewhat
downstream of the discharge in unstratified
crossflow is shown in Figure 2.6.
The laterally spreading flow behaves like
a density current and entrains some ambient fluid
in the "head region" of the current. During this
phase, the mixing rate is usually relatively small,
the layer thickness may decrease, and a
subsequent interaction with a shoreline or bank
can impact the spreading and mixing processes.
Passive Ambient Diffusion Processes: The
existing turbulence in the ambient environment
becomes the dominating mixing mechanism at
sufficiently large distances from the discharge
point. In general, the passively diffusing flow
grows in width and in thickness until it interacts
10
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The strength of the ambient diffusion
mechanism depends on a number of factors
relating mainly to the geometry of the ambient
shear flow and the amount of ambient
stratification. In the context of classical diffusion
theory (20), gradient diffusion processes in the
bounded flows of rivers or narrow estuaries can
be described by constant diffusivities in the
vertical and horizontal direction that depend on
Plan View
turbulent intensity and on channel depth or width
as the length scales. In contrast, wide
"unbounded" channels or open coastal areas are
characterized by plume size dependent
diffusivities leading to accelerating plume growth
described, for example, by the "4/3 law" of
diffusion. In the presence of a stable ambient
stratification, the vertical diffusive mixing is
generally strongly damped.
Front
U,
Initial
Condition
Figure 2.6: Buoyant spreading processes downstream of the near-field region (example of spreading
along the water surface)
11
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0 -
Turbulent
flow
•Initial Conditions
Side View
Possible Bottom Interaction
Figure 2.7: Passive ambient diffusion process with advection in the far-field
2.2 Mixing Zone Regulations
The discharge of waste water into a
water body can be considered from two vantage
points regarding its impact on ambient water
quality. On a larger scale, seen over the entire
receiving water body, care must be taken that
water quality conditions that protect designated
beneficial uses are achieved. This is the realm
of the general waste load allocation (WLA)
procedures and models.
On a local scale, or in the immediate
discharge vicinity, additional precautions must be
taken to insure that high initial pollutant
concentrations are minimized and constrained to
small zones, areas, or volumes. The generic
definition of these zones, commonly referred to
as "mixing zones", is embodied in federal water
quality regulations and often cited in the
regulations of permit granting authorities. As
stated previously, mixing zones are
administrative constructs that are independent of
hydrodynamic mixing processes.
2.2.1 Legal Background
The Clean Water Act of 1977 defines five
general categories of pollutants. These are: (a)
conventional, (b) nonconventional, (c) toxics, (d)
heat, and (e) dredge and fill spoil. The Act
distinguishes between new and existing sources
12
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for setting effluent standards. Pollutants
designated as "conventional" would be "generally
those pollutants that are naturally occurring,
biodegradable, oxygen demanding materials and
solids. In addition, compounds which are not
toxic and which are similar in characteristics to
naturally occurring, biodegradable substances are
to be designated as conventional pollutants for
the purposes of the provision." Examples of
conventional pollutants are: biochemical oxygen
demand (BOD), total suspended solids, and fecal
coliform bacteria. Pollutants designated as
"nonconventional" would be "those which are not
toxic or conventional", and some examples are:
chemical oxygen demand (COD), fluoride, and
ammonia. "Toxic" pollutants are those that cause
harmful effects, either acute or chronic, at very
low concentrations; examples of some designated
toxic substances are: nickel, chloroform, or
benzidine.
2.2.2 Mixing Zone Definitions
The mixing zone is defined as an
"allocated impact zone" where numeric water
quality criteria can be exceeded as long as
acutely toxic conditions are prevented. A mixing
zone can be thought of as a limited area or
volume where the initial dilution of a discharge
occurs (21). Water quality standards apply at the
boundary of the mixing zone, not within the mixing
zone itself. The U.S. EPA and its predecessor
agencies have published numerous documents
giving guidance for determining mixing zones.
Guidance published by U.S. EPA in the 1984
Water Quality Standards Handbook (21)
supersedes these sources.
In setting requirements for mixing zones,
U.S. EPA (22) requires that "the area or volume of
an individual zone or group of zones be limited to
an area or volume as small as practicable that will
not interfere with the designated uses or with the
established community of aquatic life in the
segment for which the uses are designated," and
the shape be "a simple configuration that is easy
to locate in the body of water and avoids
impingement on biologically important areas," and
"shore hugging plumes should be avoided."
The U.S. EPA rules for mixing zones
recognize the State has discretion whether or not
to adopt a mixing zone and to specify its
dimensions. The U.S. EPA allows the use of a
mixing zone in permit applications except where
one is prohibited in State regulations. A previous
review (5) of individual State mixing zone policies
(1,22) found that 48 out of 50 States make use of
a mixing zone in some form; the exceptions are
Arizona and Pennsylvania. State regulations
dealing with streams or rivers generally limit
mixing zone widths or cross-sectional areas, and
allow lengths to be determined on a case by case
basis.
In the case of lakes, estuaries and coastal
waters, some states specify the surface area that
can be affected by the discharge. The surface
area limitation usually applies to the underlying
water column and benthic area. In the absence of
specific mixing zone dimensions, the actual shape
and size is determined on a case-by-case basis.
Special mixing zone definitions have been
developed for the discharge of municipal
wastewater into the coastal ocean, as regulated
under Section 301(h) of the Clean Water Act (23).
Frequently, these same definitions are used also
for industrial and other discharges into coastal
waters or large lakes, resulting in a plurality of
terminology. For those discharges, the mixing
zone was labeled as the "zone of initial dilution"
in which rapid mixing of the waste stream (usually
the rising buoyant fresh water plume within the
ambient saline water) takes place. EPA requires
that the "zone of initial dilution" be a regularly
shaped area (e.g. circular or rectangular)
surrounding the discharge structure (e.g.
submerged pipe or diffuser line) that
encompasses the regions of high (exceeding
standards) pollutant concentrations under design
conditions (23). In practice, limiting boundaries
defined by dimensions equal to the water depth
measured horizontally from any point of the
discharge structure are accepted by the EPA
provided they do not violate other mixing zone
restrictions (23).
2.2.3 Special Mixing Zone Requirements for
Toxic Substances
The U.S. EPA maintains two water quality
criteria for the allowable concentration of toxic
substances: a criterion maximum concentration
13
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(CMC) to protect against acute or lethal effects;
and a criterion continuous concentration (CCC) to
protect against chronic effects (1). The CMC
value is greater than or equal to the CCC value
and is usually more restrictive. The CCC must be
met at the edge of the same regulatory mixing
zone specified for conventional and noncon-
ventional discharges.
Lethality to passing organisms within the
mixing zone can be prevented in one of four
ways:
The first alternative is to meet the CMC
criterion within the pipe itself.
The second alternative is to meet the
CMC within a short distance from the outfall. If
dilution of the toxic discharge in the ambient
environment is allowed, a toxic dilution zone
(TDZ), which is usually more restrictive than the
legal mixing zone for conventional and
nonconventional pollutants, may be used. The
revised 1991 Toxics TSD document (1)
recommends for new discharges a minimum exit
velocity of 3 meters per second (10 feet per
second) in order to provide sufficiently rapid
mixing that would minimize organism exposure
time to toxic material. The TSD does not set a
requirement in this regard, recognizing that the
restrictions listed in the following paragraph can in
many instances also be met by other designs,
especially if the ambient velocity is large.
As the third alternative, the outfall design
must meet the most restrictive of the following
geometric restrictions for a TDZ:
The CMC must be met within 10% of the
distance from the edge of the outfall
structure to the edge of the regulatory
mixing zone in any spatial direction.
The CMC must be met within a distance
of 50 times the discharge length scale in
any spatial direction. The discharge
length scale is defined as the square-root
of the cross-sectional area of any
discharge outlet. This restriction is
intended to ensure a dilution factor of at
least 10 within this distance under all
possible circumstances, including
situations of severe bottom interaction
and surface interaction.
The CMC must be met within a distance
of 5 times the local water depth in any
horizontal direction. The local water depth
is defined as the natural water depth
(existing prior to the installation of the
discharge outlet) prevailing under mixing
zone design condition (e.g. low flow for
rivers). This restriction will prevent
locating the discharge in very shallow
environments or very close to shore,
which would result in significant surface
and bottom concentrations (1).
A fourth alternative is to show that a
drifting organism would not be exposed more than
1-hour to average concentrations exceeding the
CMC.
2.2.4 Current Permitting Practice on Mixing
Zones
It is difficult to generalize the actual
practice in implementing the mixing zone
regulations, given the large number and diverse
types of jurisdictions and permit-granting
authorities involved. By and large, however,
current procedure falls into one of the following
approaches, or may involve a combination
thereof.
(i) The mixing zone is defined by some
numerical dimension, as discussed above. The
applicant must then demonstrate that the existing
or proposed discharge meets all applicable
standards for conventional pollutants or for the
CCC of toxic pollutants at the edge of the
specified mixing zone.
(ii) No numerical definition for a mixing
zone may apply. In this case a mixing zone
dimension may be proposed by the applicant. To
do so the applicant generally uses actual
concentration measurements for existing
discharges, dye dispersion tests or model
predictions to show at what plume distance, width,
or region, the applicable standard will be met.
The applicant may then use further ecological or
water use-oriented arguments to demonstrate that
14
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the size of that predicted region provides
reasonable protection. The permitting authority
may evaluate that proposal, or sometimes pursue
its own independent proposal for a mixing zone.
This approach resembles a negotiating process
with the objective of providing optimal protection
of the aquatic environment consistent with other
uses.
As regards the acute, or CMC, criterion for
toxic pollutants, the spatial restrictions embodied
in the Toxics TSD document (1) call for very
specific demonstrations of how the CMC criterion
is met at the edge of the "toxic dilution zone".
Again, field tests for existing discharges or
predictive models may be used.
2.2.5 Relationship Between Actual Hvdrodvnamic
Processes and Mixing Zone Dimensions
The spatial requirements in mixing zone
regulations are not always correlated with the
actual hydrodynamic processes of mixing. With
few exceptions, the toxic dilution criteria apply to
the near-field of most discharges since the TDZ
criteria (2) are spatially highly restrictive. The
regular mixing zone boundaries, however, may be
located in the near-field or the far-field of the
actual effluent discharge flow since they are
administratively determined by the permit-granting
authority. Thus, the analyst must have tools at his
disposal with the capability to address both the
near and far-field situations.
15
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&
16
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Ill General Features of the CORMIX System
This section provides a general
description of common features of CORMIX.
CORMIX Version 3.1 has three different
subsystem modules for diverse discharge
conditions. The subsystems are CORMIX1,
CORMIX2, and CORMIX3 for the analysis of
submerged single port, submerged multiport, and
buoyant surface outfall configurations,
respectively. Furthermore, two post-processor
models CORJET, a near-field jet integral model,
and FFLOCATR, a far-field plume locator in non-
uniform channels, are included. The following two
sections give a detailed guidance for developing
the required input data and for understanding
program output. Reference is made throughout
this document to CORMIX Version 3.1 dated June
1995 or Version 3.2 dated September 1996; other
versions may differ somewhat.
3.1 Overview
The CORMIX system represents a robust
and versatile computerized methodology for
predicting both the qualitative features (e.g. flow
classification) and the quantitative aspects (e.g.
dilution ratio, plume trajectory) of the
hydrodynamic mixing processes resulting from
different discharge configurations and in all types
of ambient water bodies, including small streams,
large rivers, lakes, reservoirs, estuaries, and
coastal waters. The methodology: (a) has been
extensively verified by the developers through
comparison of simulation results to available field
and laboratory data on mixing processes
(5,6,7,8), (b) has undergone independent peer
review in journal proceedings (9,10,11,12,13,
14,15,16,17) and (c) is equally applicable to a
wide range of problems from a simple single
submerged pipe discharge into a small stream
with rapid cross-sectional mixing to a complicated
multiport diffuser installation in a deeply stratified
coastal water.
System experience suggests that
CORMIX1 applies to better than 95% of
submerged single-port designs, CORMIX2 to
better than 80% of multiport diffusers, and
CORMIX3 to better than 90% of surface
discharges. Lack of applicability is usually given
by highly non-uniform ambient flow conditions that
are prone to locally recirculating flows. Other
non-applicable cases may arise to complicated
discharge geometries in which case CORMIX
advises the user not to proceed with the analysis.
Whenever the model is applicable extensive
comparison with available field and laboratory
data has shown that the CORMIX predictions on
dilutions and concentrations, with associated
plume geometries, are accurate to within ± 50 %
(standard deviation).
The methodology provides answers to
questions that typically arise during the
application of mixing zone regulations for both
conventional and toxic discharges. More
importantly, this is accomplished by utilizing the
customary approaches often used in evaluating
and implementing mixing zones, thereby providing
a common framework for both applicants and
regulatory personnel to arrive at a consensus
view of the available dilution and plume trajectory
for the site and effluent discharge characteristics.
The methodology also provides a way for
personnel with little or no training in
hydrodynamics to investigate improved design
solutions for aquatic discharge structures. To
limit misuse, the system contains limits of
applicability that prevent the simulation of
situations for which no safe predictive methodo-
logy exists, or for discharge geometries that are
undesirable from a hydrodynamic viewpoint.
Furthermore, warning labels, data screening
mechanisms, and alternative design
recommendations are furnished by the system.
The system is not fool proof, however, and final
results should always be examined for
reasonableness.
Finally, CORMIX is an educational tool
that intends to make the user more
knowledgeable and appreciative about effluent
discharge and mixing processes. The system is
not simply a black box that produces a final
numerical or graphical output, but contains an
interactive menu of user guidance, help options,
and explanatory material of the relevant physical
processes. These assist users in understanding
model predictions and exploring the sensitivity of
model predictions to assumptions.
17
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3.2 Capabilities and Major Assumptions of the
Three Subsystems and the Post-Processor
Models
3.2.1 CORMIX Subsystems
CORMIX1 predicts the geometry and
dilution characteristics of the effluent flow
resulting from a submerged single port diffuser
discharge, of arbitrary density (positively,
neutrally, or negatively buoyant) and arbitrary
location and geometry, into an ambient receiving
water body that may be stagnant or flowing and
have ambient density stratification of different
types.
CORMIX2 applies to three commonly
used types of submerged multiport diffuser
discharges under the same general effluent and
ambient conditions as CORMIX1. It analyzes
unidirectional, staged, and alternating designs of
multiport diffusers and allows for arbitrary
alignment of the diffuser structure within the
ambient water body, and for arbitrary
arrangement and orientation of the individual
ports. For complex hydrodynamic cases,
CORMIX2 uses the "equivalent slot diffuser"
concept and thus neglects the details of the
individual jets issuing from each diffuser port and
their merging process, but rather assumes that
the flow arises from a long slot discharge with
equivalent dynamic characteristics. Hence, if
details of the effluent flow behavior in the
immediate diffuser vicinity are needed, an
additional CORMIX1 simulation for an equivalent
partial effluent flow may be recommended.
CORMIX3 analyzes buoyant surface
discharges that result when an effluent enters a
larger water body laterally, through a canal,
channel, or near-surface pipe. In contrast to
CORMIX1 and 2, it is limited to positively or
neutrally buoyant effluents. Different discharge
geometries and orientations can be analyzed
including flush or protruding channel mouths, and
orientations normal, oblique, or parallel to the
bank.
Additional major assumptions include the
following:
All subsystems require that the actual
cross-section of the water body be
described as a rectangular straight
uniform channel that may be bounded
laterally or unbounded. The ambient
velocity is assumed to be uniform within
that cross-section.
In addition to a uniform ambient density
possibility, CORMIX allows for three
generic types of ambient stratification
profiles to be used for the approximation
of the actual vertical density distribution
(see Section 4.3).
All CORMIX subsystems are in principle
steady-state models, however recent
developments (beginning with Version
3.1) allow the analysis of unsteady
mixing in tidal environments.
All CORMIX systems can predict mixing
for both conservative and first-order decay
processes, and can simulate heat transfer
from thermal plumes.
3.2.2 Post-Processor Models CORJET and
FFLOCATR
CORJET, the Cornell Buoyant Jet Integral
Model, is a buoyant jet integral model that
predicts the jet trajectory and dilution
characteristics of a single round jet or of a series
of merging jets from a multiport diffuser with
arbitrary discharge direction and positive, neutral
or negative buoyancy in a general ambient
environment. The ambient conditions can be
highly non-uniform with both ambient current
magnitude, current direction, and density a
function of vertical distance. In general, CORJET
can be used as an enhancement to the near-field
predictions provided by CORMIX1 or 2 in order to
investigate local details that have been simplified
within the CORMIX representation. The major
limitation of CORJET lies in the assumption of an
infinite receiving water body, similar to all other
available jet integral type models. Thus, CORJET
should only be used after an initial CORMIX
classification has shown that the single or multiple
port discharge is indeed of the deep water type,
i.e. hydrodynamically stable, without boundary
interactions.
FFLOCATR, the Far-Field Plume Locator,
uses the cumulative discharge method to
delineate the CORMIX predicted far-field plume
18
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within the actual irregular (meandering or winding)
river or estuary channel geometry with uneven
distribution of the ambient flow.
3.3 System Processing Sequence and
Structure
The general CORMIX layout appears in
Figure 3.1, which shows the overall structure and
the execution sequence of the program elements.
The system has overall common data input
features for the three different discharge
elements. During program execution, the
elements are loaded automatically and
sequentially by the system. Each element
provides user interaction and prompting in
response to displayed information. This may
somewhat extend the total time required for a
single CORMIX session, but has offsetting benefit
of allowing the user to gain process knowledge
and insight on design sensitivity.
The user has numerous options with the
Main Menu at start-up. Option 1 is to start a new
CORMIX session. Option 2 is to re-run and
modify a former case. Option 3 is to simply re-
display (without new computation) results of a
former design case. Option 4 is to use the Post-
Processor. which includes the COR JET near-field
jet integral model, the FFLOCATR far-field
locator, and the plume display graphics which will
be discussed in Section V of this document.
Option 5 is the file manager which lists all files
from previous simulations. Option 6 is to
set/change CORMIX system speed. Here the
user can select REGULAR CORMIX, complete
with detailed queries and user help, or FAST-
CORMIX, which has terse questions and limited
user help. Option 7 contains system information
and reference material. Option 7 is to quit the
CORMIX system and return to DOS.
The common program elements of
CORMIX are composed of DATIN, PARAM,
CLASS, HYDRO, and SUM (Figure 3.1). DATIN
is the program element for the entry of data and
initialization of other program elements. PARAM
uses the input data to compute a number of
important physical parameters and length scales,
as precursor to CLASS which performs the
hydrodynamic classification of the given
discharge/ambient situation into one of many
possible generic flow configurations. HYDRO
performs the actual detailed numerical prediction
of the effluent plume characteristics. Finally, SUM
summarizes the results from the classification and
prediction, interprets them as regards mixing zone
regulations, suggests design alternatives, and
allows sensitivity analysis to be conveniently
conducted using the current input data. At this
point the iteration menu allows the user to
perform an iteration with different
ambient/discharge/regulatory conditions, or start
a new design case, or make use of the post-
processor options.
Due to its diverse programming
requirements, CORMIX is written in two
programming languages: VP-Expert, an "expert
systems shell", and Fortran. The former is
powerful in knowledge representation and logical
reasoning, while the latter is adept at
mathematical computations. Program elements
DATIN, PARAM, CLASS, and SUM are written
exclusively in VP-Expert. HYDRO is written in
VP-Expert, but uses three Fortran executables
HYDR01, 2 and 3 for the actual detailed
computation of plume characteristics. Finally,
C++ is used in the specially developed graphics
package CMXGRAPH.
3.4 CORMIX Data Input Features
All data is entered interactively in
response to the CORMIX system prompts
generated by the data input program element
DATIN. DATIN queries the user for a complete
specification of the physical environment of the
discharge, as well as the applicable regulatory
considerations for the situation undergoing
analysis. A CORMIX session commences with
questions on four topics which are asked
sequentially in this order: site/case descriptions,
ambient conditions, discharge characteristics, and
regulatory mixing zone definitions. Data entry is
entirely guided by the system and the available
advice menu options provide expanded
descriptions of the questions, if clarification is
needed.
Chapter IV provides complete details on
input specification for the three CORMIX
discharge subsystems. Chapter VI deals with the
input features of the post-processor models
CORJET and FFLOCATR.
19
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Figure 3.1: CORMIX system elements and processing sequence
20
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3.5 Logic Elements of CORMIX: Flow
Classification
To make predictions of an effluent
discharge's dilution and plume trajectory,
CORMIX typically combines the solutions of
several simple flow patterns to provide a complete
analysis from the efflux location all the way into
the far-field.
The logic processing elements of
CORMIX identify which solutions should be
combined to provide the complete analysis. This
process, called flow classification, develops a
generic qualitative description of the discharge
flow and is based on known relationships
between flow patterns and certain calculated
physical parameters.
PARAM is the program element that
computes relevant physical parameters including:
the various length scales, fluxes, and other values
needed for the execution of other program ele-
ments. Length scales are calculated measures of
the length of dynamic influence of various
physical processes (see Chapters IV and V).
At the heart of CORMIX is a flow
classification system contained in the program
element CLASS. It provides a rigorous and
robust expert knowledge base that carefully
distinguishes among the many hydrodynamic flow
patterns that a discharge may exhibit. As
examples, these possibilities include discharge
plumes attaching to the bottom, plumes vertically
mixing due to instabilities in shallow water,
plumes becoming trapped internally due to
density stratification, and plumes intruding
upstream against the ambient current due to
buoyancy, and many others. Theoretically based
hydrodynamic criteria using length scale analysis
and empirical knowledge from laboratory and field
experimentation, are applied in a systematic
fashion to identify the most appropriate flow
classification for a particular analysis situation.
For all three subsystems, a total of about 80
generic flow configurations or classes can be
distinguished.
The classification procedure of CORMIX
is based on technical principles and has been
verified by the developers through repeated
testing and data comparison. It has also
undergone independent peer review and the four
documentation manuals (5,6,7,8) give the detailed
scientific background for the classification
scheme, in form of a number of criteria. The
actual criteria constants are listed in the technical
reports with comments on their sources and
degree of reliability. Experienced users,
especially those involved in research applications,
may want to inspect these data values contained
in the source code and occasionally vary some
constant values within certain limits in order to
examine improved prediction fits with available
high-quality data. Extreme caution must be
exercised when doing that as some values are
interdependent; furthermore, if changes are
made, they should be carefully documented.
When CLASS has executed, a description
of the particular flow class is available to the user
in the form of on-screen or hardcopy computer
output; these description are also contained in the
documentation reports (5,6,7). It is recommended
that the novice or intermediate user review these
to gain an appreciation of the involved
hydrodynamic mixing processes.
3.6 Simulation Elements of CORMIX: Flow
Prediction
Once a flow has been classified, CORMIX
assembles and executes a sequence of
appropriate hydrodynamic simulation modules in
the program element HYDR01, 2 or 3. HYDRO
consists of: (a) control programs or "protocols" for
each hydrodynamic flow classification and (b) a
large number of subroutines or "simulation
modules" corresponding to the particular flow
processes, and their associated spatial regions,
that occur within a given flow classification. The
simulation modules are based on buoyant jet
similarity theory, buoyant jet integral models,
ambient diffusion theory, and stratified flow
theory, and on simple dimensional analysis, as
described elsewhere (5,6,7,8). The basic tenet of
the simulation methodology is to arrange a
sequence of relatively simple simulation modules
which, when executed together, predict the
trajectory and dilution characteristics of a complex
flow. Each of the simulation models uses the final
values of the previous module as "initial
conditions".
21
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3.7 CORMIX Output Features: Design
Summary and Iterations
In addition to the narrative feedback
during user input, the CORMIX system provides
three types of output on-screen or in print: a)
CORMIX Session Report that is a narrative
summary, mostly for regulatory evaluation, of all
discharge input data and global plume features,
including compliance with mixing zone
regulations, b) CORMIX1. 2 or 3 Prediction File
that is a detailed listing of all plume properties as
predicted by the Fortran program, and c)
CMXGRAPH Plots representing plan, side, and
trajectory views and concentration distribution of
the predicted plume.
3.7.1 CORMIX Session Report
SUM is the final program element that
summarizes the hydrodynamic simulation results
for the case under consideration. The output in
the CORMIX Session Report is arranged in four
groups:
(1) Site summary gives the site identifier
information, discharge and ambient environment
data, and discharge length scales.
(2) Hvdrodvnamic simulation and mixing zone
summary lists conditions at the end of the near-
field region (NFR), regulatory mixing zone (RMZ)
conditions, toxic dilution zone (TDZ) conditions,
region of interest (ROI) conditions, upstream
intrusion information, bank attachment locations,
and a passive diffusion mixing summary. Users
should be cognizant of the four major zone
definitions, and associated acronyms, introduced
above and defined as follows:
Near-Field Region (NFR): The NFR is
simply the zone of strong initial mixing,
corresponding to the "near-field"
processes discussed in Chapter II. It has
no regulatory implication whatsoever.
However, the information on size and
mixing conditions at the edge of the NFR
is given as a useful guide to the discharge
designer because mixing in the NFR is
usually sensitive to design conditions, and
therefore somewhat controllable. A
notable exception is the effluent discharge
into very shallow flow-limited streams
where the actual discharge port design
detail may have little bearing on instream
concentrations.
Regulatory Mixing Zone (RMZ): The
RMZ corresponds to either: (1) the
applicable mixing zone regulation with
specified size dimensions, or (2) a
preliminary proposal for a mixing zone
(see Section 2.2.4 (ii)).
Toxic Dilution Zone (TDZ): The TDZ
corresponds to the EPA's definition of
where toxic chemical concentrations may
exceed the CMC value (see Section
2.2.3).
Region of Interest (ROI): The ROI is a
user defined region of the receiving water
body where mixing conditions are to be
analyzed. It is specified as the maximum
analysis distance in the direction of mixed
effluent flow and is particularly important
when legal mixing zone restrictions do not
exist or when information over a larger
area is of interest.
(3) Data analysis section presents further details
on toxic dilution zone criteria, regulatory mixing
zone criteria, stagnant ambient environment
information, and region of interest criteria.
(4) Design recommendations section contains
design suggestions in three general areas for
improving initial dilution. These include: (a)
geometry variations in discharge port design, (b)
sensitivity to ambient conditions, and (c) process
variations in discharge flow characteristics. The
user is given guidance on the potential changes
in mixing conditions from varying parameter
values within these groups.
Finally, SUM is also used as an interactive
loop to guide the user back to DATIN to alter
design variables and perform sensitivity studies.
Different options for iteration exist on the iteration
menu depending on what input data changes are
to be made. The importance of performing an
ample number of CORMIX iterations cannot be
sufficiently stressed. To obtain a design that
22
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adequately meets water quality and engineering
construction objectives, it is necessary to get a
feel for the physical situation and its sensitivity to
design changes through repeated system use.
3.7.2 CORMIX1. 2 or 3 Prediction File
The CORMIX1, 2 or 3 Prediction File is a
detailed listing of all simulation input data as well
as the predicted plume properties (plume shapes
and concentration distributions) arranged by the
individual flow modules that form part of the
simulation. Additional information, such as
encounter of local mixing zone regulations, plume
contact with bottom or shoreline, etc., are listed in
the output. Detailed output features are
discussed in Chapter V.
3.7.3 CMXGRAPH Plots
The post-processing graphics package
CMXGRAPH can be exercised flexibly by the user
at different stages: directly after a CORMIX case
prediction for an initial evaluation of the design
case, or later to inspect or prepare plots for an
earlier design case, or outside the CORMIX
system to plot any plume predicted by CORMIX or
CORJET. The user can view different views of
the plume, with scaling and zooming possibilities.
Finally, hardcopy printouts can be prepared
through a direct print-screen option or by writing
to a Postscript file. Details of the graphics feature
are discussed in Chapter V.
3.8 Post-Processor Models CORJET and
FFLOCATR: Input and Output Features
The near-field jet integral model CORJET
and the far-field plume locator model FFLOCATR
can be exercised both within the CORMIX
system, with guided input data assembly, or
separately, with a simple Fortran input file. In
both cases, only limited data are needed.
Chapter VI provides a detailed discussion of the
data requirements.
The output from these models is displayed
on-screen or as a printed file. Furthermore,
CORJET output can also be plotted with the
CMXGRAPH program (see Section 5.3).
3.9 Equipment Requirements, System
Installation and Run Times
The minimum recommended hardware
configuration required for CORMIX is an IBM-
DOS compatible microcomputer with: (a) a
minimum of 550Kb of available RAM memory, (b)
approximately 3Mb of hard disk space, (c) DOS
3.3 or higher operating system, and (d) a
minimum 80386 with math co-processor to
provide acceptable performance, especially with
plume graphics display. The system will run on
systems with less advanced processors, however
simulation times can be long.
The RAM memory requirement of
CORMIX may present an obstacle to many users
because the configuration requirements of many
commercial applications packages and the
installation of memory resident software, or
running DOS from windows, frequently reduce
available RAM memory to less than 550Kb. The
amount of available RAM memory can be
determined with the DOS command CHKDSK.
Although there are numerous approaches for
increasing the size of a computer's available RAM
memory, the simplest way is "boot" the computer
from a floppy "system" disk that contains no
AUTOEXEC.BAT or CONFIG.SYS files which
consume additional memory. This should be done
just prior to beginning an analysis session since
it will temporary disable programs that consume
RAM memory. The CONFIG.SYS file should
allow the number of open files to be set to at least
20 by including the line statement "files=20". At
the completion of the analysis session, the
computer should be "booted" from the hard drive
to restore normal operations. A bootable floppy
system disk can be created with the DOS
command FORMAT a:/S.
The CORMIX must be installed on a hard
disk drive. The directory structure of CORMIX
(Table 3.1) is fixed; it gets set up during the
installation process; and it consists of a
subsystem root directory, called "CORMIX", and
six sub-directories. Complete installation
instructions are available with the CORMIX
distribution diskette.
Depending on computer configuration, a
typical CORMIX session for one
discharge/ambient condition may take less than 5
23
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minutes for an Pentium-based computer to about
20 minutes for an 80286-based computer if all
necessary input data is at hand. In some unusual
cases (such as attached flow classes, e.g. H1A5)
the numerical simulation routines in HYDROn
may take up to 10 minutes to converge on
Pentium-based systems.
Table 3.1
Directory Structure
CORMIX
Version 3.1 June 1995, Version 3.2 September 1996
Directory Name Comments
CORMIX
CORMIX\DATA
CORMIX\EXE
CORMIX\KBS
CORMIX\POST
CORMIX\POST\CJ
CORMIX\POST\FF
CORMIX\SIM
CORMIX\SIM\CXn
CORMIXYTEXT
system root directory; contains VP-Expert system files, the
knowledge base program CORMIX.kmp or kbs (system
driver), and the start-up batch file CMX.bat, and several other
batch files to be used for starting up CORJET, CMXGRAPH,
and FFLOCATR when used independently
contains cache "fact" files exported from knowledge base
programs
contains Fortran hydrodynamic simulation programs
HYDROn and file manipulation programs (*.exe)
contains all knowledge base programs (*.kmp or *.kbs)
contains three post-processor programs CORJET,
CMXGRAPH, and FFLOCATR
contains CORJET numerical prediction files (fn.CJT) and
graphical postscript files (fn.Pvn, where v = view type, and n
= 0 to 9)
contains FFLOCATR cumulative discharge input data files
(*.FFI) and prediction files (fn.FFX)
contains simulation results (Fortran files "fn.CXn", where n =
1,2,3, and fn = user designated filenames) and graphical
postscript files (fn.Pvn, where v = view type, and n = 0 to 9)
contains simulation data files for each subsystem n (cache
files "fn.CXC" and record keeping file "summary")
contains all user-requested advice files and flow descriptions
(*.txt)
24
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IV CORMIX Data Input
4.1 General Aspects of Interactive Data Input
All CORMIX data input occurs interactively
in response to system prompts and is entirely
guided by the system. The user is automatically
prompted for a complete specification of:
site/case descriptions, ambient conditions,
discharge characteristics, and regulatory defini-
tions. The data for each of these four topical
areas are called input data sequences herein.
Questions are asked in plain English. Advice
menu options within the program are available to
provide help on how to prepare and enter data
values when clarification of the system prompts is
needed. The contents of these are also available
in the documentation reports (5,6,7).
Regular CORMIX versus FAST-CORMIX:
Upon in its initial installation the CORMIX system
speed is set to "Regular CORMIX". In this mode
the user will see detailed input questions with
ample explanations for each variable. Also there
will be opportunities to consult advice sections. It
is recommended that the novice user employ this
mode for about a dozen or so CORMIX sessions
until he/she has become thoroughly familiar with
the system. The advanced user can switch to the
"FAST-CORMIX" mode in which only short
questions are asked, thereby greatly accelerating
data input and compacting it on screen. Certain
advice section are not available. The differences
are illustrated in the following:
Examples of three questions asked in Regular CORMIX:
1) Do you want detailed ADVICE on how to specify the ambient density
stratification?
[no] [yes]
2) Can the ambient density be considered 'UNIFORM' throughout the water column,
or
is there a 'NON-UNIFORM' vertical density stratification?
As practical guideline, uniformity can be assumed if the vertical density
variation between top and bottom is limited to 0.1 kg/m^3 or the temperature
variation to 1 degC.
[uniform] [non-uniform]
3) What is the WIDTH of the channel in the vicinity of the discharge (m)?
Corresponding questions in FAST-CORMIX:
1)
2) AMBIENT DENSITY?
[uniform] [non-uniform]
3) Channel WIDTH (m)?
Data can be entered in an open format
without concern for letter case or decimal
placement. The only constraint is that the
following characters may not be entered in
response to any question:
+ = {},<> I \ ;
The system checks data entries for
consistency with question type (e.g. an alphabetic
character for water depth), obvious physical errors
(e.g. a negative length), possible inconsistencies
with previous entries (e.g. an angular value
implying that a port points directly back to the
25
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shoreline) and situations outside the ranges of
model applicability. Inconsistency with question
type and obvious physical errors require
immediate re-entry while possible inconsistencies
with previous entries lead to a warning label and
the opportunity for later correction. Entries
specifying situations outside the ranges of model
applicability usually require the re-entry of the
entire data segment.
Warning: No attempt should be made to
alter input data by manipulating any of the data
files that are used by the HYDROn Fortran
programs and execute these programs separately
without using the VP-Expert segments DATIN,
PARAM, and CLASS. Because of the inherent
error and compatibility checking of input data
within these program segments, unreliable
prediction may result if they are by-passed!
As discussed in Chapter III, data input
occurs in three or four program segments that
load automatically. At the end of each data
sequence (usually of the order of 5 to 20 items
long) the entire sequence is displayed and the
user is requested to accept or not accept the
sequence. If it is not accepted, i.e. an error has
been made, the user has another opportunity for
entering the sequence. If an error is detected
earlier there is no way of correcting immediately,
it is best then to give a short answer (e.g. the
value of 1) to all remaining questions and thus
quickly move to the end of the sequence for the
re-start opportunity.
Due to the similarity of data entry, a
common description is given for all input data
sequences, except discharge data to which a
separate subsection for each CORMIXn
subsystem is devoted below. Further guidance
on data specification can be obtained from
examining the case studies in the Appendices
and from the documentation manuals (5,6,7).
Following the discussion of input data sequences,
units of measure conversion factors and
checklists for input preparation are presented.
All the data input requirements of
CORMIX are included in the Checklist for Data
Preparation (see following page) that can be
photocopied by the reader for future multiple use.
The checklist aids in the assembly and
preparation of this data prior to beginning an
analysis to verify that all necessary data are
available.
4.2 Site/Case Identifier Data
The first input data sequence determines
basic information needed for the program to
operate. These include: a two-part identifier for
labeling output and a computer file name.
It is necessary to specify three site/case
labels that facilitate the rapid identification of
printed output and aid in good record-keeping.
The system provides for one label called SITE
NAME (e.g. Blue River), another called DESIGN
CASE (e.g. 7Q10-low-flow, or High-velocity-port).
The user needs to supply a DOS-
compatible FILE NAME, up to eight characters
long, and without extension (e.g. sdif7q10).
CORMIX will use that user-specified file name fn,
and create, transfer, or store intermediate or final
data files with that same file name, but with
different extensions. The most important of these
are the two output data files, SIM\/h.CXn and
SIM\CXn\/h.CXC, where n = 1, 2 or 3, which are
discussed further in Chapter V.
4.3 Ambient Data
Ambient conditions are defined by the
geometric and hydrographic conditions in the
vicinity of the discharge. Due to the significant
effect of boundary interactions on mixing
processes, the ambient data requirements for the
laterally bounded and unbounded analysis
situations are presented separately in the
discussions below. CORMIX analyses, as all
mixing zone evaluations, are usually carried out
under the assumption of steady-state ambient
conditions. Even though the actual water
environment is never in a true steady-state, this
assumption is usually adequate since mixing
processes are quite rapid relative to the time
scale of hydrographic variations. In highly
unsteady tidal reversing flows the assumption
is no longer valid and significant concentration
build-up can occur. CORMIX will assess this
situation and compute some re-entrainment
effects on plume behavior. The data requirements
for that purpose are discussed in the Section
4.3.3. Following are discussions on ambient
26
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CHECKLIST FOR DATA PREPARATION
CORMIX - CORNELL MIXING ZONE EXPERT SYSTEM - Version 3.00-3.20
SITE Name
Design CASE
DOS FILE NAME
Date;
Prepared by:
jw/o extension)
AMBIENT DATA;
Water body depth
Depth at discharge
If steady: Ambient Flowrate
m
m
Water body is
If bounded: Width
bounded/unbounded
m
ililpli
At time
Appearance 1/2/3
m is or: Ambient velocity
alls
Manning's n
Wind speed
Density data:
Water body is
If uniform:
S SfeitifiM:
Stratification type
llllgfciiillllillliHi
or: Darcy-Weisbach f
m/s
iiiii
mil
m/s
fresh/salt water
9991m
Igif
UNITS: Density...kg/m1 / Temperature...°C
If fresh: Specify as density/temp, values
Average density/temp,
DISCHARGE DATA:
Specify geometry for CORM1X1 or 2 or 3
SUBMERGED SINGLE PORT DISCHARGE - CORMIX1
Nearest bank is on left/right Distance to nearest bank
Vertical angle THETA " Horizontal angle SIGMA
Port diameter m or: Port area
Port heii " ' _
m
Q
m2
SUBMERGED MULTIPORT DIFFUSER DISCHARGE ~ CORMIX2
Nearest bank is on left/right Distance to one endpoint _
Diffuser length m to other endpoint _
Total number of openings m Port height
Port diameter _____ m with contraction ratio
Diffuser arrangement/type unidirectional / staged / alternating or vertical
Alignment angle GAMMA 0 Horizontal angle SIGMA _
Vertical angle THETA 0 Relative orientation BETA
m
m
m
BUOYANT SURFACE DISCHARGE - CQRMIX3
Discharge located on
Horizontal angle SIGMA
Depth at discharge
If rectangular Width
discharge channel: Depth
left/right bank
m
m or.
m
Configuration flush/protruding/co-flowing
If protruding: Dist. from bank rrs
Bottom slope ,J>
If circular Diameter m
pipe: Bottom invert depth
m
Effluent: Flow rate _____
Effluent density
Heated discharge? yes/no
Concentration units
Conservative substance? yes/no
m /s or
,3
_kg/nrr
Effluent velocity
or: Effluent temperature
If yes: Heat loss coefficient
Effluent concentration
If no: Decay coefficient
m/s
aC
W/rrr
/day
MIXING ZONE DATA:
Is effluent toxic? yes/no
WQ stand./conventional poll.? yes/no
Any mixing zone specified? yes/no
(f yes
If yes
If yes
CMC
value of standard
distance m
Apr*
www
or width
or area
% or m
% or m:
Regi iterest
m
Grid intervals for display
-------
density specification and on wind effects.
CORMIX requires that the actual cross-
section of the ambient water body be described
by a rectangular channel that may be bounded
laterally or unbounded. Furthermore, that
channel is assumed to be uniform in the
downstream direction, following the mean flow of
the actual water body that may be non-uniform or
meandering. The process of describing a
receiving water body's geometry with a
rectangular cross-section is herein called
schematization.
Additional aids exist for the CORMIX user
for interpreting plume behavior in the far-field of
actual non-uniform (winding or meandering) flows
in rivers or estuaries (see Section 6.2 for the post-
processor option FFLOCATR).
The first step towards specifying the
ambient conditions is to determine whether a
receiving water body should be considered
"bounded" or "unbounded." To do this, as well
as answer other questions on the ambient
geometry, it is usually necessary to have access
to cross-sectional diagrams of the water body.
These should show the area normal to the
ambient flow direction at the discharge site and at
locations further downstream. If the water body is
constrained on both sides by banks such as in
rivers, streams, narrow estuaries, and other
narrow watercourses, then it should be
considered "bounded." However, in some cases
the discharge is located close to one bank or
shore while the other bank is for practical
purposes very far away. When interaction of the
effluent plume with that other bank or shore is
impossible or unlikely, then the situation should
be considered "unbounded." This would include
discharges into wide lakes, wide estuaries, and
coastal areas.
4.3.1 Bounded Cross-Section
Both geometric (bathymetric) and hydrographic
(ambient discharge) data should be used for
defining the appropriate rectangular cross-
section. This schematization may be quite
evident for well-channeled and regular rivers or
artificial channels. For highly irregular
cross-sections, it may require more judgment and
perhaps several iterations of the analysis to get a
better feel on the sensitivity of the results to the
assumed cross-sectional shape.
In any case, the user is advised to
consider the following comments:
a) Be aware that a particular flow condition
such as a river discharge is usually associated
with a certain water surface elevation or "stage."
Data for a stage-discharge relationship is nor-
mally available from a USGS office; otherwise it
can be obtained from a separate hydraulic
analysis or from field measurements.
In the simplest case of a river flow, if river
depth is known for a certain flow condition
(subscript 1 in the following) corresponding
perhaps to the situation at the time of a field
study, then the depth for a given design (e.g. low)
flow (subscript 2) can be predicted from
Manning's equation
HA2 = HA1
OA.
OA,
in which QA is the ambient river flow and HA the
mean ambient depth. This approach assumes
that the both the ambient width and frictional
characteristics of the channel (i.e. Manning's n)
remain approximately the same during such a
stage change.
b) For the given stage/river discharge
combination to be analyzed, assemble plots
showing the cross-sections at the discharge and
several downstream locations. Examine these to
determine an "equivalent rectangular
cross-sectional area." Very shallow bank areas or
shallow floodways may be neglected as
unimportant for effluent transport. Also, more
weight should be given to the cross-sections at,
and close to, the discharge location since these
will likely have the greatest effect on near-field
processes. Figure 4.1a provides an example of
the schematization process for a river or estuary
cross-section.
28
-------
"Nearest bank
on the right"
a) Example: Bounded Cross-Section Looking Downstream
(River or Estuary)
"Nearest bank on the left"
b) Example: Unbounded Cross-Section Looking Downstream
(Small Buoyant Jet Discharge Into Large Lake
or Reservoir)
Figure 4.1: Examples of the schematization process for preparing CORMIX input data on ambient
cross-sectional conditions
29
-------
c) The input data values for surface width
(BS) and (average) depth (HA) should be
determined from the equivalent rectangular cross-
sectional area. When ambient discharge and
ambient velocity data are available, the
reasonableness of the schematization should be
checked with the continuity relation. It specifies
that ambient discharge equals velocity times
cross-sectional area, where the area is given by
the product of average width and depth.
The discussion of the cumulative
discharge method (see Section 6.2 and Figure 6.2
for an illustration) will provide further perspective
on the choice of these variables.
d) CORMIX also requires specification of
the actual water depth (HD) in the general
discharge location to describe local bathymetric
features. A check is built in allowing the local
depth HD not to differ from the schematized
average depth HA by more than +/- 30%. This
restriction is included to prevent CORMIX misuse
in several discharge/ambient combinations
involving strongly non-uniform channels.
Alternative schematizations can be explored by
the user to work around the restriction. The
choice for these alternatives may be influenced
somewhat by the expected plume pattern. As an
example, Figure 4.1b illustrates a small buoyant
discharge that is located on the side slope of a
deep reservoir and that is rising upward. In this
situation, the correct representation of the deeper
mean reservoir depth is irrelevant for plume
predictions. Although the illustration is for an
unbounded example, the comments on choice of
HA apply here, too.
When schematizing HA and HD in highly
non-uniform conditions, HD is the variable that
usually influences near-field mixing, while HA is
important for far-field transport and never
influences the near-field.
e) The ambient discharge (QA) or mean
ambient velocity (UA) may be used to specify
the ambient flow condition. Depending which is
specified, the program will calculate and display
the other. The displayed value should be
checked to see whether it is consistent with
schematizations and continuity principles
discussed above.
The simulation of stagnant conditions
should usually be avoided. If zero or a very small
value for ambient velocity or discharge is entered,
CORMIX will label the ambient environment as
stagnant. In this case, CORMIX will predict only
the near-field of the discharge, since steady-state
far-field processes require a mean transport
velocity. Although stagnant conditions often, but
not necessarily always, represent the extreme
limiting case for a dilution prediction, a real water
body never is truly stagnant. Therefore, a more
realistic assumption for natural water bodies
would be to consider a small, but finite ambient
crossflow.
f) As a measure of the roughness
characteristics in the channel the value of
Manning's n, or alternatively of the
Darcy-Weisbach friction factor f, must be
specified. Friction values are useful for
applications in laboratory studies. If Manning's n
is given, as is preferable for field cases, CORMIX
internally converts it to an f friction value using the
following equation
in which g = 9.81 m/s2.
The friction parameters influence the
mixing process only in the final far-field diffusion
stage, and do not have a large impact on the
predictions. Generally, if these values can be
estimated within +/-30%, the far-field predictions
will vary by +/-10% at the most. The following list
is a brief guide for specification of Manning's n
values; additional details are available in
hydraulics textbooks (e.g. 24).
g) The channel appearance can have an
effect on the far field mixing by increasing
turbulent diffusivity for the passive mixing
process, but will not significantly affect near-field
mixing. Three channel appearance types are
allowed in CORMIX. Type 1 are fairly straight and
uniform channels. Type 2 have moderate
downstream meander with a non-uniform
channel. Type 3 are strongly winding and have
highly irregular downstream cross-sections.
30
-------
Channel type Manning's n
Smooth earth channel, no weeds 0.020
Earth channel, some stones and weeds 0.025
Clean and straight natural rivers 0.025 - 0.030
Winding channel, with pools and shoals 0.033 - 0.040
Very weedy streams, winding, overgrown 0.050 - 0.150
Clean straight alluvial channels 0.031 d1/6
(d = 75% sediment grain size in feet)
4.3.2 Unbounded Cross-section
Both hydrographic and geometric
information are closely linked in this case. The
following comments apply:
a) From lake or reservoir elevation or tidal
stage data, determine the water depth(s) for the
receiving water condition to be analyzed.
b) For the given receiving water condition
to be analyzed, assemble plots showing water
depth as a function of distance from the shore for
the discharge location and for several positions
downstream along the ambient current direction.
c) If detailed hydrographic data from field
surveys or from hydraulic numerical model
calculations are available, determine the
"cumulative ambient discharge" from the shore
to the discharge location for the discharge
cross-section. For each of the subsequent
downstream cross-sections, determine the
distance from the shore at which the same
cumulative ambient discharge has been attained.
Mark this position on all cross-sectional profiles.
Examine the vertically averaged velocity and the
depth at these positions to determine typical
values for the ambient depth (HA) and ambient
velocity (UA) input specifications. The conditions
at, and close to, the discharge location should be
given the most weight. The distance from the
shore (DISTB) for the outfall location is typically
specified as the cumulative ambient discharge
divided by the product UA times HA.
When detailed hydrographic data are
unavailable, data or estimates of the vertically
averaged velocity at the discharge location can be
used to specify HA, UA, and DISTB. First,
determine the cumulative cross-sectional area
from the shore to the discharge location for the
discharge cross-section. For each of the
subsequent downstream cross-sections, mark the
position where the cumulative cross-sectional
area has the same value as at the discharge
cross-section. Then proceed as discussed in the
preceding paragraph.
d) The specification of the actual water
depth at the submerged discharge location
(HD) in CORMIX1 and 2 is governed by
considerations that are similar to those discussed
earlier for bounded flow situations discussed
above. Figure 4.1b shows an illustration of the
schematization for a small buoyant discharge
located on the side slope of a deep reservoir.
The plume is expected to rise upward and stay
close to one shore, with bottom contact and
vertical mixing not expected. In this situation, no
emphasis on replicating the mean reservoir depth
and the actual width is necessary. However, care
must still be taken to specify an ambient mean
velocity that is: (a) characteristic of the actual
reservoir and (b) not determined using the
reduced depth assumption.
The specification of HD for CORMIX3 is
dictated by the depth condition some distance
offshore from the discharge exit. It does not
describe the conditions immediately in front of the
discharge channel exit. When in doubt, set HD
simply equal to HA in the CORMIX3 case.
e) Either Manning's n or the Darcy-
Weisbach friction factor f can be specified for
the ambient roughness characteristics as
31
-------
described previously for the bounded case (see
above). If the unbounded case represents a large
lake or coastal area, it is often preferable to use
the friction factor f. Typical f values for such open
water bodies range from 0.020 to 0.030, with
larger values for rougher conditions.
4.3.3 Tidal Reversing Ambient Conditions
When predictions are desired in an
unsteady ambient flow field, information on the
tidal cycle must be supplied. In general, estuaries
or coastal waters can exhibit considerable
complexity with variations in both velocity
magnitude, direction and water depth. As an
example, Figure 4.2 shows the time history of tidal
velocities and tidal height for a mean tidal cycle at
some site in Long Island Sound. The tidal height
varies between mean Low Water (MLW) and
Mean High water (MHW).
The tidal velocity changes its direction
twice during the tidal cycle at times called slack
tide. One of these times occurs near, but is not
necessarily coincident with, the time MLW and is
referred to as Low Water Slack (LWS). The slack
period near MHW is referred to as High Water
Slack (HWS). The rate reversal (time gradient of
the tidal velocity) near these slack tides is of
considerable importance for the concentration
build-up in the transient discharge plume, as tidal
reversals will reduce the effective dilution of a
discharge by re-entraining the discharge plume
remaining from the previous tidal cycle (8).
Hence, CORMIX needs some information on the
ambient design conditions relative to any of the
two slack tides.
Figure 4.2: Example of tidal cycle, showing stage and velocity as a function of time after Mean
High Water (MHW)
32
-------
The tidal period (PERIOD) must be
supplied; in most cases it is 12.4 hours, but in
some locations it may vary slightly. The
maximum tidal velocity (UAmax) for the location
must be specified; this can usually be taken as
the average of the absolute values of the two
actual maxima, independent of their direction. A
CORMIX design case consists then of an
instantaneous ambient condition, before, at or
after one of the two slack tides. Hence, the
analyst must specify the time (in hours) before,
at, or after slack that defines the design
condition, followed by the actual tidal ambient
velocity (UA) at that time. The ambient depth
conditions are then those corresponding to that
time.
In general, tidal simulations should be
repeated for several time intervals (usually hourly
or two-hourly intervals will suffice) before and
after slack time to determine plume
characteristics in unsteady ambient conditions.
Strongly unsteady conditions can also
occur in other environments, such as in wind-
induced current reversals in shallow lakes or
coastal areas. In this case, any typical reversal
period can be analyzed following an approach
similar to the above.
4.3.4 Ambient Density Specification
Information about the density distribution
in the ambient water body is very important for the
correct prediction of effluent discharge plume
behavior. CORMIX first inquires whether the
ambient water is fresh water or non-fresh (i.e.
brackish or saline). If the ambient water is fresh
and above 4 °C, the system provides the option of
entering ambient temperature data so that the
ambient density values can be internally
computed from an equation of state. This is the
recommended option for specifying the density of
fresh water, even though ambient temperature
per se is not needed for the analysis of mixing
conditions. In the case of salt water conditions,
Figure 4.3 is included as a practical guide for
specifying the density if "salinity values" in parts-
per-thousand (ppt) are available for the water
body. Typical open ocean salinities are in the
range 33 - 35 ppt.
The user then specifies whether the
ambient density (or temperature) can be
considered as uniform or as non-uniform within
the water body, and in particular within the
expected plume regions. As a practical guide,
vertical variation in density of less than 0.1 kg/m3
or in temperature of less than 1 °C can be
neglected. For uniform conditions, the average
ambient density or average temperature must
be specified.
When conditions are non-uniform,
CORMIX requires that the actual measured
vertical density distribution be approximated by
one of three schematic stratification profile types
illustrated in Figure 4.4. These are: Type A, linear
density profile; Type B, two-layer system with
constant densities and density jump; Type C,
constant density surface layer with linear density
profile in bottom layer separated by a density
jump. Corresponding profile types exist for
approximating a temperature distribution when it
is used for specifying the density distribution.
Note: When in doubt about the
specification of the ambient density values it is
reasonable to first simplify as much as possible.
The sensitivity of a given assumption can be
explored in subsequent CORMIX simulations.
Furthermore, if CORMIX indicates indeed a flow
configuration (flow class) with near-field stability,
additional studies with the post-processor option
COR JET (see Section 6.1) can be performed to
investigate any arbitrary density distribution.
After selecting the stratification
approximation to be used, the user then enters all
appropriate density (or temperature) values and
pycnocline heights (HINT) to fully specify the
profiles. The pycnocline is defined as zone or
level of strong density change that separates the
upper and lower layers of the water column. The
program checks the density specification to insure
that stable ambient stratification exists (i.e. the
density at higher elevations must not exceed that
at lower elevations).
Note that a dynamically correct
approximation of the actua Idensity distribution
should keep a balance between over-and
under-estimationof the actual data similar to a
best-fit in regression analysis. If simulation
results indicate internal plume trapping, then it is
33
-------
SEAWATER DENSITY (
-------
desirable to test --through repeated use of
CORMIX-- different approximations (i.e. with
different stratification types and/or parameter
values) in order to evaluate the sensitivity of the
resulting model predictions.
4.3.5 Wind speed
When specifying the wind speed (UW) at
design conditions, it should be kept in mind that
the wind is unimportant for near-field mixing, but
may critically affect plume behavior in the far-field.
This is especially important for heated discharges
in the buoyant spreading regions. Wind speed
data from adjacent meteorological stations is
usually sufficient for that purpose.
The following guidelines are useful when
actual measured data are not available. The
typical wind speed categories measured at the 10
m level are:
breeze (0-3 m/s)
light wind (3-15 m/s)
strong wind (15-30 m/s)
If field data are not available, consider using the
recommended value of 2 m/s to represent
conservative design conditions. An extreme low
value of 0 m/s is usually unrealistic for field
conditions, but useful when comparing to
laboratory data. A wind speed of 15 m/s is the
maximum value allowed in CORMIX.
4.4. Discharge Data: CORMIX1
Figure 4.5a is a definition sketch giving the
geometry and flow characteristics for a
submerged single port discharge within the
schematized cross-section.
4.4.1 Discharge Geometry
To allow the establishment of a reference
coordinate system and orient the discharge to that
reference, CORMIX1 requires the specification of
6 data entries. These specifications are illustrated
in Figure 4.5a and include: (a) location of the
nearest bank (i.e. left or right) as seen by an
observer looking downstream in the direction of
the flow, (b) distance to the nearest bank
(DISTB), (c) port radius (or cross-sectional area
for non-circular shaped ports) {Note: The
specification of the port dimension should account
for any contraction effects that the effluent jet may
experience upon leaving the port/nozzle!) , (d)
height of the port (HO) center above the bottom,
(e) vertical angle of discharge (THETA)
between the port centerline and a horizontal
plane, and (f) horizontal angle of discharge
(SIGMA) measured counterclockwise from the
ambient current direction (x-axis) to the plan
projection of the port centerline. Angle THETA
may range between -45° and 90°. As examples,
the vertical angle is 90° for a discharge pointing
vertically upward, and it is 0° for a horizontal
discharge. Angle SIGMA may range between 0°
and 360 °. As examples, the horizontal angle is
0° (or 360 °) when the port points downstream in
the ambient flow direction, and it is 90°, when the
port points to the left of the ambient flow direction.
In order to prevent an inappropriate
system application, CORMIX1 checks the
specified geometry for compliance with the three
criteria illustrated in Figure 4.5b. These are: (a)
the port height (HO) value must not exceed one-
third of the local water depth (HD) value, (b) the
port diameter value must not exceed HD's value
for near-vertical designs, and one-third of HD's
value for near-horizontal designs, and (c) the
pycnocline value must be within the 40 to 90
percent range of HD's value. The port height
restriction results from the fact that CORMIX1
only applies to submerged discharge applications.
In ordinary design practice, submerged
implies a discharge close to the bottom, and not
anywhere within the main water column or near
the water surface. The port diameter restriction
excludes very large discharge diameters relative
to the actual water depth since these are
unrealistic and/or undesirable. The distance
separating the upper and lower layers of the
ambient density profile type B or C is restricted in
order to prevent: (a) discharges into the upper
layer or (b) an unrealistically thick plume relative
to a thin upper layer. For those few extreme
situations that would normally be limited by the
above restrictions, Section 7.4 of Doneker and
Jirka (5) contains a number of hints on how to
conduct these difficult analyses; only advanced
users should attempt these techniques.
35
-------
" ^ <
BS
y|
.<
^ho
D, U0, APq,
a) Definition Diagram CORMIX1 (Special case: HA = HD)
b) Limits of Applicability CORMIX1
Figure 4.5: CORMIX1 discharge geometry and restrictions
36
-------
4.4.2 Port Discharge Flow
For discharge characteristics, CORMIX1
requires the specification of 3 data entries. These
specifications include: (a) the discharge flow
rate (QO) or discharge velocity (UO), (b) the
discharge density or discharge temperature for
an essentially freshwater discharge, and (c) the
discharge concentration of the material of
interest. The QO and UO variables are related
through the port cross-sectional area and the
program computes and displays the alternate
value allowing for user inspection and verification.
For a freshwater discharge, discharge density can
be directly related to temperature via an equation
of state since the addition of any pollutant or
tracer has negligible effect on density.
The specification of the pollutant in the
effluent is described in Section 4.7 below.
4.5 Discharge Data: CORMIX2
A generalized definition sketch showing
the geometry and flow characteristics for a typical
multiport diffuser installation is provided in
Figure 4.6a. Due to the great number of
complexities which may rise in describing an
existing or proposed diffuser design, a few
definitions are introduced prior to discussing
actual data requirements of CORMIX2.
A multiport diffuser is a linear structure
consisting of many more or less closely spaced
ports or nozzles which inject a series of turbulent
jets at high velocity into the ambient receiving
water body. These ports or nozzles may be
connected to vertical risers attached to an
underground pipe or tunnel or they may simply be
openings in a pipe lying on the bottom.
The diffuser line (or axis) is a line
connecting the first port or nozzle and the last port
or nozzle. Generally, the diffuser line will coincide
with the connecting pipe or tunnel. CORMIX2 will
assume a straight diffuser line. If the actual
diffuser pipe has bends or directional changes it
must be approximated by a straight diffuser line.
The diffuser length is the distance from
the first to the last port or nozzle. The origin of
the coordinate system used by CORMIX2 is
located at the center (mid-point) of the diffuser
line. The only exception is when the diffuser line
starts at the shore; then the origin is located
directly at the shore.
CORMIX2 can analyze discharges from
the three major diffuser types used in common
engineering practice. These are illustrated in
Figure 4.7 and include: (a) the unidirectional
diffuser where all ports (or nozzles) point to one
side of the diffuser line and are oriented more or
less normally to the diffuser line and more or less
horizontally; (b) the staged diffuser where all
ports point in one direction generally following the
diffuser line with small deviations to either side of
the diffuser line and are oriented more or less
horizontally; and (c) the alternating diffuser
where the ports do not point in a nearly single
horizontal direction. In the latter case, the ports
may point more or less horizontally in an
alternating fashion to both sides of the diffuser
line or they may point upward, more or less
vertically.
4.5.1 Diffuser Geometry
CORMIX2 assumes uniform discharge
conditions along the diffuser line. This includes
the local ambient receiving water depth (HD) and
discharge parameters such as port size, port
spacing and discharge per port, etc. If the actual
receiving water depth is variable (e.g. due to an
offshore slope), it should be approximated by the
mean depth along the diffuser line with a possible
bias to the more shallow near-shore conditions.
Similarly, mean values should be used to specify
variable diffuser geometry when it occurs.
To allow the establishment of a reference
coordinate system and orient the discharge to that
reference, CORMIX2 requires the specification of
13 data entries. These specifications are
illustrated in Figure 4.6a and include: (a) location
of the nearest bank (i.e. left or right) as seen by
an observer looking downstream in the direction
of the flow, (b) average distance to the nearest
bank (DISTB), (c) average diameter (DO) of the
discharge ports or nozzles, (d) contraction ratio
for the port/nozzle is required (This can range
from 1 for well rounded ports -usual value- down
to 0.6 for sharp-edged orifices), (e) average
37
-------
///////////////J?//'/*////;/.
Nearest Bank
Cross-Section
^0* ^Po' co
a) Definition Diagram C0RMIX2
hint=0.9H
Density profile
example
Range
°f hin»
hint=0.4H
h0=0.33H
Range
of hft
D< H/5
Range
of D
b) Limits of Applicability C0RMIX2
Figure 4.6: C0RMIX2 discharge geometry and restrictions
38
-------
GJ
CD
1
I
1
ic"
i
L
•
0
•
•—
«
T®
[•
1
4
ic<
/9 s 90°
/3<90°
/3ave=90°
Without control
a) Unidirectional diffuser designs, 0o = O
»
Control; Fanned design
2y"
Lo
«¦»' It'0' 2).
Lo
0=0
0ZO
0ave ' 0°
Kl 1111111' vs }
t t t t t t 0*t&
1 t i Hi-1 - -
80 < 90°
c
o
)"
\S \S \y \/ \/ /3OVa»±90°
/V7V7V7V7VA ft, <90°
f O OOOQOOOOOQl
Vertical
9a - 90°
»))H1H<«
Control:
Fanned design
&*t cot"
. 2y*
Lo
c) Alternating diffuser designs, S030
0
*2/ -rr 0iO .
^^^payt = 0
b) Staged diffuser designs, 0O= 0
Figure 4.7: Configurations of common multiport diffuser types
-------
height of the port centers (HO) above the
bottom, (f) average vertical angle of discharge
(THETA) between the port centerlines and a
horizontal plane (-45 and 90°), (g)for the
unidirectional and staged diffusers only, the
average horizontal angle of discharge (SIGMA)
measured counterclockwise from the ambient
current direction (x-axis) to the plan projection of
the port centerlines (0 to 360°), (h) approximate
straight-line diffuser length (LD) between the
first and last ports or risers, (I) distance from the
shore to the first and last ports or risers (YB1,
YB2) of the diffuser line, 0 number of ports or
risers and the number of ports per riser if risers
are present, (k) average alignment angle
(GAMMA) measured counterclockwise from the
ambient current direction (x-axis) to the diffuser
axis (0 to 180 °), and (I) for the unidirectional and
staged diffusers only, relative orientation angle
(BETA) measured either clockwise or
counterclockwise from the average plan
projection of the port centerlines to the nearest
diffuser axis (0 to 90°). Note that CORMIX2
always assumes a uniform spacing between
risers or between ports, and a round port cross-
sectional shape.
As examples of angle specifications,
THETA is 0 degrees for a horizontal discharge
and it is +90 degrees for a vertically upward
discharge, SIGMA is 0 degrees (or 360°) when
the ports point downstream in the ambient flow
direction and it is 90 degrees when the ports point
to the left of the ambient flow direction, GAMMA
is 0 degrees (or 180°) for a parallel diffuser and it
is 90 degrees for a perpendicular diffuser, and
BETA is 0 degrees for a staged diffuser and it is
90 degrees for a unidirectional diffuser.
CORMIX2 performs a number of
consistency checks to ensure the user does not
make arithmetical errors when preparing and
entering the above data and it also checks the
specified geometry for compliance with three
criteria to prevent an inappropriate system
application. Figure 4.6b shows the imposed limits
of system application for CORMIX2 which are: (a)
the port height (HO) value must not exceed one-
third of the local water depth (HD) value, (b) the
port diameter value must not exceed one-fifth of
HD's value, and (c) the pycnocline value must be
within the 40 to 90 percent range of HD's value.
The restrictions are similar to those shown in
Figure 4.5b for CORMIX1 with the exception of
the diameter limit for each port.
4.5.2 Diffuser Discharge Flow
For discharge characteristics, CORMIX2
requires the specification of 3 data entries. These
specifications include: (a) the total discharge
flow rate (Q0) or discharge velocity (U0), (b) the
discharge density or discharge temperature for
an essentially freshwater discharge, and (c) the
discharge concentration of the material of
interest. The Q0 and U0 variables are related
through the total cross-sectional area of all
diffuser ports and the program computes and
displays the alternate value allowing for user
inspection and verification.
The specification of the pollutant in the
diffuser effluent is described in Section 4.7 below.
4.6 Discharge Data: CORMIX3
A definition sketch for the discharge
geometry and flow characteristics for a buoyant
surface discharge is provided in Figure 4.8. In
general, CORMIX3 allows for different types of
inflow structures, ranging from simple rectangular
channels to horizontal round pipes that may be
located at or near the water surface. In addition,
three different configurations relative to the bank
are allowed as illustrated in Figure 4.9. Discharge
structures can be: (a) flush with the bank/shore,
(b) protruding from the bank or (c) co-flowing
along the bank.
4.6.1 Discharge Geometry
To allow the establishment of a reference
coordinate system and orient the discharge to that
reference, CORMIX3 requires the specification of
up to 7 data entries. These specifications are
illustrated in Figure 4.8 and include: (a) location of
the nearest bank (i.e. left or right) as seen by an
observer looking downstream in the direction of
the flow, (b) discharge channel width (B0) of the
rectangular channel, (c)discharge channel
depth (HO), (d) actual receiving water depth at
the channel entry (HD0) and (e) bottom slope
(SLOPE) in the receiving water body in the vicinity
of the discharge channel, and (f)horizontal angle
of discharge (SIGMA) measured counterclock-
wise from the ambient current direction (x-axis) to
40
-------
/Discharge Angle, cr
Discharge
a) Plan View
Figure 4.8: C0RMIX3 discharge channel geometry
41
-------
a) Discharge flush with bank
c) Coflowing along downstream bank
Figure 4.9: Possible C0RMIX3 discharge configurations of discharge channel relative to
bank/shoreline
42
-------
the plan projection of the port centerline. In the
case of a circular discharge pipe, the (b) pipe
diameter and (c) depth of bottom invert below
the water surface (water surface to bottom edge
of pipe) must be specified, respectively. In all
cases, CORMIX3 assumes the discharge is being
issued horizontally.
CORMIX3 uses the variable HDO for the
actual water depth just in front of the channel exit
and requires an additional specification for the
receiving water bottom slope, again in front of the
exit, extending into the receiving water body.
These details are important for identifying cases
where plume attachment to the bottom can occur.
In the case of a circular pipe discharge
CORMIX3 assumes the outlet is flowing full and
that it is not submerged under the water surface
by more than 1/4 of the outlet diameter. If the
discharge outlet has an odd cross-sectional
shape (e.g. a pipe flowing partially full) then it
should be represented schematically as a
rectangular outlet of the same cross-sectional
area and similar channel depth.
For open channel discharges,
considerable care should be exercised when
specifying discharge channel depth since this
parameter is directly linked to the ambient
receiving water depth (stage). This is especially
important for tidal situations.
To prevent an inappropriate system
application, CORMIX3 only allows for a discharge
channel depth-to-width aspect ratio of 0.05 to 5.
This prohibits the use of extremely oblong
discharge geometry.
4.6.2 Discharge Flow
For discharge characteristics, CORMIX3
requires the specification of 3 data entries. These
specifications include: (a) the total discharge
flow rate (Q0) or discharge velocity (U0), (b) the
discharge density or discharge temperature for
an essentially freshwater discharge, and (c) the
discharge concentration of the material of
interest. The Q0 and U0 variables are related
through the channel cross-sectional area; the
program computes and displays the alternate
value allowing for user inspection and verification.
The discharge concentration of the
material of interest (pollutant, tracer, or
temperature) is defined as the excess
concentration above anv ambient concentration of
that same material. The user can specify this
quantity in any units. CORMIX1 predictions
should be interpreted as computed excess
concentrations in these same units. If no specific
pollutant is under consideration, simply specify a
discharge concentration of 100%.
4.7 Pollutant Data
CORMIX allows three types of pollutant
discharges:
(a) Conservative Pollutant:
The pollutant does not undergo any decay/growth
processes.
(b) Non-conservative Pollutant:
The pollutant undergoes a first order decay or
growth process. One needs to specify the
coefficient of decay (positive number) or
growth (negative number) in units: /day (per day).
(c) Heated Discharge:
The discharge will experience heat loss to the
atmosphere in cases where the plume contacts
the water surface. It is necessary to specify the
discharge condition in terms of excess
temperature ("delta T") above ambient in units
degC, and the surface heat exchange
coefficient in units W/m2,degC. Values of the
heat exchange coefficient depend on ambient
water temperature and wind speed. The following
listing provides a guideline for the selection.
Typically, the near-field behavior is quite
insensitive to the choice of these values, but it
may affect the prediction results at greater
distances in the far-field.
The discharge concentration (CO) of the
material of interest (pollutant, tracer, or
temperature) is defined as the excess
concentration above anv ambient background
concentration of that same material. The user
can specify this quantity in any units of
concentration (e.g. mg/l, ppm, %, °C). CORMIX
predictions should be interpreted as computed
excess concentrations in these same units.
43
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SURFACE HEAT EXCHANGE COEFFICIENT (W/m2,°C)
Values for a lightly heated, natural water surface
(local excess temperatures 0 to 3 °C)
Ambient Water Wind Speed (m/s)
(°C)
0
1
2
4
6
8
5
5
10
14
24
33
42
10
5
11
16
27
38
49
15
5
12
18
31
44
59
20
5
14
21
38
52
68
25
6
16
25
45
63
82
30
6
19
30
54
76
100
Ref: "Heat Disposal in the Water Environment", E.E. Adams, D.R.F. Harleman, G.H. Jirka, and
K.D. Stolzenbach, Course Notes, R.M. Parsons Laboratory, Mass. Inst, of Techn., 1981.
If no pollutant data at all is available, it is
most convenient to specify CO = 100 %.
In case of an ambient background
concentration it is important to treat all pollutant
related data items in a consistent fashion. This
includes the specification of any regulatory values
as discussed in Section 4.8 below.
Example: suppose the actual discharge
concentration for a particular pollutant is
100 mg/l, and values of CMC and CCC for
the pollutant are 20 mg/l and 10 mg/l,
respectively. If the background ambient
concentration for the same pollutant is 4
mg/l, the data entry to CORMIX would be
for the discharge concentration = 96 mg/l,
for CMC =16 mg/l, and for CCC = 6 mg/l,
respectively. All concentration values
listed in the diverse CORMIX output (see
Chapter V) must then be interpreted
accordingly, and the actual concentration
values are computed by adding the
background concentration value. E.g. if
the CORMIX predicted value for one
particular point happens to be 13.6 mg/l,
then the total concentration value at that
point would be 17.6 mg/l. Also, all
program mixing zone messages would
occur at correct regulatory concentrations
because they are interpreted as excess
plume concentrations above ambient.
4.8 Mixing Zone Data
The user must indicate: (a) whether EPA's
toxic dilution zone (TDZ) definitions apply, (b)
whether an ambient water quality standard exists,
(c) whether a regulatory mixing zone (RMZ)
definition exists, (d) the spatial region of interest
(ROI) over which information is desired, and (e)
number of locations (i.e. "grid intervals") in the
ROI to display output details. Depending on the
responses to the above, several additional data
entries may be necessary as described in the
following paragraphs.
When TDZ definitions apply, the user
must also indicate the criterion maximum
concentration (CMC) and criterion continuous
concentration (CCC) which are intended to
protect aquatic life from acute and chronic effects,
respectively. CORMIX will check for compliance
with: (a) the CMC standard at the edge of the
TDZ and (b) the CMC standard at the edge of the
RMZ, proving a RMZ was defined. See
Subsection 2.2.2 for additional discussion.
44
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When a RMZ definition exists, it can be
specified by: (a) a distance from the discharge
location, (b) the cross-sectional area occupied by
the plume, or (c) the width of the effluent plume.
The ROI, which is a user defined region
where mixing conditions are to be analyzed, is
specified as the maximum analysis distance in the
direction of mixed effluent flow. The level of detail
for the output data within the ROI and thus, for the
entire hydraulic simulation, is established by
specifying the number of grid intervals that will be
displayed in the output files. This parameter's
allowable range is 3 to 50 and the chosen value
does not affect the accuracy of the CORMIX
prediction, only the amount of output detail. A low
value should be specified for initial calculations to
minimize printout lengths while a large value
might be desirable for final predictions to give
enough resolution for plotting of plume
dimensions.
4.9 Units of Measure
CORMIX uses the metric system of
measurement. When data values are provided to
the user in English units, these must be converted
to equivalent metric measures. The list at the
beginning of this manual gives the five metric
dimensions used by CORMIX in the left column,
and on the right, their equivalents in some
common English units.
Pollutant concentrations can be entered in
any conventional measure such as mg/L, ppb,
bacteria-count, etc.
Considering the potential accuracy of
CORMIX predictions, 3 to 4 significant digits are
sufficiently accurate for most input data values as
suggested in the above conversion list. The only
exceptions are the ambient and effluent density
values. These may require 5 significant digits,
especially when simulating the discharge to an
ambient density-stratified receiving water body.
45
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&
46
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V CORMIX Output Features
CORMIX is a highly interactive system and
conveys information to the user through
qualitative descriptions and detailed quantitative
numerical predictions. This output can be viewed
on-screen in text mode or graphics mode, can be
directed to a printer, and is stored in subdirectory
CORMIX\SIM and CORMIX\SIM\CXn files. In
this chapter the label n = 1, 2 or 3 designates the
appropriate CORMIX subsystem.
5.1 Qualitative Output: Flow Descriptions
After completion of the input data entry
sequences, the system proceeds through the
program elements following the flow chart
displayed in Figure 3.1. In addition to the routine
operational messages provided during program
execution, important qualitative information is
displayed on-screen about the ongoing analysis
of the given ambient/discharge case. The three
general types of descriptive information provided
are: (a) descriptive messages, (b) length scale
computation results and (c) flow class
descriptions. The paragraphs within this Section
aid in the interpretation of that information.
The program elements PARAM and
CLASS, in particular, provide essential
information on the expected dynamic behavior of
the discharge. By actively participating in the
interactive process, the novice and intermediate
user can derive a substantial educational benefit
and a technical appreciation of the physical
aspects of initial mixing processes. Although
advanced users may find some of the presented
material somewhat repetitive, they should still
consult the length scale computation results.
5.1.1 Descriptive Messages
These messages provide both physical
information and insight into the logic reasoning
employed by CORMIX. Three example
descriptive messages are:
"The effluent density (1004.5 kg/m^3) is greater than the surrounding
water density at the discharge level (997.2 kg/m^3).
Therefore, the effluent is negatively buoyant and will tend to sink
towards the bottom."
"STRONG BANK INTERACTION will occur for this perpendicular diffuser
type due to its proximity to the bank (shoreline). The shoreline will
act as a symmetry line for the diffuser flow field.
The diffuser length and total flow variables are doubled (or
approximately doubled, depending on the vicinity to the shoreline).
All of the following length scales are computed on that basis."
"The specified two layer ambient density stratification is dynamically
important. The discharge near field flow will be confined to the lower
layer by the ambient density stratification.
Furthermore, it may be trapped below the ambient density jump at the
pycnocline."
The preceding example output highlights
several features of CORMIX's descriptive
messages. These include: (a) conveying basic
information about the involved mixing processes,
(b) using a careful terminology (e.g. "..tend to
sink.."), (c) describing key calculation
assumptions, and (d) alerting the user to sensitive
analysis conditions. In some instances, the
provided information may be obvious to the user,
while in others it may not, particularly for
situations involving linear ambient stratification.
The use of a careful terminology is necessary
because messages are presented as the analysis
proceeds and subsequent tests may alter, or
47
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amplify, initial results. For example, near-field
instabilities, which are tested for late in the
analysis, can prevent an otherwise sinking plume.
5.1.2 Length Scale Computations
The program element PARAM computes
so-called "length scales" which represent
important dynamic measures about the relative
influence of certain hydrodynamic processes on
effluent mixing. These calculated values are
subsequently used in program element CI_ASS to
identify the generic flow class upon which the
hydraulic simulations will be based. This flow
classification is accomplished through formal
dynamic length scale analysis, which is a key
aspect of the theoretical underpinnings for the
CORMIX approach. The CORMIXdocumentation
manuals (5,6,7) and related journal publications
provide the theoretical background on length
scale definitions and significance, their derivation
from principles of dimensional analysis, and their
use in the CORMIX flow classification approach.
Although flow classification is a formal
process using criteria derived from theoretical
studies and/or experimental data, a great deal
can be deduced about the flow dynamics by
comparing the calculated length scales to the
actual physical measures of the
ambient/discharge situation. Of greatest
importance are comparison to such geometric
measures as: the available water depth (HD), a
pycnocline height (HINT) and the distance to the
nearest bank (DISTB). The following discussion
provides a brief explanation of the more important
length scales and examples on how to make
appropriate comparisons in a given application.
Users are encouraged to make these
comparisons.
a) Single port discharges: Some
important length scales relating to submerged
round buoyant jets (CORMIX1) are described in
Table 5.1. All of these scales are defined from
an interplay of the momentum and buoyancy flux
quantities of the discharge with each other or with
the current velocity and stratification gradient
variables.
As an example, consider a vertically
discharging buoyant jet into an unstratified
ambient receiving water. When both calculated
Lm and l^ values are substantially less than the
local water depth (HD), this is an immediate
indication to the user that the crossflow is very
strong, leading to complete bending of the
buoyant jet. If the reverse holds true, the
crossflow may be so weak that its deflecting effect
is negligible, and the buoyant jet will strongly
interact (impinge) with the water surface. In the
first instance, a situation as depicted in Figures
2.1b combined with Figure 2.1a will result, while
in the second instance, a flow resembling Figures
2.2c or 2.2d may arise, depending on the relation
of the two scales with each other.
As another example, consider a buoyant
jet discharging into a linearly stratified ambient. If
both Lm' and L*,' both larger than the pycnocline
height (HINT) and even the water depth (HA), this
would be an indication that the existing stratifi-
cation is so weak that it will not lead to any
trapping of the effluent plume within the available
vertical space.
By making such comparisons, users will
gradually get a good feel for the behavior of the
buoyant jet, and other mixing processes within the
space constraints of the ambient environment.
Those interested in design can quickly gain an
appreciation of the length scale measures and
their sensitivity to design choices. However, there
are limitations to these simplistic comparisons
because the "length scales" are bv no means
precise measurements for the influence of the
different processes. As their name implies they
should be taken only as "scale" estimates. The
actual CORMIX classification scheme uses formal
criteria when comparing the length scale
measures with the geometric constraints or each
other.
b) Multiport diffusers: Some important
length scales for multiport diffusers (CORMIX2)
are described in Table 5.2.
To a large extent, these scales have a
similar meaning for the behavior of the plane
buoyant jet as the earlier ones discussed for the
round buoyant jet (Table 5.1). However, they are
calculated differently because the CORMIX2
system uses the "equivalent slot diffuser" concept
to model the overall dynamics of the submerged
multiport diffuser (Section 3.1). Except for the
immediate close-up zone before the individual jets
merge (Figure 2.1d) this concept is a dynamically
valid and accurate representation of multiport
diffuser flows (6).
48
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Table 5.1
Length Scales for Single Port Submerged Discharges
(Used in C0RMIX1 and C0RMIX2)
Jet/plume transition length scale LM = M03 4 / J012
interpretation: For combined buoyant jet flow, the distance at which the transition from
jet to plume behavior takes place in a stagnant uniform ambient.
Jet/crossflow length scale Lm = M01/2 / ua
interpretation: In the presence of a crossflow, the distance of the transverse (i.e. across
ambient flow) jet penetration beyond which the jet is strongly deflected (advected) by the
cross flow. For a strictly co-flowing discharge (0 = 0, o = 0), the length of the region
beyond which the flow is simply advected.
Plume/crossflow length scale Lb = J0 / ua3
interpretation: The vertically upward or downward flotation distance beyond which a
plume becomes strongly advected by crossflow.
Jet/stratification length scale Lm' = M01/4 / e14
interpretation: In a stagnant linearly stratified ambient, the distance at which a jet
becomes strongly affected by the stratification, leading to terminal layer formation with
horizontally spreading flows.
Plume/stratification length scale Lb' = J014 / e38
interpretation: In a stagnant linearly stratified ambient, the distance at which a plume
becomes strongly affected by the stratification, leading to terminal layer formation with
horizontally spreading flows.
Notes: M0 = U0Q0, kinematic momentum flux
J0 = g'0Q0, kinematic buoyancy flux
Q0 = U0a0, source discharge volume flux
a0 = port area
ua = ambient velocity
U0 = port discharge velocity
e = ambient buoyancy gradient
g'0 = discharge buoyancy = g(pa - p0)/pa
However, there are some exceptions and
additional complexities to interpreting the two-
dimensional slot length scales measures
described in Table 5.2. In addition to the
predominately two-dimensional flow behavior,
some of the large scale dynamics of multiport
diffusers may also be influenced by other scales
depending on the overall diffuser flow pattern. A
notable example is circulating motions induced in
shallow receiving waters due to intermediate-field
effects (Section 2.1.1). The immediate close-up
zone before the individual jets merge is also not
addressed by the two-dimensional length scales.
Additional discussion of these and other
peculiarities can be found elsewhere (6,18).
49
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Table 5.2
Dynamic Length Scales for Multiport Diffuser (C0RMIX2) in the
Two-Dimensional "Slot" Discharge Representation
Slot jet/plume transition length scale fM = m0 /j02 3
interpretation: For combined buoyant jet flow, the distance at which the transition from
jet to plume behavior takes place in a stagnant uniform ambient.
Slot jet/crossflow length scale fm = m0 / ua2
interpretation: In the presence of a crossflow, the distance of the transverse (i.e. across
ambient flow) jet penetration beyond which the jet is strongly deflected (advected) by the
cross flow. For a strictly co-flowing discharge (0 = 0, o = 0), the length of the region
beyond which the flow is simply advected.
Slot jet/stratification length scale fm' = m013 / e13
interpretation: In a stagnant linearly stratified ambient, the distance at which a jet
becomes strongly affected by the stratification, leading to terminal layer formation with
horizontally spreading flows.
Slot plume/stratification length scale fb' = j013 / e12
interpretation: In a stagnant linearly stratified ambient, the distance at which a plume
becomes strongly affected by the stratification, leading to terminal layer formation with
horizontally spreading flows.
Crossflow/stratification length scale fa = ua / e12
interpretation: The vertically upward or downward floatation distance beyond which a
plume becomes strongly advected by crossflow.
Notes: m0 = U0q0, kinematic momentum flux per unit length
j0 = Q'cAf kinematic buoyancy flux per unit length
q0 = U0na0/LD, source discharge volume flux
a0 = port area
ua = ambient velocity
U0 = port discharge velocity
e = ambient buoyancy gradient
g'0 = discharge buoyancy = g(pa - p0)/pa
n = total number of nozzles
l_D = overall diffuser length
c) Buoyant surface jets: Some
important length scales that describe the near-
field dynamics of buoyant surface jets discharging
into unstratified receiving waters (CORMIX3) are
listed in Table 5.3. These scales are defined in a
similar manner to the submerged discharged
cases but due to the discharge location at the
surface, they have different interpretations. For
example, Lm is compared to the channel width
(BS) instead of the local water depth as it was in
submerged case examples; if it exceeds BS, the
discharge will quickly interact with the opposing
bank.
50
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Table 5.3
Dynamic Length Scales for Buoyant Surface Jets (C0RMIX3)
Discharging into Unstratified Receiving Water
Jet/plume transition length scale LM = M03/4 / J01/2
interpretation: For stagnant ambient conditions, the extent of the initial jet region before
mixing changes over into an unsteady surface spreading motion.
Jet/crossflow length scale Lm = M01/2 / ua
interpretation: The distance over which a discharging jet intrudes into the ambient cross-
flow before it gets strongly deflected.
Plume/crossflow length scale Lb = J0 / ua3
interpretation: A measure of the tendency for upstream intrusion for a strongly buoyant
discharge.
Notes: M0 = U0Q0, kinematic momentum flux
J0 = g'0U0, kinematic buoyancy flux
Q0 = U0a0, source discharge volume flux
a0 = channel cross-sectional area
ua = ambient velocity
U0 = channel discharge velocity
g'0 = discharge buoyancy = g(pa - p0)/pa
d) Tidal reversing flows: Additional
length and time scales can be defined for
unsteady flows in which the scale of influence of
oscillating plume depends on the rate of velocity
reversal change at slack tide (8,17). CORMIXwill
take the actual steady-state predictions and
adjust their concentration values according to the
time after reversal relative to the time scale Tu and
also limit their areal applicability relative to Lu.
5.1.3 Description of Flow Classes
Program element CI_ASS, performs a
rigorous classification of the given
discharge/ambient situation into one of many
generic flow classes with distinct hydrodynamic
features. In a way, this amounts to identifying a
general pictorial description of the expected flow
configuration.
Table 5.5 lists and describes the broad
categories of flow classes available in CORMIX.
CORMIX1, 2 and 3, consider 35, 31 and 11
distinct flow classifications, respectively. Each
flow class identification consists of an
alphanumeric label corresponding to the flow
category and a number (e.g. MU2). Text
descriptions of the flow classes are available on-
screen during the analysis and can printed from
the files stored within sub-directory
CORMIXYTEXT (Table 3.1). Pictorial illustrations
of the flow classes can be found in Appendix A.
As an example, Figure 5.1 shows the pictorial
illustration and text description for flow class S1,
a case of an effluent that becomes trapped in
ambient stratification. It is strongly recommended
that novice or intermediate users scrutinize these
materials to gain a qualitative understanding of
the effluent flow's behavior.
51
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Table 5.4
Dynamic Length and Time Scales for
Discharges into Unsteady Tidal Reversing Flows
Jet-to unsteady-crossflow length scale Lu
M0
diL/dt
1/3
interpretation: A measure of the distance of the forward propagation into the ambient
flow of a discharge during the reversal episode.
Jet-to unsteady-crossflow time scale Tu
M,
du_/dt
a
11/4
1/6
interpretation: a measure of the duration over which an effluent may be considered as
discharging into stagnant water while the velocity field is reversing.
Notes: M0 = U0Q0, kinematic momentum flux
|dua/dt| = time rate of reversal of ambient velocity (absolute value)
Table 5.5
Flow Class Categories and Descriptions
CORMIX1:
35 flow classes
Classes S:
Classes V,H:
Classes NV,NH:
Classes A:
CORMIX2 :
Classes MS:
Classes MU:
Classes MNU:
CORMIX3
Classes FJ:
Classes SA:
Flows trapped in a layer within linear stratification.
Positively buoyant flows in a uniform density layer.
Negatively buoyant flows in uniform density layer.
Flows affected by dynamic bottom attachment.
31 flow classes
Flows trapped in a layer within linear ambient stratification.
Positively buoyant flows in a uniform density layer.
Negatively buoyant flows in uniform density layer.
9 flow classes
Free jet flows without near-field shoreline interaction.
Shoreline-attached discharges in crossflow.
52
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Classes WJ:
Classes PL:
Wall jets/plumes from discharges parallel to shoreline.
Upstream intruding plumes.
FLOW CLASS SI
This flow configuration is profoundly affected by the linear
ambient density stratification. The predominantly jet-like flow
gets trapped at some terminal (equilibrium) level. The trapping
is also affected by the reasonably strong ambient crossflow.
Following the trapping zone, the discharge flow forms an internal
layer that is further influenced by buoyant spreading and passive
diffusion.
The following flow zones exist:
1) Weakly deflected jet in crossflow: The flow is initially
dominated by the effluent momentum (jet-like) and is weakly
deflected by the ambient current.
2) Strongly deflected jet in crossflow: The jet has become strongly
deflected by the ambient current and is slowly rising toward the
trapping level.
3) Terminal layer approach: The bent-over submerged jet/plume
approaches the terminal level. Within a short distance the
concentration distribution becomes relatively uniform across the
plume width and thickness.
*** The zones listed above constitute the NEAR-FIELD REGION
in which strong initial mixing takes place. ***
4) Buoyant spreading in internal layer: The discharge flow within
the internal layer spreads laterally while it is being advected by
the ambient current. The plume thickness may decrease during this
phase. The mixing rate is relatively small. The plume may interact
with a nearby bank or shoreline.
5) Passive ambient mixing: After some distance the background
turbulence in the ambient shear flow becomes the dominating mixing
mechanism. The passive plume is growing in depth and in width. The
plume may interact with the upper layer boundary, channel bottom
and/or banks.
*** Predictions will be terminated in zone 4 or 5 depending on
the definitions of the REGULATORY MIXING ZONE or the REGION OF
INTEREST. ***
Figure 5.1: Example of a Flow Class Description
53
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5.2 Quantitative Output: Numerical Flow
Predictions
After execution of the detailed flow
prediction in program element HYDROn, the
system provides two types of detailed numerical
output on effluent plume trajectory and mixing and
on compliance with regulations. A concise
summary is available on-screen in the final
system element SUM and a detailed numerical
output file is also generated for inspecting and
plotting the plume's behavior after the analysis.
5.2.1 Summary Output in SUM
The self-explanatory summary output
which can be displayed on-screen includes: (a)
the date and time of the analysis section, (b) a
complete echo of the input data, (c) the calculated
flux, length scale and non-dimensional parameter
values, (d) the flow classification used for
predicting plume trajectory and mixing, (e) the
coordinate system used in the analysis, (f) a
summary of the near-field region (NFR)
conditions, (g) the far-field locations where the
plume becomes essentially fully mixed (i.e.
uniform concentration) in the horizontal and
vertical directions, (h) a summary of the toxic
dilution zone (TDZ) conditions, and (I) a summary
of the regulatory mixing zone (RMZ) conditions.
Although the raw data used to construct this
summary output is permanently stored in file
'fn'.CXC within the output sub-directory
CORMIX\SIM\CXn, a hard-copy printout should
be requested during the analysis session because
the raw data file is unformatted and does not
contain the explanatory text that is available
during program execution; 'fn' is the filename
specified by the user during input data entry.
The coordinate system conventions
pertain to the origin location and axis direction. In
CORMIX1 analyses, the origin is located at the
bottom of the receiving water just below the
discharge port center and thus, at a depth HD
below the water surface. In CORMIX2 analyses,
the origin is located at the bottom of the receiving
water, at the midpoint of the diffuser line and thus,
at a depth HD below the water surface. In
CORMIX3 analyses, the origin is located at the
water surface where the discharge channel
centerline and receiving water shoreline intersect.
The x-axis lies in the horizontal plane and points
downstream in the direction following the ambient
flow; the y-axis lies in the horizontal plane and
points to the left as seen by an observer looking
downstream along the x-axis; and the z-axis
points vertically upward. Note that when the
ambient current direction varies (e.g. due to
reversing tidal flows), the interpretation of
simulation results becomes more involved since
the x-axis and the y-axis will change depending
on flow direction.
In addition to the numerical predictions of
the plume size, location and chemical
concentration, the summary of the near-field
region (NFR) conditions describes other relevant
plume features such as bottom attachment, bank
interaction and the degree of upstream intrusion.
This information is useful for both engineering
design and for determining whether important
resource areas may be exposed to undesirable
chemical concentrations.
In case of a toxic discharge, the summary
toxic dilution zone (TDZ) conditions will indicate
the location along the plume where the local
concentration begins to fall below the specified
CMC. CORMIX automatically checks compliance
with the three geometric restrictions listed for
mixing zones associated with toxics discharges
under alternative 3 (see Subsection 2.3.3) and the
results of these comparisons are displayed. The
user can evaluate the fourth alternative by
referring to travel times given at the end of each
simulation module in the related output files.
When regulatory mixing zone (RMZ)
criteria have been specified during input data
entry, the geometric, dilution and concentration
conditions at the edge of the specified or
proposed RMZ are compared to these criteria
and/or to the applicable CCC concentration
following the practices discussed in Subsection
2.2.4. The results of these comparisons are
displayed.
5.2.2 Detailed Prediction Output File/h'.CXn
The file 'fn'.CXn stored within sub-directory
CORMIX\SIM contains the same kinds of
information available in the summary output plus
the detailed numerical predictions on plume
geometry and mixing produced during the
hydraulic simulation. Data in that file forms the
54
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basis for further analysis, inspection, evaluation,
and plotting of the plume shape and trajectory.
The graphics package also uses the same data to
plot on-screen, and print if desired, the plume
properties as explained in Section 5.2.3.
During program execution, the user has
several opportunities to display on-screen or print
out this file. It can also be printed at a later date
by using the DOS PRINT command or any word
processor. CORMIX will not erase any of the files
with .CXn (or .CXC) extension that get stored in
the CORMIX\SIM sub-directory. Consequently,
periodic directory maintenance is recommended
to remove old and superfluous files. This is best
accomplished with a built-in file manager (see
Main Menu) that deletes the specified files from
the hard disk, but also erases their entry from the
record keeping file CORMIX\SIM\CXn\summary.
The 'fn'.CXn file is a FORTRAN output file
generated by the HYDROn prediction program.
As is typical of many FORTRAN outputs, its
display features are terse with tight format control
and data items labeled in symbolic form only (e.g.
"QO" for discharge flow rate). Complete output file
examples can be inspected in Appendices B, C
and D.
All three CORMIXn subsystems produce
a 'fn'.CXn output file with common appearance
and features as described in the following
paragraphs.
a) Lead-in information: The output starts (and
ends) with a "111...111", "222...222", or
"333...333" banner line to accentuate which
subsystem has been used. The date and time of
the analysis session and all important input data
are the next items in the file. These are
subsequently followed by the calculated length
scale values, non-dimensional numbers of
interest to the specialist, the flow class
identification, and the coordinate system is
displayed.
b) Prediction results for each flow "module":
As was mentioned previously in Subsection 3.6,
the CORMIX prediction methodology utilizes a
number of simulation modules that are executed
sequentially and that correspond to the different
flow processes and associated spatial regions
which occur within a given flow class. The
'fn".CXn output reflects that sequence and is a
arranged in output blocks for each module.
Each simulation module has a "MODnxx"
label where "n" is 1, 2, or 3 corresponding to
CORMIXn, and "xx" is a two-digit identification
number. The two general types of modules are
continuous flow and control volume.
The continuous flow module type
describes the continuous evolution of a flow
region along a trajectory. Depending on the
number of grid intervals specified by the user,
information on plume geometry, flow, and mixing
information along the plume trajectory may be
available for a few or many water body locations.
Figure 5.2 provides examples of typical
output from continuous flow modules. The
annotations along the right margin illustrate
important features of the output format.
Figure 5.2a was taken from a CORMIX1
simulation output file and shows an example of a
submerged jet region module (MOD110,
equivalent to CORJET). The output contains
labeling information on the module, and
explanatory notes on profile definitions. It also
gives a numerical list on the predictions, first
repeating the final values from the preceding flow
module and then one line for each user-specified
grid interval. This information gives the x-y-z
position of the jet/plume centerline, the dilution (S)
and concentration (C) at the centerline, and the
jet width (B).
Dilution (S) is defined as the ratio of the
initial concentration (at the discharge port) to the
concentration at a given location, irrespective of
any decay or growth effects if specified for a non-
conservative pollutant. However, concentration
(C) will include any first-order effects for non-
conservative pollutants. Dilution (S) given by
CORMIX for submerged jet or plume regions is
the minimum centerline dilution for the jet/plume.
The control volume and buoyant spreading
modules give bulk dilutions, which are equivalent
to flux-averaged dilutions for these regions. If a
flux-averaged dilution Sf is desired for submerged
jet or plume regions, the ratio of flux-average to
minimum centerline dilution Sf/S = 1.7 and 1.3,
for single-port round and multiport plane
discharges, respectively.
55
-------
BI] PT CORJET (MOD110) : JET/PLUME NEAR-FIELD MIXING REGION
Jet/plume transition motion in weak crossflow.
Zone of flow establishment: THETAE= 0.00 SIGMAE = 277.06
LE = 3.39 XE = 0.21 YE = -3.38 ZE = 1.00
Profile definitions:
B = Gaussian 1/e (37%) half-width, normal to trajectory
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
X Y Z S C B
0.00 0.00 1.00 1.0 0.100E+03 0.76
0.21 -3.38 1.00 1.0 0.100E+03 0.76
0.90 -7.41 4.11 1.8 0.562E+02 1.13
1.55 -9.36 9.07 3.3 0.300E+02 1.59
2.23 -10.55 14.27 5.4 0.186E+02 2.10
2.95 -11.39 19.56 7.9 0.127E+02 2.63
3.72 -12.02 24.85 10.8 0.928E+01 3.16
Cumulative travel time = 18. sec
END OF CORJET (MOD110): JET/PLUME NEAR-FIELD MIXING REGION
a) Submerged buoyant jet module
BUOYANT AMBIENT SPREADING
BV = top-hat thickness, measured vertically
BH = top-hat half-width, measured horizontally from bank/shoreline
S = hydrodynamic average (bulk) dilution
C = average (bulk) concentration (includes reaction effects, if any)
Plume Stage 1 (not bank attached):
BEGIN
Profile definitions:
X
Y
Z
s
C
BV
BH
1 . 93
- . 82
o
o
o
CO
. 884E+00
. 03
. 58
2 . 07
- . 82
o
o
o
8 . 5
. 869E+00
. 03
. 62
2 .20
- . 82
o
o
o
CO
. 856E+00
. 03
.65
** WATER QUALITY STANDARD OR CCC HAS BEEN FOUND **
The pollutant concentration in the plume falls below water quality standard
or CCC value of .850E+00 in the current prediction interval.
This is the spatial extent of concentrations exceeding the water quality
standard or CCC value.
2 . 34
- . 82
0
00
CO
CO
. 844E+00
. 03
.68
CO
- . 82
0
00
8 . 9
. 833E+00
. 03
. 71
2 . 62
- . 82
0
00
9 . 0
. 822E+00
. 03
. 74
2 . 76
- . 82
0
00
9 .1
. 811E+00
. 03
. 77
2 .89
- . 82
0
00
9.2
. 801E+00
. 03
.80
2 . 96
- . 82
0
00
9 . 3
. 796E+00
. 03
. 82
Cumulative travel time =
95. sec
to LEFT bank/shore.
Plume width is now determined from LEFT bank/shore.
Plume Stage 2 (bank attached):
Plume is ATTACHED
X
Y
Z
s
C
BV
BH
2 . 96
.00
0
.00
9 . 3
. 796E+00
. 03
. 82
16 . 05
.00
0
.00
31 . 3
.237E+00
. 03
2 .59
29 .13
.00
0
.00
96 . 8
. 764E-01
. 06
3 . 77
42 .22
.00
0
.00
220 . 7
. 335E-01
.10
4 . 76
55 .31
.00
0
.00
411 .4
.180E-01
. 16
5 . 64
68 .39
.00
0
.00
675 . 3
.110E-01
.23
6 .45
81.48
.00
0
.00
1017 . 8
. 727E-02
.31
7.20
94 . 56
.00
0
.00
1443 . 5
. 513E-02
.40
7 . 91
101 .11
.00
0
.00
1688 . 9
. 438E-02
.45
8 .26
iulative
travel
time
=
3367
. sec
b) Far-field flow module (example of buoyant spreading with bank contact)
Figure 5.2: Examples of continuous flow modules within CORMIX
56
-------
The cumulative travel time (T) is given at
the end of each simulation module. The travel
time can be used to assess the applicability of the
steady-state predictions given by CORMIXto time
scales appropriate for the particular application.
Another example of a continuous flow
module output is shown in Figure 5.2b. It was
abstracted from a CORMIX simulation output file
and shows predictions for the far-field process of
buoyant ambient spreading (Figure 2.6).
Although it is terse, the output file values and
commentary generally provide a complete picture
of flow conditions. In this example output (Figure
5.2b), evidence of this completeness includes: (a)
the prediction output is separated in two stages
corresponding to before and after bank
interaction, respectively; due to the typical oblong
cross-section of the plume in this stage, width
dimensions for the vertical and lateral extent are
given and defined; the coordinates for the upper
and lower boundaries of the plume are listed as a
convenience for plotting; and the system
searches for criteria that apply to mixing zone
regulations and when a criterion is satisfied, a
remark gets inserted in the output list at the
appropriate spatial position. (Note: The length
dimensions in Figure 5.2b are small as they relate
to a laboratory simulation.)
Some mixing flow processes are so
complicated that no mechanistically-based
mathematical description of them is presently
available in state-of-the-art science. Those
processes are best analyzed with control
volume modules as shown in Figure 5.3.
In the control volume modeling approach, the
outflow values for a region are computed as a
function of the inflow values and are based on
conservation principles.
An output example for control volumes
modules is illustrated in Figure 5.3. It is taken
from a CORMIX1 simulation output file and gives
predictions for a flow case corresponding to an
unstable near-field (Figure 2.2c). Note that a
separate listing of inflow variables and outflow
variables is given with appropriate explanations.
The tabular listing of plume shape is based on an
interpolation routine using a generic plume shape
for these upstream intruding motions, rather than
a detailed computation.
c) Numerous other supplementary messages
on plume behavior (e.g. bottom attachment, bank
contact, etc.) and on possible model restrictions
(e.g. ambient dilution limitations in a flow-
restricted river) are contained in the output as
warranted; Figures 5.2 and 5.3 provide but a few
examples of these user aids.
5.3 Graphical Output: Display and Plotting of
Plume Features Using CMXGRAPH
5.3.1 Access to CMXGRAPH
CMXGRAPH is a specially developed
graphics package, written in C++, for the display
and plotting of CORMIX (and also CORJET, see
Section 6.2) predicted effluent plumes. It uses
the prediction files 'fn'.CXn that are stored in the
directory CORMIX\SIM, and plots plume features
based on the numerical and narrative information
contained in these files.
The graphics system can be accessed in
different ways:
(1) Use within CORMIX: Different access modes
exist here.
(1a) The user can display the plume
graphics immediately after the actual
prediction and before the file information
is stored. This is useful for an initial
inspection and evaluation of results.
(1 b) It can be accessed at an end of the
prediction after the file has been stored,
by entering the Post-Processor option in
the Iteration Menu.
(1c) It can be accessed on earlier existing
files by directly choosing the Post-
Processor option in the Main Menu.
(2) Use outside CORMIX:
The graphics system can be invoked
directly by typing:
cmxgraph (or simply: eg) filename
where filename (including path and
extension) is any prediction file generated
by CORMIX or by CORJET.
57
-------
BEGIN MOD13 2: LAYER BOUNDARY IMPINGEMENT/UPSTREAM SPREADING
Vertical angle of layer/boundary impingement = 79.65 deg
Horizontal angle of layer/boundary impingement = 324.93 deg
UPSTREAM INTRUSION PROPERTIES:
Upstream intrusion length = 328.95 m
X-position of upstream stagnation point = -325.23 m
Thickness in intrusion region = 0.55 m
Half-width at downstream end = 470.97 m
Thickness at downstream end = 0.70 m
In this case, the upstream INTRUSION IS VERY LARGE, exceeding 10 times
the local water depth.
This may be caused by a very small ambient velocity, perhaps in
combination with large discharge buoyancy.
Control volume inflow:
X
3 . 72
Y
-12.02
Z
24 . 85
S C
10.8 0 . 928E+01
B
3 .16
Profile definitions:
BV = top-hat thickness, measured vertically
BH = top-hat half-width, measured horizontally in Y-direction
ZU = upper plume boundary (Z-coordinate)
ZL = lower plume boundary (Z-coordinate)
S = hydrodynamic average (bulk) dilution
C = average (bulk) concentration (includes reaction effects, if any)
X
-325.23
-313.94
-258.63
-203 .31
-148 .00
-92 . 68
-37.37
17 .95
73 .26
128.58
183 .89
239.21
Cumulative
Y
-12.02
-12.02
-12.02
-12.02
-12.02
-12.02
-12.02
-12.02
-12.02
-12.02
-12.02
-12.02
travel ti
Z
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
me =
S
9999 . 9
46 . 5
19 .3
14 . 5
12 . 5
11 .4
10 . 9
11 . 0
14 .4
19 .1
22 . 0
23 .2
3037 .
C
000E+00
215E+01
519E+01
688E+01
802E+01
878E+01
919E+01
913E+01
694E+01
522E+01
455E+01
431E+01
sec
BV
0 .00
0 .13
0.31
0.40
0.47
0 . 52
0 . 54
0 .55
0 .59
0.65
0.68
0 .70
BH
0 . 00
66.61
161.78
218.89
263.91
302 .30
336 . 34
367 . 24
395.73
422.30
447.30
470 . 97
ZU
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
28 . 00
ZL
28 . 00
27.87
27.69
27.60
27 . 53
27.48
27.46
27.45
27.41
27.35
27 . 32
27.30
END OF MODI32: LAYER BOUNDARY IMPINGEMENT/UPSTREAM SPREADING
Figure 5.3: Example of control volume flow module
58
-------
As mentioned, numerous flow features (as
evidenced by the different flow classes) can
occur. It is difficult to develop a robust graphics
package that operates safely for all of these
possibilities. The CMXGRAPH system has been
widely tested, but occasional crashes can occur
for rare flow module combinations and then only
for certain plot types. Should a crash occur and
the direct access mode (1a), listed above, has
been used then the current file information will be
lost. In those cases, it is safer to first save the
current session file data and then exercise the
graphics system.
5.3.2 Use of CMXGRAPH
The graphics system has a self-
explanatory screen interface as shown in Figure
5.4. The menu is controlled by the keyboard
alone by typing the letters that appear in capital
on the menu buttons, or by user the four cursor
keys when in zoom mode.
The GRAPHICS MENU COMMANDS are as follows:
Help an advice section is available listing the same information as given here
Quit exits the graphics system
There exist FIVE PLOT TYPES:
Plan generates a plan view of plume (x-y), as seen from above (entry option)
Side generates a side view of plume (x-z), as seen by an observer looking from the
bank/shore
Traj generates a side view along trajectory of plume. The view is stretched out along the
actually curving centerline trajectory.
c-X generates a plot of concentration on the plume centerline plotted against downstream
distance x
c-D generates a plot of concentration on the plume centerline plotted against distance along
the plume trajectory
The user can CONTROL the plume VIEW:
Near displays the near-field region only ; useful for close-up details (entry option)
Full displays the complete near- and far-field regions (i.e. the entire prediction results)
SHOW/HIDE FEATURES can be exercised to display additional information:
Labels puts identifier labels (site/case information) on top of plot (entry option)
Wqual displays information on regulatory mixing regulations (TDZ, RMZ,...) on the plot; this is
59
-------
displayed by dotted lines where particular regulations are encountered.
Module shows boundaries of prediction modules
ZOOM/SCALE CONTROL allows control of plot details:
Zoom allows the user to enlarge any RECTANGULAR SECTION of the current plot; this is
accomplished by:
- Use CURSOR Control keys to move cursor (up,down,left,right)
- Cursor SPEED can be modified by typing any number: 1 (slowest),2,.. to O(fastest)
- Press RETURN when first corner of desired rectangle has been reached
- Move cursor to find opposite corner and press RETURN to fix opposite corner
sKale allows the user to FIX SCALE distortion of current plot. The current scale is displayed
in a window on the menu bottom (see Figure 5.4).
- Type in desired distortion at the prompt: All subsequent versions of the plot (including
zooms will be fixed at this scale distortion.
- Use the sKale button again, to release the scale distortion.
Bkup back-up to earlier zoomed/scaled versions of current plot
Esc exit from zoom/scale mode (also Quit or repeated Bkup can be used to exit)
Several PRINT OPTIONS are available:
pflle writes the current plot to a POSTSCRIPT FILE for later printing. The file can be edited
and/or printed later using any compatible software (including public domain software,
such as Ghostscript).
- Each print file is stored as \"//7ename.Pvn\" where:
filename = CORMIX or CORJET assigned filename,
Pvn = file extension indicating a Postscript file,
v = P, S, T, X or D, for one of the five view types,
n = 0 to 9, increasing file number.
- If the total file number for a particular view type exceeds the maximum of ten (10), the
first file in the series will be erased and replaced by the new file.
psCrn allows a PRINT SCREEN action of the current plot
- The plot is first recreated without the menu interface and plot border.
- Then use the Shift-PrintScreen buttons, to print the plot on-line.
Important: The PRINTER must have been initialized for GRAPHICS MODE with the
DOS command: Y'graphics [type] /r\" where: [type] = type of printer (e.g.: color4,
laserjetii).
60
-------
DEEP-RESERUOIR
A-PLANT^SUMMER^STRATIFICATION
CORHIXi Prediction
File: sim\SAMPLEl . cxl
, £
>o-i
o_
>0
o
o
cs A
o-
0
001
o-
o
V
•111
'¦y*
Field
*****
500
**™V
1000
1500
"'"I"1
2000
Bank /shore, r i^qht
2500
Plan Uieu
3000 3500
X (m) —>
CORMIX Graph Menu
Zoom/Scale Control Shou/Hide
Plan
Full
Labpl
Print Options
Uqual P^le!
psCr n
Help
Distortion V:X = 0.808
Module
Qui t
-------
The case study materials in the
Appendices show some of the possibilities that
can be exercised in the graphics display the
plume features described in the fn.CXn output
files. As shown above, the plume is characterized
by its centerline trajectory, dilution, and width
values. For understanding added detail in the
plume cross-section, it is important to keep in
mind the different concentration distributions and
meanings of "plume width". These are explained
in the supplemental statements at the beginning
of each flow module (see Figures 5.2 and 5.3).
Also, Figure 5.5 may be useful for further
illustration. It gives the cross-sectional distribution
of concentration for many of the commonly
occurring plume cross-sections in the various
regions predicted by the CORMIXn subsystems.
In some instances, users may desire to
plot concentration isolines for the predicted plume
shapes. The information contained in the
HYDROn output file for each module and the
definitions shown in Figure 5.5 are sufficient to
construct such plots. In particular, in submerged
plume or passive mixing regions having a
Gaussian distribution, the following formula can
be used
c(n) = cce D
where c(n) is the lateral concentration, n is the
coordinate position measured tranversely away
from the centerline, cc is the centerline
concentration, e is the natural logarithm base, and
b is the local plume half-width. However, this
equation can not be used to plot concentration
isolines in the control volume or buoyant
spreading regions because they are defined with
a top-hat or uniform concentration profile and not
a Gaussian distribution.
By and large, all CORMIXn predictions are
continuous from module to module satisfying the
conservation of mass, momentum and energy
principles. Occasionally, some mismatches in
plume width can occur as a consequence of
enforcing these principles. Most of these will be
barely noticeable with the usual plotting resolution
and they can usually be safely ignored. Some of
the mismatches or discontinuities can be kept to
a minimum by specifying a large number for the
grid intervals (see Section 4.9) to increase the
resolution of the CORMIX prediction. This is
especially useful for the final simulations on a
particular design case.
In addition, when bottom attachment or
bank interaction occurs, the plume trajectory is
assumed to (and simulation predictions do) shift
suddenly to the boundary. In actuality, that shift
would be much more gradual and this should be
considered when interpreting the results of the
CMXGRAPH plots or, alternatively, when plotting
plume features by hand.
62
-------
Submerged
jet /plume
\
cc = center line
Gaussian
profile
a) Submerged round
jet/plume cross-section
B = radius
Q
S = centerline dilution = —
c,.
C
>.37cc
IP
m
/z////////'
'////W'///'/,
^Gc
lussian profile
uniform laterally
V
Uniform
concentration c
b) Submerged plane
jet/plume cross-section
BV = normal width
BH = lateral width
S = centerline dilution = —
c) Cross-section during
buoyant spreading along
water surface
BV = vertical width
BH = lateral width
c0
S = average dilution = —
Cc
0.46 cc
Gaussian profiles
0.46 cf
d) Cross-section during
ambient diffusion process
BV = vertical width
BH = lateral width c
S = centerline dilution = -p-
Figure 5.5: Cross-sectional distributions of CORMIX predicted jet/plume sections
63
-------
hi
64
-------
VI Post-Processor Models CORJET and FFLOCATR:
Input and Output Features
The CORMIX system contains three post-
processor options which be accessed directly
from within the system or independently outside of
CORMIX. In either case, the post-processor
options provide additional enhancements to
CORMIX in terms of plume display, and more
detailed computation of near- and far-field plume
features.
The first of the options, the graphics
package CMXGRAPH, has already been
described in Section 5.3. The second option is
CORJET, the Cornell Buoyant Jet Integral Model,
for the detailed analysis of the near-field behavior
of buoyant jets. FFLOCATR, the Far-Field
Plume Locator, for the far-field delineation of
discharge plumes in non-uniform river or estuary
environments is the third option. The latter two
are described in this chapter.
6.1 CORJET: The Cornell Buoyant Jet Integral
Model
6.1.1 General Features
CORJET is a Fortran model that solves
the three-dimensional jet integral equations for
submerged buoyant jets -either a single round
jet or interacting multiple jets in a multiport
diffuser- in a highly arbitrary ambient
environment. The ambient/discharge conditions
include an arbitrary discharge direction, positive,
neutral or negative discharge buoyancy, an
arbitrary stable density distribution, and a non-
uniform ambient velocity distribution with
magnitude and direction as a function of vertical
position.
Figure 6.1 displays these general
characteristics for the case of a single port. In
case of the multiport diffuser all the discharge
port/nozzles point in the same direction
(unidirectional or staged design) and the diffuser
line can have an arbitrary alignment angle relative
to the ambient current (for definitions see Section
4.5.1).
The detailed theoretical basis for CORJET
can be found in the documentation report (8) on
recent CORMIX system enhancements. CORJET
is a type of a jet integral model whose original
development in a two-dimensional framework and
for a round jet only was first reported in the peer-
reviewed literature by Jirka and Fong (25).
Detailed verification studies with various
experimental data sources have been reported
(8,26).
In jet integral models the hydrodynamic
equations governing the conservation of mass
and momentum, and of other quantities as
pollutant mass, density deficit, temperature and/or
salinity, are solved step-wise along the general
curved jet trajectory. The solution yields values of
the trajectory position itself and of the centerline
concentrations of these quantities, while the
actual cross-sectional distribution is fixed a priori
(mostly as a Gaussian distribution) in these
models. Literally several dozen such model
developments have been reported in the literature
over the last thirty years or so of research on
these mixing phenomena. Most of these
developments differ (I) in the degree of simplifying
assumptions on the ambient/discharge
characteristics (e.g. two-dimensional trajectories
or uniform ambient conditions only), and (ii) in the
type of closure that is made to specify the
turbulent growth and entrainment behavior in
these jets under a variety of forcing conditions.
Thus, some of these models can be
demonstrated to be unduly limited for practical
applications, and others to be clearly invalid in
certain limiting regimes of plume behavior.
Whenever a jet integral model is
reasonably general in its formulation and has
been validated through experimental data
comparison under a number of conditions it can
be considered a useful prediction tool for near-
field plume analysis. For practical purposes, all
the models that meet the above conditions, in
fact, differ little in their prediction results. The
deviation among model results is usually less
than the scatter in experimental data that is used
for their verification. This holds true also for
CORJET as well as another jet integral model,
65
-------
Figure 6.1: General three-dimensional trajectory of submerged buoyant jet in ambient flow with
arbitrary density and velocity distribution: Case of a single round jet
(27), that has current USEPA support and
distribution.
Both CORJET and PLUMES, although
they differ in their internal formulation and
closure assumptions, have a wide generality in
discharge/ambient conditions and a reasonable
verification base for a variety of conditions. They
can deal with three-dimensional trajectories, with
positive, neutral or negative discharge buoyancy,
with conditions of reversible buoyancy (so-called
nascent conditions in freshwater systems due to
the density maximum at 4°C, requiring use of the
full non-linear equation of state), with first-order
pollutant decay, with variable stable ambient
density, and with sheared non-uniform ambient
currents, and with the merging of multiple port
diffuser plumes. Three specialized features that
the PLUMES model cannot deal with are a
variable current direction at different levels,
arbitrary diffuser alignments (with the extreme of
a fully parallel alignment, y = 0° in Figure 4.6),
and applications to atmospheric plumes (using
the concept of potential temperature and
density).
Jet integral models, such as CORJET and
66
-------
PLUMES, appear as useful and efficient tools for
the rapid analysis of the near-field mixing of
aqueous discharges. They require fairly little
input data and are numerically efficient. However,
their inherent limitations must be kept in mind.
All jet integral models, including
CORJET, assume an infinite receiving water
body, without any boundary effects due to limiting
dimensions vertically (surface, bottom, or
pycnocline) or laterally (banks or shore). Thus,
they do not deal with such hydrodynamic effects
as jet attachment and near-field instabilities that
are so prevalent in many aqueous discharge
plumes as emphasized in Section 2.1.1.
Furthermore, they are near-field models only
and do not give predictions on what happens to
the entire mixing zone that may often cover larger
distances (see Section 2.2.5).
In summary, jet integral models if used
alone and by an inexperienced analyst are not a
safe methodology for mixing zone analysis.
They become safe only when used in conjunction
with a more comprehensive analysis using the full
CORMIX system. Therefore, in case of
engineering design applications, CORJET should
be employed after prior use of the expert
system CORMIX has indicated that the
buoyant jet will not experience any
instabilities due to shallow water or due to
attachment to boundaries.
In fact, the CORMIX system has built in
several safeguards and warning statements to the
user as explained below. When used in that
context CORJET becomes a highly useful
addition to the CORMIX system that can provide
considerable additional detail and sensitivity
analysis in the immediate near-field of the
discharge plume.
6.1.2 Access to CORJET
CORJET, like the other post-processor
options such as the graphics system (Section
5.3.1), can be accessed in different ways:
(1) Use within CORMIX:
(1a) It can be accessed at an end of the
prediction after the file has been stored,
by entering the Post-Processor option in
the Iteration Menu.
(1b) It can be accessed on earlier
existing files by directly choosing the Post-
Processor option in the Main Menu.
In either case, once the CORJET
option is chosen the user must first
specify whether a CORMIX1 or 2
simulation should be analyzed for the
near-field with CORJET. Then the
CORMIX1 or 2 filename in the
CORMIX\SIM directory must be specified.
CORJET will run automatically using the
input data of the given CORMIX data file.
(2) Use outside CORMIX:
CORJET can be invoked directly by
typing:
corjet (or simply: cj) filename
where filename (including path and
extension) is any specially prepared input
data file (see following section).
Alternatively if one types:
corjet (or simply: cj)
the model will prompt the user for the
input data filename.
6.1.3 CORJET Input Data File
This section for data preparation applies
only if CORJET is run independently from the
CORMIX system as discussed above. The
checklist given on the following page is useful
for data assembly prior to input data entry.
In this case, the Fortran model CORJET
reads input data file with filename that is user-
specified with arbitrary name, extension and
directory. For user convenience it is
recommended that all such files be kept in the
special directory CORMIX\POST\CJ.
The input data file is a Fortran-readable
file that is read in open format, that is all pertinent
data values are arranged on a line and separated
by one or more open spaces. The file consists of
five data blocks, each of which must be lead in by
two dummy lines that are not read. Table 6.1
gives an example of a data file in which the
dummy lines are indicated by the # sign.
67
-------
Table 6.1
Example of an input data file for CORJET
#CORJET INPUT FILE
#Title line (50 characters max.):
Case2: SINGLE PORT, STRATIFIED, VARIABLE CURRENT
#Fluid (l=water,2=air), Density option (l=calculate,2=specify directly):
#Fluid {y2) : Density option {y2) : Ambient levels (1-10) :
11 3
#Ambient conditions (if d.o.=l, fill in TA+SA; if 2, fill in RHOA):
#Level
ZA
TA
SA
RHOA
UA
TAUA
1
0 .
12 .
30 .
0 . 5
0 .
2
5 .
15 .
29.5
0 . 8
0 .
3
15 .
20 .
28 .
1.2
0 .
#Discharge conditions (T0+S0, or RHOO as above; if NOPEN=l: set LD=0,ALIGN=0):
#NOPEN DO HO U0 THETAO SIGMAO CO KD TO SO RHOO LD ALIGN
1 0.5 0. 3.0 45. 45. 100. 0. 30. 0. 0. 0.
#Program control:
#ZMAX ZMIN DISMAX NPRINT
30. 0. 200. 10
The required input data values (all in SI with those for CORMIX (in particular, see Section
units) are discussed in the following. The 4.4 and 4.5 for discharge conditions),
definition of these values is entirely consistent
Block 1: Identifier
LABEL: Any descriptive label/text (should not exceed 50 characters, so that it does not get truncated on
the graphics plots)
Block 2: Fluid and density specification
FLUID: 1 (water) or 2 (air, for atmospheric applications)
IDENOP: 1: in case of water: Density will be calculated from specified temperature and/or salinity
In case of air: Potential density will be calculated from potential temperature assuming
dry adiabatic conditions
2: Density values will be specified directly
LEVAMB: Number of levels for which ambient conditions are given (1 to 10)
Block 3: Ambient Conditions (specify LEVAMB lines)
LEV: Level number (increasing from 1 to LEVAMB)
ZA: Specify vertical level (z-coordinate) (m)
TA : if IFLUID=1 (water): Temperature at ZA (degC) (omit if IDENOP=2)
if IFLUID=2(air): Potential temperature at ZA (degC) (omit if IDENOP=2)
SALA: Salinity at ZA (ppt) (omit ifiDENOP=2 or if IFLUID=2)
RHOA: if IFLUID=1: Density at ZA (kg/m3) (omit ifiDENOP=1)
if IFLUID=2: Potential density at ZA (kg/m3) (omit if IDENOP=1)
UA: Ambient velocity (speed) at ZA (m/s)
TAUA: Angle of ambient velocity vector measured CCW from x-axis (deg) (set = 0. unless velocity
distribution in vertical is skewed, i.e. spiral-type)
Block 4: Discharge Conditions
NOPEN: 1: if SINGLE PORT DISCHARGE (i.e. 1 opening)
>= 3: number of openings (ports) for MULTIPORT DIFFUSER
DO: Port diameter (m) (should include contraction effects if any)
HO: Port center height above x-y plane (m)
U0: Jet exit velocity (m/s)
THETAO: Vertical angle of discharge (deg)
68
-------
CHECKLIST FOR DATA PREPARATION
CORJET -- CORNELL BUOYANT JET INTEGRAL MODEL-- Version 4.10
DOS File Name: Date:
Prepared by:
Label:
Fluid/Density:
Fluid: 1 (water) Density specificaton: 1 (viatemp./sal.) Number of ambient levels:
2 (air) 2 (direct) (1to10)
Ambient Data:
Level No.
Elevation
(m)
Temperature
(°C)
Salinity
(PPt)
Density
(kg/m3)
Velocity
(m/s)
Angle of
velocity (deg)
Discharge Conditions:
Number of openings:
(=1 for single port s.p.)
Port
diameter (m)
Height above
origin (m)
Exit velocity
(m/s)
Vertical
angle (deg)
Horizontal
angle (deg)
Discharge
conc. (any
units)
Coefficient of
decay (/s)
Discharge
temp. (°C)
Discharge
salinity (ppt)
Discharge
density
(kg/m3)
Diffuser
length (m)
(= 0. if s.p.)
Alignment
angle (deg)
(= 0. if s.p.)
Program Control:
Max. vertical Min. vertical Max. distance along Print intervals:
distance (m): distance (m): trajectory (m): (best 5 to 10)
-------
SIGMAO: Horizontal angle of discharge axis measured CCW from x-axis (deg)
Examples: 0. = co-flow, 90. or 270. = cross-flow, 180. = counterflow
CO: Discharge concentration (any units that need not be specified)
KD: Coefficient of substance decay [negative value if growth] (/s)
TO: Discharge temperature (degC) (omit if IDENOP=2)
SO: Discharge salinity (ppt) (omit if IDENOP=2 OR IF IFLUID=2)
RHOO: Discharge density (kg/m3) (omit if IDENOP=1)
LD: Diffuser length (m) (set = 0. [non-blank] if NOPEN=1)
ALIGN: Diffuser alignment angle (deg) measured CCW from x-axis (set = 0. if NOPEN=1)
Examples: 0. = parallel diffuser, 90. = perpendicular diffuser
Block 4: Program Control
ZMAX: Maximum vertical coordinate of interest (m)
ZMIN: Minimum vertical coordinate of interest (m)
ZMAX and ZMIN are cutoffs for + and - buoyancy, respectively!
DISMAX: Maximum distance of interest along trajectory (m)
NPRINT: Print intervals (any positive number less than 100; recommended value 5 to 10; does not affect
accuracy of computation!)
Note on density specification: It is
important to note the mutual exclusivity for the
indirect or direct density specification as listed
above. Omit the values (i.e. leave blank spaces)
depending on the value of the IDENOP
parameter. This can be seen in the preceding
example data file. Up to 10 ambient levels can be
specified for density and velocity distribution. This
is sufficient to replicate complicated observed
ambient profiles. CORJET performs internal
consistency checks to test whether the specified
density distribution is statically stable.
The coordinate system in CORJET can,
in principle be taken as consistent with the
CORMIX1 and 2 conventions (Section 5.2.1), i.e.
the origin at the bottom of the receiving water
body. (In fact, this convention is exercised
whenever CORJET is run from within CORMIX.)
However, since CORJET does not recognize the
dynamic effect of the presence of the actual
bottom boundary it is often convenient to set the
origin at the center of the discharge port. In that
case the port height HO must be entered as 0.0.
x points horizontally in the downstream direction,
y laterally across in the horizontal plane, and z
vertically upward. In the rare case when the
ambient velocity distribution is skewed in the
vertical, the definition of the x direction is best
made by the direction of the ambient velocity at
the level of origin (then TAUA is 0.0 at that level!),
but any other convention is possible, too, and can
be implemented by the choice of the TAUA value
at the level of origin.
The CORMIX system contains upon its
installation several CORJET case studies (see
also Appendix E) that are installed as
CORMIX\POST\CJ\case*.inp. It is recommended
to copy one or more of these files and use the
copy for constructing any future input data file.
6.1.4 CORJET Output Features
Regardless of the access mode (within or
outside of CORMIX) CORJET has two output
mechanisms, a numerical output file and a
graphical display by means of CMXGRAPH.
(a) CORJET Output File:
(a.1) Use within CORMIX:
The output file gets stored as
CORMIX\POST\CJ\/n.CJX where fn is the
CORMIX1 or 2 filename that has been specified
during the data entry. This file can be viewed on-
screen or printed within CORMIX.
A typical CORJET output file generated in
this access mode is shown in Table 6.2 below
corresponding to the input example presented
above. The header information starts with the
banner 'J J J' and then echoes all the pertinent
data that had been supplied to CORMIX and had
been picked up for the CORJET simulation. The
70
-------
underlying C0RMIX1 or 2 flow class is listed. If
one of the unstable or bottom-attaching flow
classes is encountered in this access mode, then
CORJET will not provide any predictions since
a pure jet integral model would not be applicable.
The tabular listing (see Table 6.2 ) gives
the plume values along the trajectory. CORJET
will cut off at a vertical level ZMAX that is equal to
the water depth at discharge or ZMIN = 0.0 (for
negatively buoyant cases) equal to the water body
bottom. In neither case does it compute the
actual boundary approach or impingement
processes (as does the more complete CORMIX
model in which some CORJET elements are, in
fact, integrated, starting with Version 3.0). The
interpretation of data values in this tabular listing
is consistent with that for CORMIX1 or 2 (see
Section 5.2.2).
Table 6.2
Example of CORJET output file when accessed within CORMIX
CORJET PREDICTION FILE:
JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ
Version 4.0, March 1995
CORJET: CORNI
&
UOYANT JET INTEGRAL MODEL
run
. 50
.21
cormix\post\cj\SAMPLE1.CJX
A-PLANT^SUMMER^STRATIFICATION
4/12/96 --18:40:19
for earlier CORMIX1 prediction (metric):
DEEP^RESERVOIR
A-PLANT^SUMMER^STRATIFICATION
cormix\sim\SAMPLEl .CXI
06/2 4/95--22:29:54
.01 CUNITS= PPM
density stratified environment
RHOAB = 999.61 HINT = 15.50 DRHOJ =
UA
FILE NAME:
Label/identifier:
Time of CORJET run:
NEAR-FIELD DATA values
Site name/label:
Design case:
FILE NAME:
Time of CORMIX
HD = 30
STRCND= C
RHOAS = 9 96
FLOCLS= S3
Corresponding CORJET ambient conditions:
LEV ZA RHOA UA TAUA
1 .00 999.61 .01 .00
2 14.75 998.39 .01 .00
3 16.25 996.21 .01 .00
4 30.50 996.21 .01 .00
Pycnocline thickness has been set to 1/10 of upper layer thickness.
Discharge conditions (metric): SINGLE PORT
DO HO
.254 .60
Program control:
ZMAX ZMIN
30.50 .00
U0
3 . 02
THETA0 SIGMA0
10.00 90.00
CO
. 35E+04
KD
. 00E+00
RHOO
998 .21
DISMAX
1525.00
NPRINT
10
Flux variables (based on ambient at discharge level)
Q0 = .153E+00 M0 = .462E+00
Length scales (m) and parameters:
JO
LQ
12.44 Lm
. 2 03E-02 GP0
45.31 Lb
Lmp
FRO
4
52
CD H I
CD O I
Lbp
R
-
3 .
201.
06
31
CORJET
PREDICTION:
Stepsi
ze =
. 2251
Printout
every
10 s
Single
j et/plume:
X
Y
Z
Sc
Cc
B
DIST
Save
Gpc
Flc
. 00
.00
.60
1. 0
. 350E+
04
. 13
.00
1.0
13E-01
52 . 01
. 01
1.23
.82
1. 0
. 350E+
04
. 13
1.25
1.4
16E-01
95 . 03
. 04
3 .45
1
.22
2 . 5
. 142E+
04
.37
3 .50
4.2
50E-02
33 . 42
. 11
5 .65
1
.65
4 . 1
. 852E+
03
.62
5 . 75
7.0
25E-02
21. 98
. 22
7 .85
2
. 13
5 . 8
. 607E+
03
.87
8 .00
9.8
12E-02
19 . 01
. 35
10 . 04
2
.65
7 . 4
. 471E+
03
1 .12
10 .25
12 . 6
32E-03
25 . 46
. 44
11 .13
2
. 92
8 . 3
. 423E+
03
1.25
11 .38
14 . 0
59E-04
50 . 81
Level of buoyancy reversal in stratified ambient.
.53 12.22 3.
.74 14.40 3.
.99 16.61 4.
1.28 18 .83 4 .
1.31 19.05 4.
Maximum jet height
1.62 21.05 4.
1.99 23 .23 3 .
2.19 24.31 3 .
Terminal level in
19
68
06
20
20
1
9
10 . 8
12 . 4
14 .1
14 . 3
. 3 84E+03
. 325E+03
. 2 82E+03
. 248E+03
. 245E+03
has been reached.
05 15.9 .220E+03
63 17.8 .196E+03
37 18.8 .187E+03
stratified ambient
1.37
12 .50
15 .4
. 40E-03
16 . 80
1 .63
14 .76
18 .2
.97E-03
8 . 35
1 .88
17 .01
21 . 0
.13E-02
5 . 70
2 .14
19 .26
23 . 8
.13E-02
4 . 61
2 .17
19 .48
24 .1
.13E-02
4 . 56
2 .40
21.51
26 . 8
.99E-03
4 . 54
2 .66
23 .76
30 . 0
.34E-03
6 . 68
2 .80
24 .89
31 . 6
.2 7E-04
22 . 15
has been reached.
PROGRAM STOPS!
END OF CORJET PREDICTION: Total number of integration steps = 106
JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ
71
-------
The main usefulness of CORJET when
run in this mode lies in the short and separate
display of the near-field buoyant jet only. In some
cases, the pertinent regulatory constraints may be
limited to that region.
(a.2) Use outside of CORMIX:
The output file gets stored as
filename.OUT in the same directory for which the
user had specified the input file (see Section
6.1.2(2)). This file can be viewed on-screen or
printed using any text processor.
The CORJET output file corresponding to
the input data file of Table 6.1 is listed in Table
6.3. The lead-in data provide an echo of the input
data and then lists the calculated length scale and
non-dimensional numbers controlling the mixing
process.
Table 6.3
Example of CORJET output file
CORJET PREDICTION FILE:
JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ
CORJET: CORNELL BUOYANT JET INTEGRAL MODEL Version 4.0, March 1995
FILE NAME:
Label/identifier:
Time of CORJET run:
post\cj\case2.OUT
Case2: SINGLE PORT, STRATIFIED, VARIABLE CURRENT
4/10/96--19:28: 6
Ambient conditions:
LEV ZA TA
1 .00 12 . 00
2 5.00 15 . 00
3 15 . 00 20 .00
No. of levels: 3
SA RHOA
30.00 1022.71
29.50 1021.74
28.00 1019.43
Fluid: Water
UA TAUA
.50 .00
.80 .00
1.20 .00
Density option: 1
Discharge conditions (metric):
DO HO
.500 .00
Program control:
ZMAX ZMIN
30 .00 .00
U0
3 .00
DISMAX
200 .00
THETA0
45 .00
SINGLE
SIGMA0
45 .00
PORT
CO
. 10E+03
KD
. 00E+0
TO
30 . 0
NPRINT
10
. 153E+ 0 0 GP0
Lb
Flux variables (based on ambient at discharge level):
Q0 = .58 9E+ 0 0 M0 = .177E+01 JO
QT0 = .106E+02 QS0 = -.177E+02
Length scales (m) and parameters:
LQ = .44 LM = 3.92 Lm = 2.66
Lmp = 5.61 Lbp = 6.71
FRO = 8.33 R = 6.00
Zone of flow establishment (m):
LE = 1.30 XE = .75 YE = .62
THETAE= 38.34 SIGMAE= 34.00 GAMMAE= 49.43
SO RHOO
.0 995.65
.259E+00
CORJET PREDICTION:
Single jet/plume:
Stepsize =
.2659 Printout every 10 steps
X
Y
Z
Sc
Cc
B |
DIST
Save
Gpc
dTc
dSALc
.00
.00
.00
1 . 0
. 100E+03
.25 |
.00
1. 0
. 2 6E+ 0 0
18 . 0
-30 . 0
. 75
. 62
.86
1 . 0
. 100E+03
.25 |
1 .30
1.4
. 2 7E+ 0 0
20 . 8
-34 . 7
2 .81
1 .50
2 .27
3 . 0
. 334E+02
. 64 |
3 . 96
4 . 6
. 83E-01
5.2
-9.9
5 .22
1 . 96
3 .28
5 . 7
. 176E+02
. 94 |
6 . 62
8 . 3
. 42E-01
2 .1
-5 .1
7 . 74
2 .22
4 . 07
8 .4
. 118E+02
1 .16 |
9.27
12 .1
. 26E-01
. 8
-3 . 3
10 .31
2 .40
4 . 74
11 .2
. 890E+01
1 . 34 |
11 . 93
15 . 8
.18E-01
. 1
-2 .4
12 . 90
2 . 52
5 . 32
14 . 0
. 716E+01
1 .49 |
14 .59
19 . 5
. 13E-01
- . 3
-1 . 9
15 . 51
2 .61
5 . 84
16 . 6
. 601E+01
1 . 62 |
17 .25
23 .2
. 96E-02
- . 6
-1 . 5
18 .12
2 .68
6 .31
19.2
. 520E+01
1 . 74 |
19 . 91
26 . 7
.7 0E-02
- . 8
-1.2
20 . 75
2 . 73
6 . 74
21 . 7
.460E+01
1 . 84 |
22 . 57
30 . 0
. 50E-02
-1 . 0
-1 . 0
23 .38
2 . 78
7 .13
24 .1
.414E+01
1 . 93 |
25.23
33 . 3
. 34E-02
-1 .1
- . 8
26 . 01
2 . 82
7.48
26 .4
. 379E+01
2 . 01 |
27 .89
36 . 3
. 21E-02
-1 . 3
- . 6
28 .65
2 .85
7 .80
28 . 5
. 351E+01
2 . 08 |
30 . 54
39 .1
. 10E-02
-1.4
- . 5
31.29
2 .88
8 .09
30 .4
. 329E+01
2 .14 |
33 .20
41 . 6
. 15E-03
-1 . 5
- .4
31 . 82
2 .89
8 .14
30 . 8
. 325E+01
2 .15
33 . 73
42 .1 -
. 13E-04
-1 . 5
- .4
Terminal level in stratified ambient has been reached.
PROGRAM STOPS 1
END OF CORJET PREDICTION: Total number of integration steps = 123
JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ
72
-------
The actual tabular listing of the numerical
output is divided in two halves by a vertical line.
The left half lists data exactly in the same fashion
as a CORMIX1 or 2 prediction file (see Section
5.2.2). The right half gives additional detailed
information on the following variables:
DIST: distance (m) along the jet
trajectory
Save: average (bulk) dilution, defined on
the basis of total volume flux
within the jet relative to the initial
volume flux (discharge)
Gpc: centerline buoyant acceleration
(m/s2)
dTc: centerline temperature difference
relative to local ambient
temperature (°C) (if IDENOP = 1)
dSALc: centerline salinity difference
relative to local ambient salinity
(ppt) (if IDENOP = 1)
FIc: local densimetric Froude number
(if IDENOP = 2)
In this mode CORJET becomes an
important engineering tool for design sensitivity
analysis -and also for research purposes- to
evaluate the behavior of the near-field processes
to some of the ambient/discharge details, some of
which had to be simplified (schematized) within
the CORMIX approach. The user can learn to
understand through repeated use of CORJET that
plume mixing can indeed often be represented by
simple linear, or even uniform, approximations to
the ambient density structure.
Again, it is emphasized that CORJET
when used alone is not a safe prediction
methodology because of the limiting assumption
of infinite receiving water. For that reason an alert
is printed at the end of each CORJET output file:
Note: CORJET has been used outside the
CORMIX system, assuming unlimited
receiving water.
Carefully examine all results for
possible boundary effects due to
surface, bottom, or lateral
boundaries.
Previous application of CORMIX assures a
careful examination of the interaction of the
discharge with boundaries has been
accomplished.
(b) Graphics display and plotting of CORJET
results:
The graphical display and plotting of the
CORJET prediction results by means of
CMXGRAPH is similar to that of CORMIX results
as described in Section 5.3.
The graphics package can be invoked in
either access mode (within or outside of
CORMIX) immediately after the computation or
independently on any existing CORJET output file
that has been computed earlier. Thus,
CMXGRAPH has been configured to deal with
both CORMIX prediction files and CORJET
output files.
6.2 FFLOCATR: The Far-Field Plume Locator
6.2.1 General Features
Although the main emphasis of CORMIX
is on the near-field mixing behavior of discharges
it can also be used for providing plume
predictions at larger distances in the far-field
provided the flow is not highly irregular with
pronounced recirculating zones and eddies in the
ambient flow.
The CORMIX predicted far-field always
applies to a rectangular schematized cross-
section with a straight uniform channel (see
Sections 4.3.1 and 4.3.2). The FFLOCATR is a
simple method for interpreting the schematized
CORMIX far-field plumes within the actual flow
patterns in natural rivers and estuaries. This
procedure, based on the cumulative discharge
method, is illustrated in Figure 6.2.
The cumulative discharge method, first
proposed by Yotsukura and Sayre (28; see also
19,20), is a convenient approach of dealing with
lateral mixing in natural irregular (but not highly
irregular with recirculating zones!) channels. In
such channel geometry the passive far-field
plume that is vertically mixed, or approaches
vertical mixing, will be positioned around the
"streamline", or more precisely the "cumulative
discharge line", that passes through the plume
73
-------
Figure 6.2: Illustration of the cumulative discharge method for translating the CORMIX predicted far field
plume to the actual flow characteristics in winding irregular rivers or estuaries
74
-------
center when it enters the far-field. Lateral
spreading around this line occurs by lateral
turbulent diffusion and can be enhanced
buoyancy induced processes.
Looking downstream at a particular cross-
section (see Figure 6.2a) the cumulative
discharge q(y) is defined as
y'
q(y"> = /ua(y')H(y')dy'
0
in which y'is the lateral coordinate pointing from
the right bank to the left across the flow (y' differs
from y as defined in CORMIX whose origin is_at
the discharge location), H is the local depth, and ua
is the depth-averaged local velocity. When the
above equation is integrated across the full
channel width Bs then the total discharge will
result Qa = g(BJ. Hence, if the local values q(y')
are divided by Qa the results can be presented in
normalized form as the cumulative discharge lines
ranging from 0% at the right bank to 100% at the
left bank. The full distribution of such cumulative
discharge lines in a river or estuary gives an
appearance of the overall flow pattern that is
important for pollutant transport. Closely spaced
discharge lines are mostly indicative of areas of
large depth and higher velocities as they occur in
the outside portion of river bends or meanders (as
sketched in Figure 6.2a).
In the CORMIX schematization of ambient
flow characteristics and channel cross-section it
is, in fact, useful to keep in mind the cumulative
transport aspects of the ambient flow as remarked
in Section 4.3.1 and 4.3.2. Thus, the uniform
CORMIX flow field with the constant depth
laterally is indeed conforming to a cumulative
discharge distribution with equally spaced
discharge lines, as indicated in Figure 6.2b. It is
then conceptually straightforward to translate the
CORMIX plume prediction back to the actual flow
distribution by calculating and plotting the plume
boundaries within the given cumulative discharge
lines as shown in Figure 6.3c. The actual plume
pattern may then show some surprising features
such as strong "shifting back and forth" between
opposing banks and an apparent "thinning' of the
plume width. These realistic plume features are
simply dictated by the non-uniform flow field.
Further technical details on the
FFLOCATR model can be found in the report on
CORMIX enhancements (8).
6.2.2 Access to FFLOCATR
FFLOCATR can also be accessed in
different ways:
(1) Use within CORMIX:
(1a) It can be accessed at an end of the
prediction after the file has been stored,
by entering the Post-Processor option in
the Iteration Menu.
(1b) It can be accessed on earlier
existing files by directly choosing the Post-
Processor option in the Main Menu.
In either case, once the
FFLOCATR option is chosen the user
must first specify whether a CORMIX1, 2
or 3 simulation should be interpreted for
the far-field with FFLOCATR. Then the
CORMIX filename in the CORMIX\SIM
directory must be specified. Finally, the
user must specify the name of the
cumulative discharge input data file, or if
that does not yet exist, the user can first
create such file by entering data on the
cumulative discharge distribution at
several cross-sections.
(2) Use outside CORMIX:
FFLOCATR can be invoked directly by
typing the command line with three
arguments:
fflocatr CORMIXn fn POSJ\FF\cumdata.FF\
(alternatively, ffl can be typed instead of
fflocatr) where CORMIXn, n = 1, 2 or 3,
specifies which earlier CORMIX
simulation should be analyzed for the far-
field, fn (without path and extension) is
the name of the CORMIX prediction file in
the CORMIX\SIM directory, and cumdata
(with directory designation POST\FF and
fixed extension FFI) is the cumulative
discharge input data file (see following
75
-------
section) existing in directory
CORMIX\POST\FF.
Alternatively if one types:
fflocatr (or simply: ffl)
without the three arguments, the model will
prompt the user for the file information.
6.2.3 FFLOCATR Cumulative Discharge Input
Data File
In general, it is more convenient to
construct the cumdata.FFI file outside of CORMIX
and store it in the CORMIX\POST\FF directory.
This option is described first.
(a) Input Data File Prepared Outside of
CORMIX:
FFLOCATR is a Fortran program and
reads the cumdata. FFI file in open format. An
example is shown in Table 6.4 (corresponding to
the test case discussed in Appendix B).
Table 6.4
Example of a cumulative discharge input data file for FFLOCATR
SHALLOW RIVER CUMULATIVE DISCHARGE (applies to Sample2)
Number of Cross-sections (XS):
3
XS 'Label-' Dist. 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
<> < > < > < > < > < > < > < > < > < > < > < > < >
1 'STA1' 30.5 6.1 12.2 15.9 20.7 27.5 33.6 58.0 76.3 82.4 88.5
2 'STA2' 152.5 9.2 16.8 21.4 24.4 27.5 33.6 36.6 39.7 54.9 79.3
3 'STA3' 305. 18.3 33.6 39.3 45.8 48.8 51.9 54.0 56.4 61.0 67.1
The required input data values (SI units) are:
Line 1: Any descriptive label.
Line 2:
Line 3: NUMXS = Number of cross-sections (1 to 10) for which discharge data values will be
entered
Line 4:
Line 5:
Lines 6ff: NUMXS lines must be entered, each containing the following data:
XS = number of cross-section, numbered sequentially beginning with 1
STALAB = arbitrary label for cross-section, bracketed by apostrophes ' with
maximum total length of 10 characters (e.g. 'RM595' standing for river
mile 595)
YCD = 10 values, representing the position of the cumulative discharge line (m)
measured from the right bank, beginning with the 10% line, incrementing
by 10%, and ending with the 100% line. The 100% line is also equal to
the channel width at that cross-section.
Consistency checks are performed on
each data file to make sure that the entered
values YCD are monotonically increasing.
Essentially two methods can be used for
obtaining the values for the cumulative discharge
positions YCD in specific cases:
1) On the basis of detailed stream-gaging
surveys, for example using the standard methods
employed by the U.S. Geological Survey. This is
the preferable approach for small to medium
streams or rivers.
76
-------
2) Using the results of detailed numerical
models for the flow distribution in open channel
flow. This is preferable for larger rivers or
estuaries.
The primary application for FFLOCATR is
for bounded channels such as streams, rivers or
estuaries. The model will not execute when it
encounters a CORMIX file for a design case
involving an unbounded ambient flow.
Nevertheless, it may sometimes be useful
to provide a detailed far-field plume delineation
also for unbounded flow situations, such as
coastal areas or lakes. This can be done when
detailed hydrographic data or numerical model
predictions describing the flow distribution in the
near-shore where the plume may be located are
available. A CORMIX simulation can then be re-
run specifying a "bounded channel" with a width
equal to some arbitrary bounding offshore
streamline. The YCD data can then be specified
relative to the value of that chosen streamline.
FFLOCATR will thus predict the far-field plume
location in the irregular coastal zone (assuming
recirculating eddies do not exist in the flow).
(b) Input Data File Prepared Within CORMIX:
The user can generate the data file with
exactly the same data structure as discussed
above also within CORMIX. The system will
prompt the user for the individual data items (up
to 10 cross-sections can be entered) and then for
a cumdata filename. The file will then be stored
automatically in directory CORMIX\POST\FF with
extension FFI.
6.2.4 FFLOCATR Output Features
FFLOCATR generates an output file
CORMIX\POST\FF\/h.FFX indicating that the far-
field plume prediction for the CORMIX design
case fn has been interpreted under the actual far-
field flow distribution. This file can be inspected
on-screen when in CORMIX or externally with any
text processor, and can be printed out. No
graphics plotting option exists for this file.
As an example, Table 6.5 on the next
page shows the output file that combines the
cumulative discharge input data of Table 6.4 with
the CORMIX2 plume predictions that are part of
Appendix B. The output file preceded by the
banner 'FFF' consists of three parts. The first part
lists some of the underlying CORMIX data
including file information. The second part
echoes the complete cumulative discharge input
data file.
The actual results of the FFLOCATR
translation routine are given in the third part. For
each of the specified cross-sections (stations) the
output file lists the station label, the downstream
distance, and the position of plume center, left
edge and right edge, respectively, each measured
from the right bank, and the local centerline
dilution and concentration. Data of this kind can
then readily be used to prepare plots of far-field
plumes superimposed on maps of the actual flow
field. This last step has been illustrated in Figure
6.2c.
It should be understood that the plume
centerline in the far-field does not necessarily
coincide with the cumulative discharge line that
passes through the offshore discharge location
(as has been illustrated in Figure 6.2 where a co-
flowing discharge had been assumed). The
plume centerline can shift because of near-field
processes, as in case of a cross-flowing
discharge, or if bank interaction occurs in the far-
field, causing the centerline to shift to one
bank/shore.
77
-------
Table 6.5
Example of FFLOCATR output file
FFLOCATR RESULTS FILE:
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
FFLOCATR: FAR-FIELD PLUME LOCATOR Version 1.0, March 1994
Output FILE NAME:
Time of FFLOCATR run:
POST\FF\SAMPLE2.FFX
1995/ 6/ 2-- 8 : 54 : 3 £
FAR-FIELD DATA values from earlier CORMIX2 prediction:
FILE NAME: SIM\SAMPLE2.cx2
Site name/label: B-PLANT^SHALLOW-RIVER
Design case: LOW-FLOW^7Q10
Time of CORMIX2 run: 09/20/94 --15 : 24 :11
Channel characteristics (metric):
BS = 50.00 HA = .30 UA
BANK = right DISTB = 20.00
STRCND= U uniform density environment
. 54
Pollutant data:
CO = 100.00
CUNITS=
PERCENT
CUMULATIVE DISCHARGE DATA (m):
FILE NAME:
Data label:
Number of XS:
XS'Label-' Dist.
1 'STA1 ' 3 0.5
2 'STA2 ' 152.5
POST\FF\SH-RIVER.ffi
SHALLOW RIVER CUMULATIVE DISCHARGE
3
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
6.10 12.20 15.90 20.70 27.50 33.60 58.00 76.30 82.40 88.00
9.20 16.80 21.40 24.40 27.50 33.60 36.60 39.70 54.90 79.00
3 'STA3 ' 305.0 18.30 33.60 39.30 45.80 4f
JO 51.90 54.00 56.40 61.00 67.00
FAR-FIELD PLUME PROPERTIES (m):
XS
#
1
2
3
Label-
STA1
STA2
STA3
Distance
downstream
30 .50
152.50
305.00
Left
edge
27 .50
27 .50
48 .80
Plume Right
centerline edge
20.70 13.28
24.40 17.80
45.80 34.32
Dilution
30.1
31.4
33 . 0
Cone .
. 332E+01
. 318E+01
. 3 03E+01
END OF FFLOCATR: FAR-FIELD PLUME LOCATOR
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
78
-------
VII Closure
7.1 Synopsis
The Cornell Mixing Zone Expert System
(CORMIX) is a series of software subsystems for
the analysis, prediction, and design of aqueous
toxic or conventional pollutant discharges into
diverse water bodies. The major emphasis is on
the geometry and dilution characteristics of the
initial mixing zone including compliance with
regulatory constraints. The system also predicts
the behavior of the discharge plume at larger
distances in the far-field.
The highly user-interactive CORMIX
system is implemented on IBM-PC compatible
microcomputers and consists of three
subsystems. These are: CORMIX1 for
submerged single port discharges, CORMIX2 for
submerged multiport diffuser discharges and
CORMIX3 for buoyant surface discharges. The
basic CORMIX methodology relies on the
assumption of steady ambient conditions.
However, recent versions also contain special
routines for the application to highly unsteady
environments, such as tidal reversal conditions, in
which transient recirculation and pollutant build-up
effects can occur.
In addition, two post-processing models
are linked to the CORMIX system, but can also be
used independently. These are CORJET (the
Cornell Buoyant Jet Integral Model) for the
detailed analysis of the near-field behavior of
buoyant jets, and FFLOCATR (the Far-Field
Plume Locator) for the far-field delineation of
discharge plumes in non-uniform river or estuary
environments.
This user's manual gives a comprehensive
and uniform description of all three CORMIX
subsystems; it provides advice for assembly and
preparation of required input data; it delineates
ranges of applicability of the three subsystems; it
provides instruction for the interpretation and
graphical display of system output; and it
illustrates practical system application through
several case studies.
7.2 System and Documentation Availability
The CORMIX system programs can be
obtained from:
U.S. EPA - Center for Environmental
Assessment Modeling (CEAM)
Environmental Research Laboratory
960 College Station Road
Athens, GA 30605-2700 USA
Tel. 706-546-3549 (or FTS 250-3590)
Fax:706-546-3402
E-mail: ceam@athens.ath.epa.gov
As of the release of this manual (late 1996) the
following versions of CORMIX are available:
CORMIX Version2.1 (1993, without graphics and
post-processor features) and Version3.1 (August
1996, as described in this report). The models
can be obtained by mail or over the electronic
bulletin board operated by CEAM. Information on
program installation and computer configuration
are also provided by CEAM. The ftp address is:
ftp://ftp.epa.gov/epa_ceam/wwwhtml/ceamhome.htm
The distribution versions of CORMIX
contain only the executable code of the
FORTRAN programs HYDROn; they do not
include the source code. The source code can be
requested separately by writing to CEAM at U.S.
EPA-ERL and giving the reason for code
inspection and possible manipulation. The full
code, while made up of simple individual
modules, is complex with multiple
interdependencies; only experienced research
personnel should attempt this work when
engaged in comparison of model predictions to
new field or laboratory data.
The technical documentation
reports(5,6,7,8) are available as U.S. EPA and
NITS publications, and have also been issued as
technical reports of the DeFrees Hydraulics
Laboratory.
79
-------
7.3 User Support
Technical and scientific support for
CORMIX under contract from the USEPA is
provided by:
Dr. Robert L. Doneker
Department of Environmental Science and
Engineering
Oregon Graduate Institute
PO Box 91000
Portland, OR 97291-1000
Tel. 503-690-4053, Fax. 503-690-1273
email: doneker@ese.ogi.edu
This includes assistance on problems of system
installation and execution, and advice on the
specification of input data as well as interpretation
of CORMIX output.
Any high-quality field or laboratory data on
effluent mixing processes is a valuable asset for
any future development or updates on CORMIX.
Transmittal of such data to the following address
will be greatly appreciated:
Prof. Gerhard H. Jirka
Institute for Hydromechanics
University of Karlsruhe
PO Box 6380
D-76128 Karlsruhe, GERMANY
Tel. (49) 721/608-2200, Fax. (49) 721/66-16-86
80
-------
Literature References
(1) "Technical Support Document for Water (8)
Quality-based Toxics Control," U.S. EPA,
Office of Water, Washington, DC,
September, 1991.
(2) "Assessment and Control of
Bioconcentratable Contaminants in
Surface Waters," U.S. EPA, Office of
Water, Washington, DC, March, 1991.
(3) Jirka, G. H., "Use of Mixing Zone Models
in Estuarine Waste Load Allocation," Part (9)
III of Technical Guidance Manual for
Performing Waste Load Allocations. Book
III: Estuaries, Ed. by R. A. Ambrose and J.
L. Martin, U.S. EPA, Washington, D.C.,
EPA-823-R-92-004, 1992.
(4) Muellenhoff, W. P., et al.."Initial Mixing (10)
Characteristics of Municipal Ocean
Discharges (Vol I & II)," USEPA,
Environmental Research Laboratory,
Narragansett, Rl, 1985.
(5) Doneker, R. L., and G. H. Jirka, (11)
"CORMIX1: An Expert System for Mixing
Zone Analysis of Conventional and Toxic
Single Port Aquatic Discharges", U.S.
EPA, Environmental Research
Laboratory, Athens, GA, EPA-600/600/3-
90/012, 1990. (12)
(6) Akar, P. J. and G. H. Jirka, "CORMIX2: An
Expert System for Hydrodynamic Mixing
Zone Analysis of Conventional and Toxic
Submerged Multiport Discharges," U.S.
EPA, Environmental Research Laboratory
Athens, GA, EPA/600/3-91/073,1991. (13)
(7) Jones, G.R., J.D. Nash and G.H. Jirka,
"CORMIX3: An Expert System for Mixing
Zone Analysis and Prediction of Buoyant
Surface Discharges", Tech. Rep.,
DeFrees Hydraulics Laboratory, School of
Civil and Environmental Engineering, (14)
Cornell University, 1996, (also to be
published by U.S. Environmental
Protection Agency, Environmental
Research Lab, Athens, GA).
Jirka, G.H., P.J. Akar and J.D. Nash,
"Enhancements to the CORMIX Mixing
Zone Expert System: Technical
Background", Tech. Rep., DeFrees
Hydraulics Laboratory, School of Civil and
Environmental Engineering, Cornell
University, 1996, (also to be published by
U.S. Environmental Protection Agency,
Tech. Rep., Environmental Research Lab,
Athens, GA).
Doneker, R.L. and G.H. Jirka, "Expert
Systems for Design and Mixing Zone
Analysis of Aqueous Pollutant
Discharges", J. Water Resources
Planning and Management. ASCE, Vol.
117, No.6, 679-697, 1991.
Jirka G. H. and R. L. Doneker,
"Hydrodynamic Classification of
Submerged Single Port Discharges", J,
Hydraulic Engineering. ASCE, Vol.117,
1095-1112, 1991.
Jirka G. H. and P. J. Akar, "Hydrodynamic
Classification of Submerged Multiport
Diffuser Discharges," J. Hydraulic
Engineering. ASCE, (117), 1113-1128,
HY9, 1991.
Akar, P.J. and G.H. Jirka, "Buoyant
Spreading Processes in Pollutant
Transport and Mixing. Part I: Lateral
Spreading in Strong Ambient Current", J,
Hydraulic Research. Vol. 32, 815-831,
1994.
Akar, P.J.and G.H. Jirka, "Buoyant
Spreading Processes in Pollutant
Transport and Mixing. Part II: Upstream
Spreading in Weak Ambient Current", J,
Hydraulic Research. Vol. 33, 87-100,
1995.
Mendez Diaz, M.M. and G.H. Jirka,
"Trajectory of Multiport Diffuser
Discharges in Deep Co-Flow", 1
Hydraulic Engineering. ASCE, Vol.122,
HY6, 1996 (in press).
81
-------
(15) Jones, G.R., J.D. Nash and G.H. Jirka,
"Buoyant Surface Discharges into Water
Bodies, Part 1: Classification," J,
Hydraulic Engineering. ASCE, (submitted
1996).
(16) Jones, G.R. and G.H. Jirka, "Buoyant
Surface Discharges into Water Bodies,
Part 2: Prediction," J. Hydraulic
Engineering. ASCE, (submitted 1996).
(17) J.D. Nash and G.H. Jirka, "Buoyant
Surface Discharges into Unsteady
Ambient Flows", Dynamics of
Atmospheres and Oceans. 24, 75-84,
1996.
(18) Jirka G. H., "Multiport Diffusers for Heat
Disposal: A Summary," J. Hydraulics
Division. ASCE, (108), HY12, pp. 1423-
68, 1982.
(19) Holley, E. R. and G. H. Jirka, "Mixing in
Rivers," Technical Report E-86-11, U.S.
Army Corps of Engineers, Washington,
DC, 1986.
(20) Fischer, H. B. et al.. Mixing in Inland and
Coastal Waters. Academic Press, New
York, 1979.
(21) "Water Quality Standards Handbook,"
U.S. EPA, Office of Water Regulations
and Standards, Washington, DC, 1984.
(22) "Technical Guidance Manual for the
Regulations Promulgated Pursuant to
Section 301 (g) of the Clean Water Act of
1977 (Draft)," U.S. EPA, Washington, DC,
August, 1984.
(23) "Revised Section 301 (h) Technical
Support Document," EPA 430/9-82-011,
U.S. EPA, Washington, DC, 1982.
(24) Chow, V. T., Open Channel Hydraulics.
McGraw-Hill, New York, 1959.
(25) Jirka, G.H. and Fong, H.L.M., "Vortex
Dynamics and Bifurcation of Buoyant Jets
in Crossflow", J. Engineering Mechanics
Division. ASCE, Vol.107, pp. 479-499,
1981.
(26) Jirka, G.H., "Single and Multiple Buoyant
Jets in Crossflow", J. Hydraulic Research.
(submitted 1996).
(27) Baumgartner, D.J., W.E. Frickand P.J.W.
Robert, "Dilution Models for Effluent
Discharges (Third Edition)", U.S. EPA,
Pacific Ocean Systems Branch, Newport,
OR, EPA/600/R-94/086, 1994.
(28) Yotsukura, N. and W.W. Sayre,
"Transverse mixing in natural channels",
Water Resources Research. Vol.12. 695-
704, 1976.
82
-------
Appendix A
Flow Classification Diagrams for the Three CORMIX Subsystems
CORMIX1: Submerged Single Port Discharges 84
CORMIX2: Submerged Multiport Diffuser Discharges 88
CORMIX3: Buoyant Surface Discharges 91
83
-------
TEST FOR PLUME TRAPPING
IN A LINEARLY STRATIFIED
LAYER (HEIGHT H#)
Cross-flow
Dominated
Stratification
Dominated
Z.~
.1/3 ,
.?/s
Lm »
-m
CTI
Vh0
H.
<1
Z, + h0
>0
SI
H
z
~
L'm
CT2
>1
<0
z
1 ~
Lb Lk
CT4
z
l ~
L'b
CTS
Terminal height
Z.
AMBIENT STRATIFICATION
UNIMPORTANT
Approximate Ambient Density
with Vertical Mean Value
NEGATIVELY BUOYANT JET
(or Downward Oriented Jet)
BEHAVIOR DOMINATES
FLOW CLASSES
FOR
AMBIENT STRATIFICATION
Figure A.1: CORMIX1 Classification: Assessment of ambient density stratification and different flow classes for internally trapped
-------
90* < Qa <45*
0^4 5*
FLOW CLASSIFICATION
BUOYANT SUBMERGED
DISCHARGES IN
UNIFORM DENSITY LAYER
Deep
Layer
with
Weak
Momentum
Weakly
Buoyant
Figure A.2: CORMIX1 Classification: Behavior of positively buoyant discharges in uniform ambient layer flow
-------
NEGATIVELY BUOYANT JET
(OR DOWNWARD ORIENTED JET)
IN UNIFORM DENSITY LAYER (HEIGHT Hs)
Buoyancy/
Dominate*
Figure A.3: CORMIX1 Classification: Behavior of negatively buoyant discharges in uniform layer flow (Flow Classes NV and NH)
-------
CLASSIFICATION BOTTOM ATTACHMENT
SI, S4, VI, V2
HI, H2, NVI
I NHI, NH3, NH4
Q Q /c2S
Yes
Lill-Ofl
C2C
(..) Al
No
No Lill - Off
Recirculation
Recirculation
|S3, HI, H3.H4
H2, NHI, NH2
|NH3, NH4
tan fl„ < 0.2 -
•an 8. < 0.2-:
CI?
/C2t
-------
Figure A.5: CORMIX2 Classification: Assessment of ambient density stratification and different flow classes for internally trapped
-------
I
POSITIVELY BUOYANT
MULTIPORT OIFFUSER DISCHARGE
IN UNIFORM LAYER (HEIGHT Hs)
00
to
tMU*COS20)Z fM-£4oh«
Shallow Layer
Unstable Discharge
S' Side View
P = Plon View
Figure A.6: C0RMIX2 Classification: Behavior of positively buoyant multiport diffuser discharges in uniform ambient layer flow
!
-------
NEGATIVELY BUOYANT
MULTIPORT DIFFUSER OISCHARGE
IN UNIFORM LAYER (HEIGHT H$)
Strong^
Buoyoncv/ •
Weak
Cross-llow
MNUI
MNU2
MNU3
MNU4
MNUS
MNU6
_^S2S
P
P
-r.
I}^p
Shallow Layer
Unstable
Flow Classes MNU7 - MNUI4
(Vertically Fully Mixed)
(Correspond to Flow Classes
MU2-MU9, Respectively,
with the Exception of
Bottom Reslralilicolion
in the For Field)
S'Slde View
P*Plon View
*
OK (user-Induced Flows Near Bottom (nol fully mined)
Figure A.7: CORMIX2 Classification: Behavior of negatively buoyant multiport diffuser discharges in uniform ambient layer flow
-------
FLOW CLASSIFICATION FOR BUOYANT SURFACE DISCHARGES
Figure A.8: CORMIX3 Classification: Assessment of buoyant surface discharges as free jets, shoreline-attached jets, wall jets, or
-------
&
92
-------
Appendix B
C0RMIX1: Submerged Single Port Discharge in a Deep Reservoir
This case study illustrates the application
of CORMIX1 to the prediction of the effluent from
a small manufacturing plant into a large and deep
stratified reservoir.
B.1 Problem Statement
A manufacturing plant (A-Plant) is
discharging its effluent into an adjacent deep
reservoir. The plant design flowrate is 3.5 mgd (~
0.15 m3/s). The effluent contains heavy metal at
a concentration of 3500 ppb, and is released at a
temperature of 68 °F (= 20 °C). The density of the
effluent at this low concentration can be
considered equivalent to freshwater.
The existing reservoir has been formed by
flooding a river valley. The reservoir length is
about 60 miles. The water level in the reservoir is
fluctuating depending on the release operation at
the downstream dam with its hydropower
installation. During summer conditions, the
reservoir level is typically at an elevation of 710 ft
above sea level. This results in a reservoir width
of about 4000 ft (~ 1200 m) and a maximum
depth of 310 ft (~ 95 m) at the discharge location.
The mean river flow into the reservoir during the
summer low-flow conditions is about 18,540 cfs (~
525 m3/s). The typical temperature of the
inflowing river water is 55 °F (~ 13 °C).
Figure B.1 shows the local bathymetry (as
obtained from a USGS map) in the vicinity of the
proposed discharge. Since the discharge is very
small relative to the reservoir size and the
ambient flowrate, it is expected that mostly local
conditions will be important, and not overall
reservoir dimensions. (Note: Any such
conjecture has to be verified against the final
simulation results, and adjustments have to be
made if needed.)
Temperature data as a function of depth
obtained from field measurements in the center of
the reservoir show a significant temperature
stratification (see Figure B.2), as is typical for
such deep reservoirs during summer conditions.
The stratification can be expected to be
horizontally uniform and therefore similar
conditions will hold at the discharge site. Also,
the river inflow is colder than the surface layer of
the stratified reservoir. The reservoir has a
selective withdrawal structure at the dam,
therefore it can be expected that the river water
will flow predominantly in a vertically limited layer,
that may extend from a depth of about 35 m to the
surface. The velocity of that flow is estimated at
about 1.5 cm/s (~ 0.015 m/s), given the 35 m thick
layer and an about 1000 m width at that elevation.
(Note: More detailed hydrodynamic
investigations, using available models for
stratified reservoir dynamics, can be used to
obtain more precise estimates of the velocity field.
Generally, however, it cannot be assumed that
the velocity in stratified reservoirs is given by the
simple average of the flowrate divided by the
cross-sectional area.)
The proposed discharge location on the
side slope of the cross-section is also shown in
Figure B.1: a submerged single port discharge at
an elevation of 610 ft above sea level, i.e. at a
local depth of 100 ft (~ 30.5 m) below the surface,
is proposed in the initial design phase. The port
diameter is 10 in (~ 0.254 m) and is located 2 ft (~
0.6 m) above the local bottom. The discharge is
pointing offshore and is angled upward at 10 °.
The discharge is subject to State mixing
zone regulations whereby the mixing zone width
is less than 10% of the width of the water body.
Furthermore, the heavy metal in the effluent is
considered toxic with CMC and CCC limits of
1200 and 600 ppb, respectively.
B.2 Problem Schematization and Data
Preparation
Figure B.3 is the data checklist that
summarizes the CORMIX1 input for the present
problem. The ambient water body has been
characterized as unbounded in line with the
expectation that the discharge plume will be small
93
-------
Design Elevation
710 ft I
ELEVATION (ft)
HD- 100 ft'
HA - 115 ft 3q g m
- 35.0 m
Oi«cfcM?« Pip* w
\—5
Schematic
- -600
Rectangular - -
Actual Hectang
Cross-Section Cross-Section
View Looking Downstream
( 1 i 1 1 1 1 1—
700 600 500 400 300 200 100
Distance From Shore (ft)
500
Figure B.1: Local details of Deep Reservoir cross-section and C0RMIX1 schematization
TEMPERATURE (8C)
Figure B.2: Temperature field data as a function of depth and CORMIX1 representation of
Type C temperature profile
94
-------
CHECKLIST FOR DATA PREPARATION
CORMIX - CORNELL MIXING ZONE EXPERT SYSTEM - Version 3.1,3.2
SITE Name A-Plant Deep Reservoir Date:
Design CASE bummer stratification ~ prepared by:
DOS FILE NAME
GHJ
Sample 1
(w/o extension)
AMBIENT DATA:
Water body depth 35.0
Depth at discharge 30.5
If steady: Ambient flowrate -
.m
.m
_m3/s or:
hr
Water body is SSiMteiti/unbounded
If bounded: Width - m
Appearance VSM
Ambient velocity 0.015 m/s
If tidal: Tidal period
At time hr before/at/after slack:
Manning's n
Wind speed
Density data:
Water body is
If uniform:
If stratified:
Stratification type
If B/C: Pycnocline height
Q.Q2 or
_2 m/s
Max. tidal velocity
Tidal velocity at this time
Darcy-Weisbach f
. m/s
m/s
fresh/salt water
-A/B/C
15.5
UNITS: Density...kg/m3 / Temperature..,°C
If fresh: Specify as ctaoaitv/temD. values
Average density/temp.
BSttSit^temp. at surface
B«W8Wy/temp. at bottom
If C: B»hSj*fftemp. jump
28.1
ITT
-gnr
DISCHARGE DATA:
Specify geometry for CORMIX1 or 2 or 3
SUBMERGED SINGLE PORT DISCHARGE - CORMIX1
Nearest bank is on teft/riaht Distance to nearest bank
Vertical angle THETA 10 0 Horizontal angle SIGMA
Port diameter 0.254 m or: Port area
Port height
46.0
~5C—
0.6
SUBMERGED MULTIPORT DIFFUSER DISCHARGE - CORMIX2
Nearest bank is on left/riaht Distance to onej
Diffuser length m ^lo-ottl€rendpoint
Total number of openings m
Port diameter rrfwith contraction ratio
Diffuser arranqement/tyoe--:::^~'unidirectional / staged / alternating or vertical
Alignment_3Dgte"GXMMA 0 Horizontal angle SIGMA
"angle THETA ° Relative orientation BETA
BUOYANT SURFACE DISCHARGE - CORMIX3
Discharge located on
Horizontal angle SIGMA
Depth at discharge
If rectangular
discbafagcHannel: Depth
left/right bank Configurali
rudino: Dist. from bank_
Bottom slope
If circular Diameter^
Bottom invert depth,
i7Drotrudina/co-flowino
Effluent: Flow rate
Effluent density
Heated discharge?
Concentration units
Conservative substance?
0.153 m3/s or; Affluent velocity
kg/m3 or: Effluent temperature
vss/no If yes: Heat loss coefficient ~
ppb Effluent concentration 3bUU
ves/fiO If no: Decay coefficient
" m/s
7070 oq
~ W/m2,°C
/ day
MIXING ZONE DATA:
Is effluent toxic? ves/rtox
WQ stand./conventional poll ? y«s/no
Any mixing zone specified? ves/rax
If yes: CMC 1200 CCC 600
If yes: value of standard -
If yes: distance m or width 120 % or m
or area - % or m2
Region of interest
3500
m
Grid intervals for display
20
Figure B.3: Data preparation checklist for A-Plant Deep Reservoir design case study using
CORMIX1
95
-------
in size relative to the reservoir width.
Furthermore, since (1) the discharge elevation is
well above the lowest point of the reservoir and
(2) the plume is expected to rise toward the
surface, the ambient water depth is taken as 150
ft (-35.0 m) only.
The depth at the discharge corresponds to
the local depth at the discharge location.
Because of the sloping bank from the discharge
to the near shoreline, the distance to bank (46 m)
corresponds to one-half of the actual distance
from the outlet to the shoreline at the water
surface. The ambient velocity corresponds to the
estimate made above for the stratified water body.
A Manning's n of 0.02 describes the smooth
bottom.
Density data is simply entered via the
temperature values of the fresh water body. A
Stratification Type C is chosen to describe the
actual temperature profile.
The discharge data values summarize the
discharge situation as described above. Finally,
the mixing zone specifications include a width
value of 120 m, corresponding to 10 % of the
actual width of 1200 m. Information is desired
over about one mile (~ 1600 m) which represents
the region of interest (ROI) limitation.
B.3 CORMIX1 Session and Results
If desired by the user, CORMIX1 provides
a summary of the data as they are entered, and
then a full record of the simulation sequence and
final results. This session summary report is
shown in Table B.1. Of particular interest to the
user are the evaluations in program element
PARAM and CI_ASS. Note, that the computed
length scales Lm' andbL' are quite small,
indicating that the jet or plume will be trapped
quickly by the ambient stratification; thus, this is
the first numerical indication that the near-field
jet/plume will indeed be small relative to the
reservoir. The ambient flow related scales Lm and
Lb are quite large, indicating that the ambient
velocity is very weak. The resulting flow class S3
is dominated by the ambient stratification; the
plume will be limited to the lower layer of the
stratification. The user should also consult the
description of flow class S3 that is available
during the CORMIX1 session (not reproduced
here). The detailed plume properties are
computed in program element HYDRO, and are
displayed in the Fortran CORMIX1 prediction file
(see Table B.2, discussed in more detail further
below).
Many important features of the plume
prediction are summarized in program element
SUM of the session record (see Table B.1).
Notably, all aspects pertaining to mixing zone
regulations are contained in that summary. For
example, it can be seen quickly from that
summary that the present discharge configuration
meets all three toxic dilution zone (TDZ) criteria
and also the regulatory mixing zone (RMZ)
limitation. Obviously, other ambient conditions
and discharge variations should be considered in
additional simulations before a design such as
this should be deemed fully satisfactory.
B.4 Graphical Displays of Detailed Plume
Predictions
As for most engineering studies it is
desirable to produce graphical displays for
visualization of the predicted results. The data
contained in the CORMIX1 prediction file (Table
B.2) form the basis for such plots. Unfortunately,
it is often difficult to display all plume features in
one single plot because the plume may contain a
lot of near-field details while extending over large
distances into the far-field. A short examination of
Table B.2 proves that point: The plume gets
quickly trapped within a very limited near-field but
with considerable mixing (see MOD110 =
CORJET oftheCORMIXI prediction). Yet after
that the plume extends over large distances into
the far-field forming a wide thin layer within the
stratified reservoir (see MOD142).
Using the graphics package CMXGRAPH,
two plots have been prepared to display the
jet/plume side view in the near-field, using
distorted and undistorted 1:1 scales, respectively,
(Figure B.4) and the plan view in the near-field
and larger scale far-field (Figure B.5) of the
effluent plume. Figure B.4 shows the initial
trajectory of the slightly upward curved jet that
rises to maximum level of 4.29 m and then gets
trapped at an elevation of 3.44 m above the local
bottom. In the trapping stage the jet undergoes a
complicated transition (MOD137) to the
horizontally spreading layer. CORMIX1 predicts
96
-------
Table B.1
CORMIX Session Report for A-Plant discharge into Deep Reservoir with summer stratification
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
CORMIX: CORNELL MIXING ZONE EXPERT SYSTEM
CORMIX v.3.10 June 1995
SITE NAME/LABEL: Sample 1
DESIGN CASE: Sunnier stratification
FILE NAME: SAMPLE1 #
Using subsystem CORMIXl: Submerged Single Port Discharges
c«-arf of sessions 08/25/96——16: 37? 01
*****************************************************************************
SUMMARY OF INPUT DATA:
AMBIENT PARAMETERS:
Cross-section
Average depth
Depth at discharge
Ambient velocity
Darcy-Weisbach friction factor
Calculated from Manning's n
Wind velocity
Stratification Type
Surface temperature
Bottom temperature
Temperature below thermocline
Calculated FRESH-WATER DENSITY values
Surface density RHOAS
Bottom density RHOAB
Stratification height HINT
Density below pycnocline RHOAP
HA
HD
UA
F
UW
STRCND
unbounded
35
30.5
m
.015 ra/s
0.0096
.02
2 m/s
28.1 degC
11.0 degC
19.10 degC
996.2053 kg/mA3
999.6071 kg/mA3
15.5 m (pycnocline level)
998.3866 kg/nT3
DISCHARGE PARAMETERS:
Nearest bank
Distance to bank
Port diameter
Port cross-sectional area
Discharge velocity
Discharge flowrate
Discharge port height
Vertical discharge angle
Horizontal discharge angle
Discharge temperature (freshwater)
Corresponding density
Density difference
Buoyant acceleration
Discharge concentration
Surface heat exchange coeff.
Coefficient of decay
DISCHARGE/ENVIRONMENT LENGTH SCALES:
LQ =» 0.22 m Lm =
LM » 12.42 m Lm' *
Submerged Single
= right
Port Discharge
DISTB
=.
46. m
DO
.254 m
AO
s
0.0506 mA2
U0
=
3.01 m/s
Q0
=
.153 mA3/s
H0
=t
. 6 m
THETA
3S
10 deg
SIGMA
a
90. deg
ir)
=
20.0 degC
RHOO
s
998.2051 kg/mA3
DRHO
=
1.3548 kg/mA3
GP0
s
.0133 m/sA2
CO
=
3500 PPB
KS
=
0 m/s
KD
=
0 / s
45.31
4.94
Lb
Lb'
602.57 m
3.11 m
51.96
201.30
NON-DIMENSIONAL PARAMETERS:
Port densimetric Froude number FRO
Velocity ratio R a
MIXING ZONE / TOXIC DILUTION ZONE / AREA OF INTEREST PARAMETERS:
Toxic discharge = Yes
CMC concentration CMC ¦ 1200 PPB
CCC concentration CCC =» PpB
Water quality standard ¦ given by CCC value
Regulatory mixing zone ™
Regulatory mixing zone specification « width
Regulatory mixing zone value a 120 m (m 2 if area)
****?i*^***i****************************************************************
HYDRODYNAMIC CLASSIFICATION:
J FLOW CLASS « S3 |
The specified ambient density stratification is important, the discharge
near field flow is confined to the lower layer by the ambient density
stratification.
MIXING ZONE EVALUATION (hydrodynamic and regulatory summary):
X-Y-Z Coordinate system:
Origin is located at the bottom below the port center:
46. m from the right bank/shore.
Number of display steps NSTEP * 20 per module.
97
-------
NEAR-FIELD REGION (NFR) CONDITIONS :
Note: The NFR is the zone of strong initial nixing. It has no regulatory
implication. However, this information may be useful for the discharge
designer because the nixing in the NFR is usually sensitive to the
discharge design conditions.
Pollutant concentration at edge of NFR - 98.2267 PPB
Dilution at edge of NFR « 35.6
NFR Location: x » 98.19 m
(centerline coordinates) y » 24.63 m
2 « 3.43 n
NFR plume dimensions: half-width 9 191.86 m
thickness » .94 m
Buoyancy assessment:
The effluent density is less than the surrounding ambient water
density at the discharge level.
Therefore, the effluent is POSITIVELY BUOYANT and will tend to rise towards
the surface.
Stratification assessment:
The specified ambient density stratification is dynamically important.
The discharge near field flow is trapped within the linearly stratified
ambient density layer.
UPSTREAM INTRUSION SUMMARY:
Plume exhibits upstream intrusion due to low ambient velocity or strong
discharge buoyancy.
Intrusion length » 90.24 m
Intrusion stagnation point » -87.98 m
Intrusion thickness = 1.29 m
Intrusion half width at impingement = 191.86 m
Intrusion half thickness at impingement = .94 m
************************ TOXIC DILUTION ZONE SUMMARY ************************
Recall: The TDZ corresponds to the three (3) criteria issued in the USEPA
Technical Support Document (TSD) for Water Quality-based Toxics Control,
1991 (EPA/505/2-90-001).
Criterion maximum concentration (CMC) » 1200 PPB
Corresponding dilution - 2.9
The CMC was encountered at the following plume position:
Plume location: x » .05 m
(centerline coordinates) y « 3.93 m
z ® 1.31 m
Plume dimensions: half-width = .10 m
thickness « .10 n
CRITERION 1: This location is within 50 times the discharge length scale of
Lq = 0.22 m.
+++++ The discharge length scale TEST for the TDZ has been SATISFIED. ++++++
CRITERION 2: This location is within 5 times the ambient water depth of
HD = 30.5 m.
++++++++++ The ambient depth TEST for the TDZ has been SATISFIED. +++++++++++
CRITERION 3: This location is within one tenth the distance of the extent
of the Regulatory Mixing Zone of 98.19 m downstream.
+++++ The Regulatory Mixing Zone TEST for the TDZ has been SATISFIED. ++++++
The diffuser discharge velocity is equal to 3.01 m/s.
This exceeds the value of 3.0 m/s recommended in the TSD.
*** All three CMC criteria for the TDZ are SATISFIED for this discharge. ***
********************** REGULATORY MIXING ZONE SUMMARY ***********************
The plume conditions at the boundary of the specified RMZ are as follows:
Pollutant concentration = 98.226660 PPB
Corresponding dilution = 35.6
Plume location: x » 98.19 m
(centerline coordinates) y =» 24.63 m
z - 3.43 n
Plume dimensions: half-width » 191.86 m
thickness » .94 m
At this position, the plume is CONTACTING the RIGHT bank.
Furthermore, the CCC for the toxic pollutant has indeed been met
within the RMZ. In particular:
The CCC was encountered at the following plume position:
The CCC for the toxic pollutant was encountered at the following
plume position:
CCC - 600 PPB
Corresponding dilution = 5.8
Plume location: x » .21 m
(centerline coordinates) y » 7.82 m
z - 2.12m
Plume dimensions: half-width » .10 m
thickness *» .10 m
********************* FINAL DESIGN ADVICE AND COMMENTS **********************
REMINDER: The user must take note that HYDRODYNAMIC MODELING by any known
technique is NOT AN EXACT SCIENCE.
Extensive comparison with field and laboratory data has shown that the
CORMIX predictions on dilutions and concentrations (with associated
plume geometries) are reliable for the majority of cases and are accurate
to within about +-50% (standard deviation) .
As a further safeguard, CORMIX will not give predictions whenever it judges
the design configuration as highly complex and uncertain for prediction.
DESIGN CASE: Summer Stratification
FILE NAME: SAMPLE1
Subsystem C0RMIX1: Submerged Single Port Discharges
END OF SESSION/ITERATION: 08/26/96—05:37:41
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
98
-------
Table B.2
C0RMIX1 Prediction File for A-Plant discharge into Deep Reservoir with summer
stratification
C0RMIX1 PREDICTION FILE:
CORNELL MIXING ZONE EXPERT SYSTEM
Subs
Suk
m CORMIX1:
ed Single Port Discharges
Subsystem version:
CORMIX v.3.1 June 1995
CASE DESCRIPTION
Site name/label:
Design case:
FILE NAME:
Time of Fortran run:
DEEP RESERVOIR
A-PLANTA SUMMERA STRATIFICATION
cormix\sim\SAMPLEl .cxl
06/24/95--22:29:54
ENVIRONMENT PARAMETERS (metric units)
Unbounded section
HA = 35.00 HD = 30.50
UA = .015 F = .010 USTAR =
UW = 2.000 UWSTAR= .2198E-02
Density stratified environment
STRCND= C RHOAM = 997.6240
RHOAS = 996.2053 RHOAB = 999.6072 RHOAH0=
DRHOJ = 2.1813 HINT = 15.50 ES
.52 0 0E-0 3
999.5599 E
.2153E-02
= .773 0E-0 3
DISCHARGE PARAMETERS (metric units)
BANK = RIGHT DISTB = 46.00
DO = .254 AO = .051 HO
THETA = 10.00 SIGMA = 90.00
U0 = 3.020 Q0 = .153
RHOO = 998.2051 DRHOO = .1355E+01 GP0
CO = .350 0E+ 04 CUNITS= PPB
IPOLL =1 KS .000 0E+ 0 0 KD
. 1530E+00
.132 9E-01
= .000 0E+ 0 0
FLUX VARIABLES (metric units)
Q0 = .153 0E+ 0 0 M0 = .4620E+00 JO
Associated length scales (meters)
LQ = .23 LM = 12.4 3 Lm
Lmp
= . 2 034E-02 SIGNJ0 =
4 5.31 Lb
4.94 Lbp
602.57
3 .12
NON-DIMENSIONAL PARAMETERS
FRO = 51.96 R
201 .30
FLOW CLASSIFICATION
1 Flow class (CORMIX1)
1 Applicable layer depth HS =
S3
15 .50
MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS
CO
NTOX =
NSTD =
REGMZ =
REGSPC=
XINT =
. 3500E+04
1
1
1
2
3500.00
CUNITS= PPM
CMC = . 12 0 0E+ 04
CSTD = .600 0E+ 0 3
XREG =
XMAX =
.00
3500.00
12 0.0 0 AREG =
X-Y-Z COORDINATE SYSTEM:
ORIGIN is located at the bottom and below the center of the port:
46.00 m from the RIGHT bank/shore.
X-axis points downstream, Y-axis points to left, Z-axis points upward.
NSTEP = 20 display intervals per module
BEGIN MODI01: DISCHARGE MODULE
X
.00
Y
.00
Z
.60
S C
1.0 .350E+04
B
. 13
END OF MODI01: DISCHARGE MODULE
BEGIN CORJET (MOD110): JET/PLUME NEAR-FIELD MIXING REGION
99
-------
Jet-like motion in linear stratification with weak crossflow.
Zone of flow establishment: THETAE= 10.00 SIGMAE = 89.45
LE = 1.25 XE = .01 YE = 1.23 ZE = .82
Profile definitions:
B = Gaussian 1/e (37%) half-width, normal to trajectory
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
X
Y
Z
S
C
B
.00
.00
.60
1 . 0
. 350E+04
. 13
. 01
1.23
. 82
1 . 0
. 350E+04
. 14
. 02
2 .30
1 . 01
1 . 7
. 2 0 5E+ 04
.26
. 04
3 .48
1.23
2 . 6
. 136E+04
.39
** CMC HAS BEEN FOUND **
The pollutant concentration in the plume falls below CMC value of .120E+04
in the current prediction interval.
This is the extent of the TOXIC DILUTION ZONE.
.08 4.67 1.45 3.5 .101E+04 .53
.13 5.97 1.72 4.4 .790E+03 .67
.18 7.14 1.97 5.3 .658E+03 .80
** WATER QUALITY STANDARD OR CCC HAS BEEN FOUND **
The pollutant concentration in the plume falls below water quality standard
or CCC value of .600E+03 in the current prediction interval.
This is the spatial extent of concentrations exceeding the water quality
standard or CCC value.
.24
8 . 32
2 .24
6.2
. 564E + 03
. 94
. 32
9.49
2 . 52
7.1
. 4 93E+ 0 3
1 . 07
.40
10 .65
2 .81
8.0
.437E+03
1.21
.49
11 . 82
3 .10
8.9
. 393E+03
1 . 34
.60
12 . 99
3 .39
9.8
. 357E+03
1.48
. 71
14 .15
3 .66
10.7
. 328E+03
1 .61
. 84
15 .33
3 . 90
11 . 6
. 303E+03
1 . 75
. 98
16 . 51
4 .09
12 .4
.281E+03
1 .89
1 .13
17 .70
4 .23
13 . 3
. 262E+03
2 . 03
1.27
18 . 77
4 .29
14 .2
. 247E+03
2 .15
Maximum jet
height
has been
reached.
1.45
19 . 96
4 .27
15 .1
. 232E+03
2 .29
1 .63
21 .15
4 .16
16 .1
. 218E+03
2 .43
1 .83
22 . 32
3 . 97
17 .1
.205E+03
2 . 57
2 . 04
23 .48
3 . 72
18 .1
. 193E+03
2 . 71
2 .26
24 .63
3 .44
19.1
. 183E+03
2 .85
Terminal level in stratified ambient has been reached.
Cumulative travel time = 63. sec
END OF CORJET (MOD110): JET/PLUME NEAR-FIELD MIXING REGION
7 . 64
m
1.29
m
90 .24
m
-87 . 99
m
1.29
m
191 .87
m
. 95
m
BEGIN MOD137: TERMINAL LAYER INJECTION/UPSTREAM SPREADING
UPSTREAM INTRUSION PROPERTIES:
Maximum elevation of jet/plume rise
Layer thickness in impingement region
Upstream intrusion length
X-position of upstream stagnation point =
Thickness in intrusion region
Half-width at downstream end
Thickness at downstream end
Control volume inflow:
X Y Z S C B
2.26 24.63 3.44 19.1 .183E+03 2.85
Profile definitions:
BV = top-hat thickness, measured vertically
BH = top-hat half-width, measured horizontally in Y-direction
ZU = upper plume boundary (Z-coordinate)
ZL = lower plume boundary (Z-coordinate)
S = hydrodynamic average (bulk) dilution
C = average (bulk) concentration (includes reaction effects, if any)
X
Y
Z
S
C
BV
BH
ZU
ZL
-87 . 99
24 .63
3 .44
9999 . 9
. 000E+00
.00
.00
3 .44
3 .44
CO
24 .63
3 .44
75 .2
. 465E+02
.33
27 .13
3 .60
3 .27
-66 . 02
24 .63
3 .44
31 . 3
. 112E+03
.79
65 . 91
3 .83
3 . 04
100
-------
-47 . 77
24 .63
3 .44
23 .8
. 147E+03
1. 04
89 .17
3 .
. 96
2 . 92
-29.53
24 .63
3 .44
20 . 8
. 169E+03
1.19
107 . 51
4 .
. 03
2 . 84
-11.28
24 .63
3 .44
19.4
. 180E+03
1.28
123 .15
4 .
. 07
2 .80
6 . 96
24 .63
3 .44
19 . 3
. 181E+03
1.29
137 . 02
4 .
. 08
2 .79
25.21
24 .63
3 .44
22 . 5
. 155E+03
1 .22
149 . 61
4 .
. 05
2 . 82
43 .45
24 .63
3 .44
27 . 7
. 126E+03
1 .11
161 .21
3 .
. 99
2 .88
61 .70
24 .63
3 .44
32 .1
. 109E+03
1 . 02
172 . 04
3 .
. 95
2 . 93
79 . 95
24 .63
3 .44
34 .4
. 102E+03
. 97
182 .22
3 .
. 92
2 . 95
98 .19
24 .63
3 .44
35 . 6
. 982E+02
. 95
191 .87
3 .
. 91
2 . 96
lulative
travel
time =
6459
. sec
END OF MOD137: TERMINAL LAYER INJECTION/UPSTREAM SPREADING
** End of NEAR-FIELD REGION (NFR) **
In this design case, the discharge is located CLOSE TO BANK/SHORE.
Some boundary interaction occurs at end of near-field.
This may be related to a design case with a very LOW AMBIENT VELOCITY.
The dilution values in one or more of the preceding zones may be too high.
Carefully evaluate results in near-field and check degree of interaction.
Consider locating outfall further away from bank or shore.
In the next prediction module, the plume centerline will be set
to follow the bank/shore.
** REGULATORY MIXING ZONE BOUNDARY is within the Near-Field Region (NFR) **
BEGIN MOD142: BUOYANT TERMINAL LAYER SPREADING
Plume is ATTACHED to RIGHT bank/shore.
Plume width is now determined from RIGHT bank/shore.
Profile definitions:
BV = top-hat thickness, measured vertically
BH = top-hat half-width, measured horizontally in Y-direction
ZU = upper plume boundary (Z-coordinate)
ZL = lower plume boundary (Z-coordinate)
S = hydrodynamic average (bulk) dilution
C = average (bulk) concentration (includes reaction effects, if any)
Plume Stage 2 (bank attached):
X
Y
z
S
C
BV
BH
ZU
ZL
CO
I-1
-46
.00
3 .44
35 . 6
. 982E+02
1 .38
262 .50
4 .13
2 . 74
268 .28
-46
.00
3 .44
42 . 7
. 820E+02
. 93
468 .27
3 . 90
2 . 97
438 .37
-46
.00
3 .44
48 .4
. 722E+02
.81
609 . 62
3 . 84
3 . 03
608 .46
-46
.00
3 .44
54 . 7
. 640E+02
. 77
728 .17
3 . 82
3 . 05
778 . 55
-46
.00
3 .44
61 . 7
. 568E+02
. 75
836 .14
3 .81
3 . 06
948 . 64
-46
.00
3 .44
69.2
. 505E+02
. 75
938 .66
3 .81
3 . 06
1118 . 73
-46
.00
3 .44
77 . 3
. 453E+02
. 76
1038 .24
3 . 82
3 . 06
1288 . 82
-46
.00
3 .44
85 . 9
. 4 0 8E+ 02
. 77
1136 .20
3 . 82
3 . 05
1458.91
-46
.00
3 .44
94 . 8
. 369E+02
. 78
1233 .26
3 .83
3 . 04
1629 . 00
-46
.00
3 .44
104 . 0
. 336E+02
.80
1329 . 86
3 . 84
3 . 04
1799 .10
-46
.00
3 .44
113 . 6
. 308E+02
.81
1426 .23
3 . 84
3 . 03
1969 .19
-46
.00
3 .44
123 .4
. 284E+02
.83
1522 . 53
3 .85
3 . 02
2139 .28
-46
.00
3 .44
133 . 5
. 262E+02
. 84
1618 .85
3 .86
3 . 02
2309.37
-46
.00
3 .44
143 . 8
. 243E+02
.86
1715.24
3 .86
3 . 01
2479 .46
-46
.00
3 .44
154 .4
. 227E+02
.87
1811 . 74
3 .87
3 .00
2649 . 55
-46
.00
3 .44
165 .2
. 212E+02
.88
1908.37
3 .88
2 . 99
2819.64
-46
.00
3 .44
176 .2
. 199E+02
. 90
2005 .12
3 .88
2 . 99
2989.73
-46
.00
3 .44
187 .4
. 187E+02
. 91
2102.02
3 .89
2 . 98
3159.82
-46
.00
3 .44
198 . 7
. 176E+02
. 92
2199.06
3 . 90
2 . 98
3329 . 91
-46
.00
3 .44
210 . 3
. 166E+02
. 93
2296.24
3 . 90
2 . 97
3500.00
-46
.00
3 .44
222 .1
. 158E+02
. 95
2393.56
3 . 91
2 . 96
Cumulative travel time = 233246. sec
Simulation limit based on maximum specified distance = 3500.00 m.
This is the REGION OF INTEREST limitation.
END OF MOD142: BUOYANT TERMINAL LAYER SPREADING
CORMIX1: Submerged Single Port Discharges End of Prediction File
101
-------
OEEP-RESERUOtR
A-PLANT-SUMMER^STRATtFICATION
¦3o
nK«
O
ai
* o
f
-90 -«0
Distortion = 2.990
CORMEXl Prediction
File:sim\SAHPLEl .cxl
Side Uieu
90
X <«) -
(a)
OEEP-RESERUOIR C0RMIX1 Prediction
A-PLANT^SUMIIER^STRATIFI CATION File: sim\SAMPLEl cxt
-T3i 2 _
ssQ |
(b)
0EEP~RESERU0[R CORMIXI Prediction
A-PLANT~SUMMER-STRATIFICATION File: sim\SAMPLEl .cxl
1*1 5
36
—i * * '—i—i—«—"—i—i—i— —i—.—i—i—,—.—i—.—i—jf
-00 -40 0 40 80 120
, ... p'3" Dis' (in) —•
Side Uieu Along Plan Trajectoru
distortion = 1.000
(C)
Figure B.4: Different side views of near-field jet/plume discharge in stratified reservoir, a) distorted un-
sealed view, b) view with fixed undistorted scale, and c) undistorted view along trajectory (in the x-y
plane).
102
-------
DEEP-RESERUOIR
A-PLANT~SUt1MER~STRATr Fl CATION
CORMtXl Prediction
File: sim\SAf1PLEl .cxl
Distortion = 1.000
Plan Uieu
(a)
DEEP-RESERUOIR
A-PLANT~SUf1f1E R~ST R A TIFIC A T10 N
C0RI1IXI Prediction
File: sim\SAMPlEl .cxl
Plan Uieu
Oistortion = 1.000
X («)
(b)
Figure B.5: Plan view of diffuser plume in a) complete field (near- and far), and b) near-field only.
(Note: since in this simulation the discharge was schematized as an unbounded cross-section, the
resulting plume would actually contact far shoreline when the plume width exceeds the actual cross-
section width of 1000 m. This occurs when BH = 1000 m at x = 1000 m downstream as shown in view a).
Thus, if plume concentration data were required after far shoreline contact, a bounded cross-section
would need to be specified (BS = 1000) in a new simulation.
103
-------
OEEP^RESERUOIR CORMIX1 Prediction
A-PLANT~SUMMERaSTRATIFICATION File: sim\Sft!1PLEl . cxl
Figure B.6: Concentration distribution as a function of distance along plume centerline
a few parameters such as the upstream intrusion
length, downstream width, and shape of the
intrusion. As indicated in Figure B.5, reasonable
transition boundaries can be assumed to provide
smooth transitions to the far-field processes.
The side and plan views show the wide
and thin layer that forms as the plume collapses
laterally within the ambient stratification while it is
advected by the weak ambient flow.
Some discontinuity in the predicted
plume dimensions occurs in the transition from
the control volume (MOD137) describing
upstream spreading to the continuous prediction
for ambient buoyant spreading (MOD142). The
cause for this discontinuity is the simultaneous
interaction of the plume with the channel
boundary that occurs within MOD137.
CORMIX1 detects such complicated
simultaneous processes and warns the user who
then can compensate by providing reasonable,
mass-conserving transitions.
It is also possible to include
concentration values, e.g. along the centerline, in
plots of this type. This has not been done in
these figures in order not to overload them.
Alternatively, the concentration distribution
following the centerline of the plume is plotted in
Figure B.6. The rapid drop-off within the initial
buoyant jet region is evident. Also, the
thresholds for all water quality parameters and
module boundaries have been exercised in the
plot. Hence, the locations where the CMC (i.e.
TDZ) and CCC values are met have been
indicated.
B.5 Details of Buoyant Jet Near-field Mixing
The CORJET model option can be
employed if further details within the very initial
buoyant jet motion are desired. This option can
be exercised internally at the conclusion of the
CORMIX design case by choosing the post-
processor. The CORJET output corresponding
to this has already been shown as an example in
104
-------
Section 6.1, namely as Table 6.2. That output
agrees well with that listed in Table B.2.
More importantly, CORJET could also be
used separately to examine different
approximations to the ambient density profile
and/or velocity distribution. The reader is
encouraged to explore this approach, following
the procedures explained in Section 6.1 and
illustrated in Appendix E.
105
-------
&
106
-------
Appendix C
C0RMIX1 and 2: Submerged Single Port Discharge
and Multiport Diffuser in a Shallow River
The design modification of an existing
(hypothetical situation) discharge from a plant into
a shallow river is considered in this case study.
This affords an opportunity to demonstrate the
joint use of CORMIX and of a dye field study in
order to analyze an existing effluent plume from a
single port discharge and to suggest a design
conversion to a multiport diffuser with improved
mixing characteristics.
C.1 Problem Statement
An industrial plant (B-Plant) is currently
discharging its effluent into an adjacent shallow
river. The design flowrate is quite small at 2.1
mgd (~ 0.092 m3/s). The river is about 200 to 300
ft wide at the discharge location and the following
downstream reach. Water depth is, of course,
dependent on the river discharge that is
seasonally variable. An examination of available
streamflow records (USGS data) suggests a
7Q10 low flow discharge of 285 cfs (~ 8.06 m3/s).
Recent water quality studies in the
discharge reach performed during low flow
summer conditions have shown occasional
coloration problems in the discharge plume that
seem to be related to inadequate mixing
characteristics of the present submerged single
port discharge. For that reason the plant operator
is considering an improvement of the discharge
structure.
C.2 Existing Single Port Discharge: Dye Field
Study and CORMIX1 Comparison
An initial field study was conducted in
order (1) to measure the geometric and hydraulic
characteristics of the discharge reach with special
emphasis on the first 1000 ft downstream, and (2)
to determine plume concentrations by means of a
dye injection into the plant effluent.
Figure C.1 shows the plan geometry of
the discharge reach. River cross-sections were
determined by depth measurements at several
stations as indicated. For example, Figure C.2
gives the cross-section at the discharge location.
All cross-sections exhibit quite some non-
uniformity as is typical for a gently meandering
alluvial (gravel) river. The indicated water level
corresponds to the river discharge of 840 cfs (~
23.7 m3/s) that was measured during the field
survey using the usual USGS stream-gaging
methods. The ambient temperature at this
flowrate was 20 °C. The discharge pipe (diameter
= 8 in ~ 0.2 m) is located about 95 ft from the right
bank, and is pointing in the downstream direction.
In order to obtain a detailed description of
the flow field in the river, reach discharge
measurements were conducted at several more
downstream stations (200, 400, 750, and 1000 ft,
respectively). Figure C.1 includes the cumulative
discharge isolines, expressed in % of the total
discharge as measured from the right bank, for
the reach. These lines provide a useful indication
of the mean flow pattern in such a winding river
for subsequent interpretation of observed plume
features (see also comments on cumulative
discharge method in Section 6.2).
A dye test was carried out by continuously
discharging a fluorescein dye solution into the
plant effluent. The dye concentration exiting the
discharge pipe was 560 ppb with a temperature of
22 °C. Dye concentration were measured at the
transects indicated in Figure C.1, and have been
plotted in Figure C.3 as a function of distance
from the right bank. The observed concentration
profiles show decreasing peak (maximum) values
with increasing downstream distances.
Observations indicated a vertically mixed plume at
all locations. In the display of Figure C.3 the
plume centerline position is clearly shifting relative
to the right bank, and the plume width
occasionally appears to slightlycontract in width.
An initial CORMIX1 evaluation was carried
out to ascertain its applicability in this somewhat
107
-------
B-PLANT
Cumulative
Discharge
50 Existing
Discharge
0 ft Location
Figure C.1: Plan view of downstream reach of Shallow River with cumulative discharge measurement
stations and distribution
Water Level for Discharge
Q - 840 cfs - 23.7 m'/s i
Vertical
Scale
(ft)
165 ft - 50 m—J Right
f-2Q mMl k Bank
Measured
Profile CORMIXP
Schematlzatlon
< 1 1 1 1 h
~Istance 200 100
(ft)
Figure C.2: River cross-section at discharge location
108
-------
Dye
Scale
j 40
•20 ppb
¦¦ 0
A
~ownstream
Distance (ft)
i .1000
1 1 1 « 1
2 SO 200 150 100 SO 0
Distance From
Right Bank (ft)
750
500
400
300
200
100
50
0
Figure C.3: Measured dye concentration plotted as a function of distance from right bank
irregular flow environment. For this purpose, the
cross-section was schematized as a rectangular
cross-section putting emphasis on the depth
conditions around the discharge location. The
average and local depths at this flow rate are both
1.9 ft or (» 0.6 m).
Information from the cumulative discharge
data was used. Note that the cumulative
discharge data shows the discharge located at the
60 % line, i.e. it is hydraulically closer to the left
bank, while it appears geographically closer to the
right! This is reflected in the schematization:
Within the 165 ft (» 50 m) wide rectangular
channel, the discharge is located 20 m from the
left bank. The roughness of the slightly winding,
but otherwise clean natural channel has been
specified by a Manning's n value of 0.03.
Figure C.4 is the data checklist prepared
for the C0RMIX1 session, while Table C.1
represents the detailed C0RMIX1 Prediction File
(the session report is not given here). C0RMIX1
predicts that the plume gets rapidly mixed over the
shallow depth, and is primarily influenced by far-
field mixing processes, a feature that is quite
consistent with observations. The dye
concentration distribution predicted by C0RMIX1
in the schematic rectangular channel are plotted in
Figure C.5 and show a much more regular mixing
pattern than the earlier Figure C.3. However,
matters can be readily reconciled when both field
data and C0RMIX1 predictions are interpreted as
a function of cumulative discharge (for example
by means of the far-field post-processor
FFLOCATR, although the details of the
FFLOCATR application are not shown herein).
This has been done in Figure C.6 where
both distributions are directly superposed on the
cumulative discharge pattern. The agreement is
excellent. This entire procedure points out the
need for high-quality field data if detailed
interpretations and predictions of discharge
plumes are desired.
C.3 Proposed Multiport Diffuser Discharge
Under 7Q10 flow Conditions: CORMIX2
Predictions
The following strategy is pursued in order
109
-------
CHECKLIST FOR DATA PREPARATION
CORMIX -- CORNELL MIXING ZONE EXPERT SYSTEM - Version 3.1,3.2
SITE Name
Design CASE
DOS FILE NAME
Shallow River
Dye T55t
Date:
Prepared by: GHJ
Dve 1
(w/o extension)
AMBIENT DATA:
Water body depth
Depth at discharge
If steady: Ambient flowrate
If tidal:
Tidal period
At time
Water body is
0-6 m If bounded: Width
0.6 m Appearance
23.7 m3/s or: Ambient velocity
_hr Max. tidal velocity
bounded/EKBSMHasa
50 m
_hr before/at/after slack: Tidal velocity at this time
. m/s
. m/s
m/s
Manning's n
Wind speed
Density data:
Water body is
If uniform:
If stratified:
Stratification type
If B/C: Pycnocline height
0.03 or:
2 m/s
Darcy-Weisbach f
fresh/gait water
A/B/C
m
UNITS: Density...kg/m3 / Temperature...°C
If fresh: Specify as danafa/temo. values
Average density/temp. 20.0
Density/temp, at surface
Density/temp, at bottom
If C: Density/temp, jump
DISCHARGE DATA:
Specify geometry for CORMIX1 or 2 or 3
SUBMERGED SINGLE PORT DISCHARGE - CORMIX1
Nearest bank is on left/fioht Distance to nearest bank
Vertical angle THETA 0 0 Horizontal angle SIGMA
Port diameter 0.2 m or: Port area
Port height 0.15 m
?n n m
SUBMERGED MULTIPORT DIFFUSER DISCHARGE - CORMIX2
Nearest bank is on left/right Distance to onej
Diffuser length m ^to-ettter endpoint
Total number of openings
Port diameter -rfTwith contraction ratio
Diffuser arrangement/typy-^" unidirectional / staged / alternating or vertical
Alignmeman^eTS^MMA 0 Horizontal angle SIGMA
~angle THETA 0 Relative orientation BETA
BUOYANT SURFACE DISCHARGE - CORMIX3
Discharge located on
Horizontal angle SIGMA
Depth at discharge
If rectangular
"cHannel: Depth
left/riaht bank
Configurj
ffrudino: Dist. from bank_
Bottom slope
If circular Diameter_
pioe: Bottom invert depth _
I7protrudino/co-fl owing
Effluent: Flow rate
Effluent density
Heated discharge?
Concentration units
Conservative substance?
0.092 m3/s or: Effluent velocity
ko/m3 or: Effluent temperature
ves
-------
Table C.1
C0RMIX1 Prediction File for dye test in Shallow River
CORMIX1 PREDICTION FILE:
CORNELL MIXING ZONE EXPERT SYSTEM
Subsystem (
Submerged
XI:
le Port Discharges
Subsystem version:
CORMIX v.3.10 June 1995
CASE DESCRIPTION
Site name/label:
Design case:
FILE NAME:
Time of Fortran run:
Shallow^River
DyeATest
cormix\sim\dyel .cxl
04/14/96 --11:03:24
ENVIRONMENT PARAMETERS (metric units)
Bounded section
BS = 50.00 AS = 30.00 QA
HA = .60 HD = .60
UA = .790 F = .084 USTAR =
UW = 2.000 UWSTAR= .2198E-02
Uniform density environment
STRCND= U RHOAM = 998.2051
DISCHARGE PARAMETERS (metric units)
BANK = LEFT DISTB = 20.00
DO = .200 AO = .031 HO
THETA = .00 SIGMA = .00
U0 = 2 . 929 Q0 = .092
RHOO = 997.7714 DRHOO = .4337E+00 GP0
CO = .56 0 0E+ 0 3 CUNITS= ppb
IPOLL =1 KS .000 0E+ 0 0
FLUX VARIABLES (metric units)
Q0 = .92 0 0E-01 M0 = .2694E+00
Associated length scales (meters)
LQ = .18 LM = 18.89
NON-DIMENSIONAL PARAMETERS
FRO = 100.31 R
KD
JO
Lm
Lmp
23.70 ICHREG= 2
.808IE-01
. 15
= .92 0 0E-01
= .42 6 0E-02
= .000 0E+ 0 0
= .3 92 0E-0 3 SIGNJ 0 = 1.0
. 6 6 Lb = .00
= 99999.00 Lbp = 99999.00
FLOW CLASSIFICATION
1 Flow class (CORMIX1)
1 Applicable layer depth HS =
H5-0
.60
MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS
CO = .56 0 0E+ 0 3 CUNITS= ppb
NTOX = 0
NSTD = 0
REGMZ = 0
XINT = 10 0 0.00 XMAX = 1000.00
X-Y-Z COORDINATE SYSTEM:
ORIGIN is located at the bottom and below the center of the port:
2 0.00 m from the LEFT bank/shore.
X-axis points downstream, Y-axis points to left, Z-axis points upward.
NSTEP = 20 display intervals per module
BEGIN MODI01: DISCHARGE MODULE
COANDA ATTACHMENT immediately following the discharge.
X
.00
Y
.00
Z
.00
S C B
1.0 .56 0E + 0 3 .14
END OF MODI01: DISCHARGE MODULE
BEGIN CORJET (MOD110): JET/PLUME NEAR-FIELD MIXING REGION
Bottom-attached jet motion.
111
-------
Profile definitions:
B = Gaussian 1/e (37%) half-width, normal to trajectory
Half wall jet, attached to bottom.
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
X
Y
z
s
C
B
.00
.00
.00
1 . 0
. 560E+03
.10
1 . 05
.00
.00
1.2
.483E+03
. 16
2 .10
.00
.00
1 . 7
. 337E+03
.21
3 .15
.00
.00
2 .1
.263E+03
.26
4 .21
.00
.00
2 . 6
. 216E+03
.29
5.26
.00
.00
3 . 0
. 185E+03
. 32
6 .31
.00
.00
3 .4
. 163E+03
.35
7 .36
.00
.00
3 . 8
. 146E+03
.38
8 .41
.00
.00
4 .2
. 132E+03
.40
9.46
.00
.00
4 . 6
. 121E+03
.42
10 . 51
.00
.00
5 . 0
. 112E+03
.44
11 . 56
.00
.00
5 . 3
. 105E+03
.46
12 . 62
.00
.00
5 . 7
. 983E+02
.48
13 .67
.00
.00
6 . 0
. 927E+02
.50
14 . 72
.00
.00
6 .4
. 878E+02
. 51
15 . 77
.00
.00
6 . 7
. 834E+02
. 53
16 . 82
.00
.00
7 . 0
. 795E+02
. 55
17 .87
.00
.00
7.4
. 761E+02
. 56
18 . 92
.00
.00
7 . 7
. 729E+02
. 57
19 . 97
.00
.00
8 . 0
. 701E+02
.59
21 . 03
.00
.00
8 . 3
. 675E+02
.60
Cumulative
travel time
=
14
. sec
END OF CORJET (MOD110): JET/PLUME NEAR-FIELD MIXING REGION
BEGIN MOD133: LAYER BOUNDARY IMPINGEMENT/FULL VERTICAL MIXING
Control volume inflow:
X Y Z S C B
21.03 .00 .00 8.3 .675E+02 .60
Profile definitions:
BV = layer depth (vertically mixed)
BH = top-hat half-width, in horizontal plane normal to trajectory
ZU = upper plume boundary (Z-coordinate)
ZL = lower plume boundary (Z-coordinate)
S = hydrodynamic average (bulk) dilution
C = average (bulk) concentration (includes reaction effects, if any)
X
Y
Z
S
C
BV
BH
ZU
ZL
20 .43
.00
.60
8 . 3
. 675E+02
.00
.00
.60
.60
20 . 55
.00
.60
8 . 3
. 675E+02
.60
. 11
.60
.00
20 .67
.00
.60
8 . 3
. 675E+02
.60
. 15
.60
.00
20 .79
.00
.60
8 . 3
. 675E+02
.60
.19
.60
.00
20 . 91
.00
.60
8 . 3
. 675E+02
.60
.22
.60
.00
21 . 03
.00
.60
8 . 3
. 675E+02
.60
.24
.60
.00
21 .15
.00
.60
8 . 8
. 637E+02
.60
.27
.60
.00
21.27
.00
.60
9 . 9
. 568E+02
.60
.29
.60
.00
21 .39
.00
.60
10 . 8
. 517E+02
.60
.31
.60
.00
21 . 51
.00
.60
11 .4
.4 93E+ 02
.60
.33
.60
.00
21 .63
.00
.60
11 . 6
. 482E+02
.60
.35
.60
.00
Cumulative
travel time
=
15
. sec
END OF MOD133: LAYER BOUNDARY IMPINGEMENT/FULL VERTICAL MIXING
BEGIN MOD153: VERTICALLY MIXED PLUME IN CO-FLOW
Phase 1: Vertically mixed, Phase 2: Re-stratified
Phase 1: The plume is VERTICALLY FULLY MIXED over the entire layer depth.
This flow region is INSIGNIFICANT in spatial extent and will be by-passed.
Phase 2: The flow has RESTRATIFIED at the beginning of this zone.
This flow region is INSIGNIFICANT in spatial extent and will be by-passed.
112
-------
END OF MOD153: VERTICALLY MIXED PLUME IN CO-FLOW
** End of NEAR-FIELD REGION (NFR) **
The initial plume WIDTH values in the next far-field module will be
CORRECTED by a factor 3.25 to conserve the mass flux in the far-fieldi
The correction factor is quite large because of the small ambient velocity
relative to the strong mixing characteristics of the discharge!
This indicates localized RECIRCULATION REGIONS and internal hydraulic JUMPS.
Flow appears highly UNSTEADY and prediction results are UNRELIABLE!
BEGIN M0D141: BUOYANT AMBIENT SPREADING
Discharge is non-buoyant or weakly buoyant.
Therefore BUOYANT SPREADING REGIME is ABSENT.
END OF MOD141: BUOYANT AMBIENT SPREADING
BEGIN MOD161: PASSIVE AMBIENT MIXING IN UNIFORM AMBIENT
Vertical diffusivity (initial value)
Horizontal diffusivity (initial value) =
. 970E-02 mA2/s
. 242E-01 mA2/s
The passive diffusion plume is VERTICALLY FULLY MIXED at beginning of region.
Profile definitions:
BV = Gaussian s.d.*sqrt(pi/2) (46%) thickness, measured vertically
= or equal to layer depth, if fully mixed
BH = Gaussian s.d.*sqrt(pi/2) (46%) half-width,
measured horizontally in Y-direction
ZU = upper plume boundary (Z-coordinate)
ZL = lower plume boundary (Z-coordinate)
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
Plume Stage 1 (not bank attached):
X
Y
z
S
C
BV
BH
ZU
ZL
21 .63
.00
.60
11 . 6
. 482E+02
.60
1 .12
.60
.00
70 . 55
.00
.60
25 . 3
. 222E+02
.60
2 .44
.60
.00
119.47
.00
.60
33 . 8
. 166E+02
.60
3 .26
.60
.00
168 .39
.00
.60
40 . 5
. 138E+02
.60
3 . 92
.60
.00
217.30
.00
.60
46 . 3
. 121E+02
.60
4 .48
.60
.00
266 .22
.00
.60
51 . 5
. 109E+02
.60
4 . 98
.60
.00
315 .14
.00
.60
56 .1
. 998E+01
.60
5.43
.60
.00
364 . 06
.00
.60
60 . 5
. 926E+01
.60
5 . 84
.60
.00
412 . 98
.00
.60
64 . 5
. 869E+01
.60
6 .23
.60
.00
461.90
.00
.60
68 . 3
. 820E+01
.60
6 .60
.60
.00
510 .81
.00
.60
71 . 9
. 779E+01
.60
6 . 95
.60
.00
559.73
.00
.60
75 . 3
. 744E+01
.60
7.28
.60
.00
608 .65
.00
.60
78 . 5
. 713E+01
.60
7 .59
.60
.00
657 . 57
.00
.60
81 . 7
. 686E+01
.60
7 . 90
.60
.00
706 .49
.00
.60
84 . 7
. 661E+01
.60
8 .19
.60
.00
755.41
.00
.60
87 . 6
. 639E+01
.60
8 .47
.60
.00
804 .33
.00
.60
90 .4
. 619E+01
.60
8 . 74
.60
.00
853 .24
.00
.60
93 .2
. 601E+01
.60
9 . 01
.60
.00
902.16
.00
.60
95 . 8
. 584E+01
.60
9.27
.60
.00
951 . 08
.00
.60
98 .4
. 569E+01
.60
9 . 52
.60
.00
1000 .00
.00
.60
101 . 0
. 555E+01
.60
9 . 76
.60
.00
.mulative
travel time
=
1249
. sec
Simulation limit based on maximum specified distance =
This is the REGION OF INTEREST limitation.
1000 .00 m.
END OF MOD161: PASSIVE AMBIENT MIXING IN UNIFORM AMBIENT
CORMIX1: Submerged Single Port Discharges End of Prediction File
113
-------
40
Dye t
Scale -20 ppb
0
Distance From
Right Bank (ft).
Cumulative
Downstream
Distance (ft)
11000
•C
0>
t/%\
150 100 SO
750
500
400
300
200
100
50
, 0
Discharge (%) 100 80 60 40 20 10
Figure C.5: Dye concentrations predicted by C0RMIX1 plotted as a function of distance from right
bank in schematized channel
B-PLANT
— Field Data
- CORMIX1
Prediction
' 40 Oye
Scale
; 20 ppb
. Discharge
Pipe
Figure C.6: Comparison of measured field dye distribution and CORMIX1 predictions within
cumulative discharge pattern
114
-------
to improve the near-field mixing characteristics of
the existing discharge: (1) Utilization of a multiport
diffuser to increase the initial entrainment of
ambient water into the multiple effluent jets, and
(2) shifting of the discharge location toward the
right bank to delay the contact with the left
shoreline that -with the present installation-
seems to occur at a downstream distance of 1000
ft.
The design study is carried out for the low
flow ambient condition given by the 7Q10
discharge (285 cfs -8.1 m3/s) as is typical for
water quality studies on riverine sites.
Temperatures of the discharge and ambient and
channel roughness is assumed unchanged. The
new local and average depth for this flowrate is
calculated to be ~ 0.3 m from the formula given in
Section 4.3.1.
State water quality regulations call for a
demonstration of plume concentrations at the
edge of a mixing zone that is limited to one fourth
(1/4) of the river width. With an average river
width of 250 ft, this corresponds to a width
limitation of 250/4 ~ 62 ft (~ 19 m). (Note: The
actual width limitation must be handled within the
schematized cross-sections as specified. For the
schematic channel width of 50 m this represents
a 19/50 = 38% width limitation specification as
used in CORIMX2.)
Obviously, a number of design solutions,
with different diffuser configurations and
locations, need to be investigated. One of several
feasible solutions is presented in the following: A
15 m (~ 49 ft) long diffuser consisting of 7 nozzles
is installed in perpendicular, co-flowing
arrangement centered at the 40% cumulative
discharge position. (Note: In the actual
coordinate position, this corresponds to a
distance of about 70 ft from the right bank; see
Figure C.1.) The nozzle diameter is 2.5 in (~
0.0635 m).
The CORMIX2 simulation is summarized
in Figure C.7 (data preparation checklist), Table
C.2 (session report), and Table C.3 (prediction
file).
Inspection of the session record and
prediction file shows that the plume becomes
rapidly mixed over the very shallow water depth.
Furthermore, a high initial dilution of 29.8 is
attained in a short region (labeled the
"acceleration zone", MOD271) following the high
velocity multiport discharge. These results are
plotted in Figure C.8 using the graphics package
CMXGRAPH. In order to illustrate the capabilities
of the graphics program these plots include (a)
the un-scaled plan view as it first appears on
screen, (b) a re-scaled plan view that is
undistorted (1:1) to show the actual long and
narrow plume shape and river stretch, and (c) a
side view of the near-field only with 1:2 vertical
distortion. The user should explore the manifold
features of the graphics package.
Obviously, predicted plan plume shapes
should be interpreted with the cumulative
discharge method. The far-field plume locator
FFLOCATR (Section 6.2) is designed for exactly
that purpose. The two data files examples in
Section 6.2 (input: Table 6.4, output: Table 6.5)
are, in fact, applications for the present design
case. Hence, the results of Table 6.5 when
plotted on the river plan view with the cumulative
discharge isolines are shown in Figure C.9 and
exhibit realistic plume shapes. After the rapid
initial mixing in the near-field the plume is growing
only very slowly in the far-field (MOD261). At the
1000 ft transect, the plume stays clear of the left
bank.
The concentration distribution along the
plume centerline is plotted in Figure C. 10 for the
near-field only, as very slow additional mixing
occurs at larger distances (see Table C.3). As
regards the regulatory mixing zone (RMZ) the
prediction results indicate that it will be
encountered at a considerable distance
downstream, at about 354 m (~ 1200 ft), i.e.
outside the region plotted in Figure C.10. The
dilution at that location is 33.5, corresponding to
a local centerline concentration value of 3.0 %.
Finally, it is illuminating to compare the
performance of the proposed multiport diffuser
design with the existing single port situation, both
under 7Q10 low flow. This is also included in
Figure C.10 by plotting the plume centerline
concentrations. (Note: The data sheet, session
record, and output file for this CORMIX1
application are omitted for space reasons.)
Clearly, the multiport design achieves much more
-------
rapid initial mixing by capturing more of the
ambient entrainment flow as the diffuser is spread
over portion of the river width. Figure C.10 also
includes an additional CORMIX1 prediction for a
single plume out of the 7-nozzle arrangement to
provide more detail in the near-field; the user has
been prompted by several messages within
CORMIX2 to perform this additional prediction.
116
-------
CHECKLIST FOR DATA PREPARATION
CORMIX - CORNELL MIXING ZONE EXPERT SYSTEM - Version 3.1,3.2
SITE Name
Design CASE
DOS FILE NAME
B-Plant Shallow River
Low I- low /giu
Sample 2
Date:
Prepared by: GHJ
(w/o extension)
AMBIENT DATA:
Water body depth
Depth at discharge
If steady: Ambient flowrate
0.3 m
0-3 m
8.1 m3/s or:
Water body is bounded/nwhaMwdad
If bounded: Width 50 m
Appearance *1213
Ambient velocity m/s
hr
If tidal: Tidal period
At time hr before/at/after slack:
Manning's n
Wind speed
Density data:
Water body is
If uniform:
If stratified:
Stratification type
If B/C: Pycnocline height
0.03 or:
2 m/s
Max. tidal velocity
Tidal velocity at this time
Darcy-Weisbach f
i m/s
m/s
fresh/ga(t water
A/B/C
m
UNITS: Density...kg/m3 / Temperature...°C
If fresh: Specify as
-------
Table C.2
CORMIX Session Report for B-Plant discharge into Shallow River with multiport diffuser
CORMIX SESSION REPORT:
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
CORMIX: CORNELL MIXING ZONB EXPERT SYSTEM
CORMIX v.3.10 June 1995
SITE NAME/LABEL: B-PLANT SHALLOW-RIVER
DESIGN CASE: LOW-FLOW 7Q10
FILE NAME: SAMPLE2
Using subsystem CORMIX2: Submerged Multiport Diffuser Discharges
Start of session: 06/24/95--22:3S:06
*****************************************************************************
SUMMARY OF INPUT DATA:
AMBIENT PARAMETERS:
Cross-section
Width
Channe1 regulari ty
Ambient flowrate
Average depth
Depth at discharge
Ambient velocity
Darcy-Weisbach friction factor
Calculated from Manning's n
Wind velocity
Stratification Type
Surface temperature
Bottom temperature
Calculated FRESH-WATER DENSITY values:
Surface density RHOAS
Bottom density RHOAB
= bounded
BS
ICHREG = 2
QA
HA
HD
UA = 0.
F = 0.
UW
STRCND = U
998
998
SO . 0 m
8.1 mA3/s
0.30m
0.30 m
.5400 m/s
.1054
0 . 03
2 m/s
20.0 degC
2 0.0 degC
.2051 kg/mA3
.2051 kg/mA3
DISCHARGE PARAMETERS:
Diffuser type
Diffuser length LD
Nearest bank
Diffuser endpoints YB1
Number of openings NOPEN
Spacing between risers/openings SPAC
Port/Nozzle diameter DO
Equivalent slot width B0
Total area of openings AO
Discharge velocity U0
Total discharge flowrate Q0
Discharge port height HO
Nozzle arrangement
Diffuser alignment angle GAMMA
Vertical discharge angle THETA
Horizontal discharge angle SIGMA
Relative orientation angle BETA
Discharge temperature (freshwater)
Submerged Multiport Diffuser Discharge
DITYPE = unidirectional perpendicular
= 15.0
= right
m; YB2 =
7
-2.50 m
.0635 m
.0014 m
.0031 mA2
4.14 m/s
0.092 mA3/s
0 . 09 m
Corresponding density RHOO
Density difference DRHO
Buoyant acceleration GP0
Discharge concentration CO
Surface heat exchange coeff. KS
Coefficient of decay KD
BETYPE = unidirectional without fanning
90 deg
0 deg
0 deg
90 deg
22.0 degC
997.7714 kg/mA3
0.4336 kg/mA3
.0043 m/sA2
100 PERCENT
0 m/s
0 /s
FLUX VARIABLES PER UNIT DIFFUSER LENGTH:
Discharge (volume flux) q0
Momentum flux m0
Buoyancy flux jo
0.006133 mA2/s
0.025452 mA3/sA2
0.000026 mA3/sA3
DISCHARGE/ENVIRONMENT LENGTH SCALES :
lq = 0.00 m lm = 0.08 m 1M = 28.80 m
lm' = 99999.0 m lb' = 99999.0 m la = 99999.0 m
(These refer to the actual discharge/environment length scales.)
NON-DIMENSIONAL PARAMETERS:
Slot Froude number FRO = 1653.66
Port/nozzle Froude number FRD0 = 252.28
Velocity ratio R = 7.68
MIXING ZONE / TOXIC DILUTION ZONE / AREA OF INTEREST PARAMETERS:
Toxic discharge - no
Water quality standard specified = no
Regulatory mixing zone « yes
Regulatory mixing zone specification » width
Regulatory mixing zone value ='
Region of interest =
19 m (mA2 if area)
1000.00 m
118
-------
*****************************************************************************
HYDRODYNAMIC CLASSIFICATION:
* *
| FLOW CLASS = MU2 |
* *
This flow configuration applies to a layer corresponding to the full water
depth at the discharge site.
Applicable layer depth = water depth = 0.30 m
*****************************************************************************
MIXING ZONE EVALUATION (hydrodynamic and regulatory summary):
X-Y-Z Coordinate system:
Origin is located at the bottom below the port center:
20 m from the right bank/shore.
Number of display steps NSTEP = 20 per module.
NEAR-FIELD REGION (NFR) CONDITIONS :
Note: The NFR is the zone of strong initial mixing. It has no regulatory
implication. However, this information may be useful for the discharge
designer because the mixing in the NFR is usually sensitive to the
discharge design conditions.
Pollutant concentration at edae of NFR = 3.3538 PERCENT
(centerline coordinates) y = .00 m
z = .30m
NFR plume dimensions: half-width = 6.73 m
thickness a .30 m
Buoyancy assessment:
The effluent density is less than the surrounding ambient water
density at the discharge level.
Therefore, the effluent is POSITIVELY BUOYANT and will tend to rise towards
the surface.
Near-field instability behavior:
The diffuser flow will experience instabilities with full vertical mixing
in the near-field.
There may be benthic impact of high pollutant concentrations.
FAR-FIELD MIXING SUMMARY:
Plume becomes vertically fully mixed ALREADY IN NEAR-FIELD at 7.50 m
downstream and continues as vertically mixed into the far-field.
************************ TOXIC DILUTION ZONE SUMMARY ************************
No TDZ was specified for this simulation.
********************** REGULATORY MIXING ZONE SUMMARY ***********************
The plume conditions at the boundary of the specified RMZ are as follows:
Pollutant concentration = 2.955534 PERCENT
Corresponding dilution = 33.8
Plume location: x = 3 84.55 m
(centerline coordinates) y = .00 m
z = .30m
Plume dimensions: half-width = 9.50 m
thickness = .30 m
********************* FINAL DESIGN ADVICE AND COMMENTS **********************
CORMIX2 uses the TWO-DIMENSIONAL SLOT DIFFUSER CONCEPT to represent
the actual three-dimensional diffuser geometry. Thus, it approximates
the details of the merging process of the individual jets from each
port/nozzle.
In the present design, the spacing between adjacent ports/nozzles
(or riser assemblies) is somewhat greater (in the range between
three times to ten times) the local water depth. It is unlikely
that sufficient lateral interaction of adjacent jets will
occur in the near-field. However, the individual jets/plumes may merge
soon after in the intermediate-field or in the far-field.
C0RMIX2 may have LIMITED APPLICABILITY for this discharge situation.
The results may be somewhat unrealistic in the near-field (minimum
dilution may be overpredicted), but appear to be applicable for the
intermediate- and far-field processes.
The user is advised to use a subsequent C0RMIX1 (single port discharge)
analysis, using discharge data for an individual diffuser jet/plume,
in order to compare to the present near-field prediction.
REMINDER: The user must take note that HYDRODYNAMIC MODELING by any known
technique is NOT AN EXACT SCIENCE.
Extensive comparison with field and laboratory data has shown that the
CORMIX predictions on dilutions and concentrations (with associated
plume geometries) are reliable for the majority of cases and are accurate
to within about +-50% (standard deviation).
As a further safeguard, CORMIX will not give predictions whenever it judges
the design configuration as highly complex and uncertain for prediction.
*****************************************************************************
DESIGN CASE: LOW-FLOW 7Q10
FILE NAME: SAMPLE2
Subsystem CORMIX2: Submerged Multiport Diffuser Discharges
END OF SESSION/ITERATION: 04/14/96--XI:16:37
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
119
-------
Table C.3
C0RMIX2 Prediction File for B-Plant discharge into Shallow River with multiport diffuser
CORMIX2 PREDICTION FILE:
22222222222222222222222222222222222222222222222222222222222222222222222222222
CORNELL MIXING ZONE EXPERT SYSTEM
Subsystem CORMIX2: Subsystem version:
Submerged Multiport Diffuser Discharges CORMIX_v.3.00 July_1994
CASE DESCRIPTION
Site name/label:
Design case:
FILE NAME:
Time of Fortran run:
B-PLANT SHALLOW-RIVER
LOW-FLOWa7Q10
cormix\sim\SAMPLE2 .cx2
06/24/95--22:36:15
ENVIRONMENT PARAMETERS (metric units)
Bounded section
BS = 50.00 AS = 15.00 QA
HA = .30 HD = .30
UA = .54 OF = .105 USTAR =
UW = 2.000 UWSTAR= .2198E-02
Uniform density environment
STRCND= U RHOAM = 998.2051
8.10 ICHREG= 2
.6199E-01
DIFFUSER DISCHARGE PARAMETERS (metric units)
Diffuser type: DITYPE= unidirectional_perpendicular
BANK =
LD
DO
RIGHT DISTB
15.0 0 NOPEN
.064 AO
20.00 YB1 = 12.50
7 SPAC = 2.50
.003 HO .09
YB2
Nozzle/port arrangement:
GAMMA = 9 0.00 THETA
U0 = 4.150 Q0
RHOO = 997.7714 DRHOO
CO = .10 0 0E+ 0 3
IPOLL = 1
unidirectional_without_fanning
.00 SIGMA = .00
.092 = .92 0 0E-01
= .433 7E+ 0 0 GP0 = .4260E-02
CUNITS= PERCENT
KS = .000 0E+ 0 0 KD = .0000E+00
BETA =
27 .50
90 .00
FLUX VARIABLES - PER UNIT DIFFUSER LENGTH (metric units)
qO = .6133E-02 mO = .2545E-01 jO = .2613E-04
Associated 2-d length scales (meters)
1Q=B = .001 1M = 28.81 lm = .09
Imp = 99999.00 lbp = 99999.00 la = 99999.00
SIGNJ 0 =
1 . 0
FLUX VARIABLES - ENTIRE DIFFUSER (metric units)
Q0 = .92 0 0E-01 M0 = .3818E+00 JO
Associated 3-d length scales (meters)
LQ = .15 LM = 24.53 Lm
Lmp
= .3 92 0E-0 3
1.14
99999 .00
Lb
Lbp
.00
= 99999.00
NON-DIMENSIONAL PARAMETERS
FRO = 1653.66 FRD0 = 252.2
(slot) (port/nozzle)
8 R
7 .66
FLOW CLASSIFICATION
222222222222222222222222222222222222222222
2 Flow class (CORMIX2) = MU2 2
2 Applicable layer depth HS = .30 2
222222222222222222222222222222222222222222
MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS
CO = .10 0 0E+ 0 3 CUNITS= PERCENT
NTOX = 0
NSTD = 0
REGMZ = 1
REGSPC= 2 XREG = .00 WREG = 19.00 AREG = .0(
XINT = 10 0 0.00 XMAX = 1000.00
X-Y-Z COORDINATE SYSTEM:
ORIGIN is located at the bottom and the diffuser mid-point:
2 0.00 m from the RIGHT bank/shore.
X-axis points downstream, Y-axis points to left, Z-axis points upward.
NSTEP = 20 display intervals per module
BEGIN MOD201: DIFFUSER DISCHARGE MODULE
120
-------
Due to complex near-field motions: EQUIVALENT SLOT DIFFUSER (2-D) GEOMETRY
Profile definitions:
BV = Gaussian 1/e (37%) half-width, in vertical plane normal to trajectory
BH = top-hat half-width, in horizontal plane normal to trajectory
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
X Y Z S C BV BH
.00 .00 .09 1.0 .100E+03 .00 7.50
END OF MOD201: DIFFUSER DISCHARGE MODULE
BEGIN MOD2 71: ACCELERATION ZONE OF UNIDIRECTIONAL CO-FLOWING DIFFUSER
In this laterally contracting zone the diffuser plume becomes VERTICALLY FULLY
MIXED over the entire layer depth (HS = .30m).
Full mixing is achieved after a plume distance of about five
layer depths from the diffuser.
Profile definitions:
BV = layer depth (vertically mixed)
BH = top-hat half-width, in horizontal plane normal to trajectory
S = hydrodynamic average (bulk) dilution
C = average (bulk) concentration (includes reaction effects, if any)
X
Y
z
S
C
BV
BH
.00
.00
.09
1 . 0
. 100E+03
.00
7 .50
.38
.00
.09
11 .2
. 894E+01
. 08
7 .39
. 75
.00
.10
15 .4
. 649E+01
. 15
7 .30
1 .13
.00
.10
18 . 6
. 536E+01
.23
7 .22
1 .50
.00
.10
21.4
.468E+01
.30
7 .15
1 .88
.00
. 11
23 . 8
. 42 0E+ 01
.30
7 .09
2 .25
.00
. 11
26 . 0
. 385E+01
.30
7 . 04
2 .63
.00
. 11
28 . 0
. 358E+01
.30
6 . 99
3 .00
.00
. 11
29 . 8
. 335E+01
.30
6 . 95
3 .38
.00
. 12
29 . 8
. 335E+01
.30
6 . 91
3 . 75
.00
. 12
29 . 8
. 335E+01
.30
6 .87
4 .13
.00
. 12
29 . 8
. 335E+01
.30
6 . 84
4 .50
.00
. 13
29 . 8
. 335E+01
.30
6 . 82
CO
CO
.00
. 13
29 . 8
. 335E+01
.30
6 .80
5.25
.00
. 13
29 . 8
. 335E+01
.30
6 . 78
5 .63
.00
. 14
29 . 8
. 335E+01
.30
6 . 76
o
o
.00
. 14
29 . 8
. 335E+01
.30
6 . 75
CO
ro
.00
. 14
29 . 8
. 335E+01
.30
6 . 74
6 . 75
.00
. 14
29 . 8
. 335E+01
.30
6 . 74
7 .13
.00
. 15
29 . 8
. 335E+01
.30
6 . 74
7 .50
.00
. 15
29 . 8
. 335E+01
.30
6 . 73
Cumulative
travel time
=
11
. sec
END OF MOD2 71: ACCELERATION ZONE OF UNIDIRECTIONAL CO-FLOWING DIFFUSER
BEGIN MOD2 51: DIFFUSER PLUME IN CO-FLOW
Phase 1: Vertically mixed, Phase 2: Re-stratified
Phase 1: The diffuser plume is VERTICALLY FULLY MIXED over the
entire layer depth.
This flow region is INSIGNIFICANT in spatial extent and will be by-passed.
Phase 2: The flow has RESTRATIFIED at the beginning of this zone.
This flow region is INSIGNIFICANT in spatial extent and will be by-passed.
END OF MOD2 51: DIFFUSER PLUME IN CO-FLOW
** End of NEAR-FIELD REGION (NFR) **
The initial plume WIDTH values in the next far-field module will be
CORRECTED by a factor 1.24 to conserve the mass flux in the far-fieldi
BEGIN MOD241: BUOYANT AMBIENT SPREADING
Discharge is non-buoyant or weakly buoyant.
Therefore BUOYANT SPREADING REGIME is ABSENT.
121
-------
END OF MOD241: BUOYANT AMBIENT SPREADING
BEGIN MOD261: PASSIVE AMBIENT MIXING IN UNIFORM AMBIENT
Vertical diffusivity (initial value) = .372E-02 mA2/s
Horizontal diffusivity (initial value) = .930E-02 mA2/s
The passive diffusion plume is VERTICALLY FULLY MIXED at beginning of region.
Profile definitions:
BV = Gaussian s.d.*sqrt(pi/2) (46%) thickness, measured vertically
= or equal to layer depth, if fully mixed
BH = Gaussian s.d.*sqrt(pi/2) (46%) half-width,
measured horizontally in Y-direction
ZU = upper plume boundary (Z-coordinate)
ZL = lower plume boundary (Z-coordinate)
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
Plume Stage 1 (not bank attached):
X
Y
Z
S
C
BV
BH
ZU
ZL
7 .50
.00
.30
29 . 8
. 335E+01
.30
8 .37
.30
.00
57 .13
.00
.30
30 .4
. 329E+01
.30
8 . 53
.30
.00
106 . 75
.00
.30
30 . 9
. 323E+01
.30
CO
CO
.30
.00
156 .38
.00
.30
31 . 5
. 318E+01
.30
ro
CO
CO
.30
.00
206 .00
.00
.30
32 . 0
. 313E+01
.30
CO
CO
.30
.00
255 .63
.00
.30
32 . 5
. 308E+01
.30
9 .13
.30
.00
305.25
.00
.30
33 . 0
. 303E+01
.30
9.27
.30
.00
354 .88
.00
.30
33 . 5
. 2 98E+ 01
.30
9 .42
.30
.00
** REGULATORY MIXING ZONE BOUNDARY **
In this prediction interval the TOTAL plume width meets or exceeds
the regulatory value = 19.00 m.
This is the extent of the REGULATORY MIXING ZONE.
404 .50
.00
.30
34 . 0
. 2 94E+ 01
.30
9 . 56
.30
.00
454 .13
.00
.30
34 . 5
.290E+01
.30
9 .69
.30
.00
503.75
.00
.30
35 . 0
.286E+01
.30
9 .83
.30
.00
553 .38
.00
.30
35 . 5
. 282E+01
.30
9 . 96
.30
.00
603 .00
.00
.30
36 . 0
. 278E+ 01
.30
10 .10
.30
.00
652 .63
.00
.30
36 .4
.275E+01
.30
10 .23
.30
.00
702 .25
.00
.30
36 . 9
. 271E+01
.30
10 .36
.30
.00
751 .88
.00
.30
37 . 3
.268E+01
.30
10 .48
.30
.00
801 .50
.00
.30
37 . 8
.265E+01
.30
10 .61
.30
.00
851 .13
.00
.30
38 .2
. 262E+01
.30
10 . 73
.30
.00
900 . 75
.00
.30
38 . 7
.259E+01
.30
10 .86
.30
.00
950 .38
.00
.30
39 .1
. 256E+01
.30
10 . 98
.30
.00
1000 .00
.00
.30
39 . 5
. 253E+01
.30
11 .10
.30
.00
Cumulative
travel time
=
1828
. sec
Simulation limit based on maximum specified distance = 1000.00 m.
This is the REGION OF INTEREST limitation.
END OF MOD261: PASSIVE AMBIENT MIXING IN UNIFORM AMBIENT
Because of the fairly LARGE SPACING between adjacent risers/nozzles/ports,
the above results may be unreliable in the immediate near-field of
the diffuser.
A SUBSEQUENT APPLICATION OF CORMIX1 IS RECOMMENDED to provide more detail
for one of the individual jets/plumes in the initial region
before merging.
CORMIX2: Submerged Multiport Diffuser Discharges End of Prediction File
22222222222222222222222222222222222222222222222222222222222222222222222222222
122
-------
B-PLANT-SHALLOU-RIUER
LOU-FLOIWBIO
CQRMIX2 Prediction
File: sim\SAt1PLE2 .cx2
£
8*nk/shor* Uft
I
200
I1
400
Bank/shore right
600
800
Distortion = 10.983
Plan ULeu
(a)
X (n)
1000
B-PLANT~SHALLOU-RIUER C0RMIX2 Prediction
LOU-FLOIWQIO FiLe: sim\SAMPLE2 .cx2
Stag
Rantr / Plan Uieu
Distortion = 1.00
(b)
B-PLANT-SHALLOU-RIUER
LOU-FLOIWQIO
C0RMIX2 Prediction
File:sim\SAMPLE2 .cx2
:1&
IN <3X0 1.5
Distortion = 2.000
3.0
Side Uieu
4.5
Bottom
I
6.0
X (m)
7.5
(c)
Figure C.8: CORMIX2 prediction for B-Plant multiport diffuser discharge in Shallow River. Examples
of different graphics plots: a) Plan view over entire reach, b) equivalent undistorted plan view, and c) side
view of near-field only.
123
-------
B-PLANT
40 Pollutant
Cone
.Diffuser
(7 nozzles)
Figure C.9: Results of cumulative discharge interpretation of C0RMIX2 prediction for B-Plant multiport
diffuser discharge in Shallow River
20
Plume 15;
Centerllne -• y
Concentration
(%) 10+
CORMIX2 Prediction for
Prooosed 7-Nozzle Multiport
Diffuser
CORMIX1 Prediction for Plume
From One Nozzle of Multiport
Diffuser
CORMIX1 Prediction for Existing
Single Port Discharge
\
\
5 \
• \
H 1 1 h
1 1 1 1 1 >
^ 200 400 600 800 1000
Zone of Distance
Merging Along Plume
(ft)
Figure C. 10: Predicted plume centerline concentrations for multiport diffuser design (CORMIX1) in
comparison to single port design (CORMIX2)
124
-------
Appendix D
C0RMIX3: Buoyant Surface Discharge In An Estuary
Estuarine conditions are characterized by
highly variable ambient conditions during the tidal
cycle. This case study provides a short
application example for a buoyant surface
discharge from a large manufacturing plant
discharging its process water into an estuary.
D.1 Problem Statement
A manufacturing plant (C-Plant) is using
process water at a capacity of 2.2 m3/s (~ 50
mgd). The process water is essentially fresh
water with a discharge temperature of 20.0 °C
and contains copper at a concentration of 80 |jg/l.
The plant is located at the shore of an
estuary. Figure D.1 shows the bottom bathymetry
at the plant location; two transects have been
measured and show a relatively rapid drop-off
from the MSL line to a depth of about 5 m below
MSL. It is proposed to build a discharge channel
with a bottom elevation of about 1.0 m below MSL
and a width of 2.0 m. Thus, given the tidal
variation at the discharge location indicated in
Figure D.1, the actual channel depth will vary from
a maximum of about 1.8 m at MHW to a minimum
of about 0.5 at MLW, with corresponding
adjustments in the discharge velocity.
Figure D.2 shows data from
oceanographic field surveys near the discharge
site with ambient velocity variations from about
+0.7 m/s for flood tide and to about -0.7 m/s for
ebb tide. Figure D.2 also shows the tidal
elevation variations from -.7 m above MLW at ebb
to +1.1 m above MLW at flood. The estuary has
brackish water with mean salinity of about 26 ppt,
yielding a density of about 1018 kg/m3 (see Figure
4.3 as an aid).
State regulations specify a mixing zone of
about 250 m extending in any direction from the
discharge point. The CMC and CCC values for
copper are 25 and 15 |jg/l, respectively.
D.2 Steady State Simulation (for reference)
Although it is to be expected that the
surface discharge plume for this situation will be
quite variable in appearance and mixing
characteristics due to the tidal reversal, a steady
state simulation will be performed to illustrate the
basic CORMIX3 application in a time invariant
ambient receiving water. Furthermore, this
simulation will be used as a basis for comparison
in the next selection, where tidal CORMIX
simulations are appropriately performed in order
to determine the time evolution in this highly
unsteady environment.
Assume that the conditions one hour after
low water slack tide (t = 11.7 h) represent that in
a large steady river (see condition (b), Figure
D.2). This design condition is represented by a
water level 0.35 m below MSL and an ambient
velocity of 0.22 m/s. As shown in Figure D.1, the
ambient water body is schematized as
unbounded, with an average depth of 6 m at MSL,
a local depth of 2.5 m at MSL (1.5 m below the
discharge channel mouth), and a bottom slope of
11°.
Figure D.3 presents the input data
checklist and Table D.1 shows the CORMIX3
prediction file (the session report is omitted here
for brevity) for the steady state reference
condition one hour after low water slack (LWS).
The shallow discharge channel (depth of 0.65 m)
produces a relatively weak free jet (flow class
FJ1). After only 4.5 m offshore distance, the initial
jet momentum is overwhelmed by the high
discharge buoyancy, and forms a surface plume
which is weakly deflected by the ambient
crossflow (MOD313). In this region, buoyant
forces rapidly thin and spread the plume
horizontally. Both the CCC and CMC are met
within this region, (and also within the regulatory
mixing zone) as is displayed by CORMIX in the
prediction file. The plume then becomes strongly
deflected (MOD323) and finally contacts the
shoreline some 1560 m downstream. The plume
then becomes attached to the shoreline, and
spreads through passive ambient diffusion and
weak buoyant forces (MOD341), until the end of
the region of interest (2000 m). Figure D.4 shows
the above behavior.
125
-------
DIst. +2 ••
From
MSL
(m)
0 ¦-
-2 --
-6--
4- Bottom of
-4 -- Discharge
4- Channel , v
CORMIX3>
Schematization
\
100
MHW
-MSL
MLW
6.0 m Actual Offshore Topography
Transect I y Transect II
200
300
Distance
Offshore
(m)
Figure D.1: Bathymetric conditions in Estuary in vicinity of C-Plant surface discharge
Figure D.2: Oceanographic data for Estuary showing tidal elevation and current. A complete tidal
analysis might include simulations for all time instances labeled a to g.
126
-------
CHECKLIST FOR DATA PREPARATION
CORMIX - CORNELL MIXING ZONE EXPERT SYSTEM - Version 3.10
SITE Name
Design CASE
DOS FILE NAME
P-P lanr Fsrnai-y
Sreadv Srars - 1 hr. after slack
Samplel (w/o extension)
Date:
Prepared by: RLQ
AMBIENT DATA:
Water body depth
Depth at discharge
If steady: Ambient flowrate
5.65 m
JlJ£ m
m3/s or
Water body is feaunxlexl/unbounded
If bounded: Width m
Appearance d&ISx
Ambient velocity n m/s
hr
Iktidak Tidal period
At time hr before/at/after slack:
Max. tidal velocity .
Tidal velocity at this time
Manning's n
Wind speed
Density data:
Water body is
If uniform:
If stratified:
Stratification type
If B/C: Pycnocline height
m/s
or Darcy-Weisbach f
n
. m/s
m/s
fresh/salt water
AJBIC
m
UNITS: Density...kg/m5 / Temperature..,3C
If fresh: Specify as densitv/tefrav-iwakies
Average density/temp. inn n
Density/temp, at surface -V :
Density/temp, at bottom : •.
If C: Density/terns, jump
DISCHARGE DATA:
Specify geometry for CORMIX1 or 2 or 3
SUBMERGED SINGLE PORT DISCHARGE - CORMIX1
Nearest bank is on left/right ^___Dislaose-WTiearest bank
Vertical angle THETA _—— Horizontal angle SIGMA
Part diameter ——— m or Port area
m
SUBMERGED MULTIPORT DIFFUSER DISCHARGE - CORMIX2
Nearest bank is on left/right Distance to one f
Diffuser length m ^^^^io-ettterendpoint
Total number of openings xvL~-~-—P®rfheight
Port diameter „—-fffwith contraction ratio
Diffuser arrancemgntflygg'" unidirectional / staged / alternating or vertical
AlignmentaflgteTlAMMA 3 Horizontal angle SIGMA
angle THETA 3 Relative orientation BETA
BUOYANT SURFACE DISCHARGE - CORMIX3
Discharge located on
Horizontal angle SIGMA
Depth at discharge
If rectangular Width
discharge channel: Depth
?tsft/rioht bank
90_
m
m
m
2.15
or
n
Configuration flush/arotmiibuaitasrftow^ffg
If protruding: Dist. from bank m
Bottom slope 11 3
If circular Diameter m
pipe: Bottom invert depth m
Effluent: Flow rate
Effluent density
Heated discharge?
Concentration units
Conseo/ative substance?
2. 2 m3/s or Effluent velocity
_kg/m3 or Effluent temperature
If yes: Heat loss coefficient
Effluent concentration
If no: Decay coefficient
jraa/no
mug-p-L
ves ina.
22
_an.
m/s
"°C
_ W/m2,"C
/day
MIXING ZONE DATA:
Is effluent toxic? ves/oa
WQ stand./conventional poll.? .ves/no
Any mixing zone specified? ves/no-
25
CCC 15
If yes: CMC
If yes: value of standard
If yes: distance 7sn m or width % or m
or area - % or m2
Region of interest
2000
m Grid intervals for display
20
Figure D.3: Data preparation checklist for CORMIX3 steady-state simulation for C-Plant
estuary discharge
127
-------
Table D.1
C0RMIX3 Prediction Steady-Sate Prediction File for Surface Buoyant Discharge
CORMIX3 PREDICTION FILE:
33333333333333333333333333333333333333333333333333333333333333333333333333333
CORNELL MIXING ZONE EXPERT SYSTEM
Subsystem CORMIX3: Subsystem version:
Buoyant Su:
m
Discharges CORMIX_v. 3 .10 June_1995
CASE DESCRIPTION
Site name/label: C-PLANTAESTUARY
Design case: STEADYaSIMULATIONaONEaHOURaAFTERaSLACK
FILE NAME: cormix\sim\SAMPLE3 .cx3
Time of Fortran run: 06/24/95--22 : 32 : 20
ENVIRONMENT PARAMETERS (metric units)
Unbounded section
HA = 5.65 HD = 5.65
UA = .220 F = .025 USTAR = .1230E-01
UW = 2.000 UWSTAR= .2198E-02
Uniform density environment
STRCND= U RHOAM = 1018.0000
DISCHARGE PARAMETERS (metric units)
BANK = RIGHT DISTB = .00 Configuration: flush_discharge
SIGMA = 90.00 HD0 = 2.15 SLOPE = 11.00
Rectangular channel geometry:
B0 = 2.000 HO = .650 AO = .1300E+01 AR
U0 = 1.692 Q0 = 2.200 = .2200E+01
RHOO = 998.2051 DRHOO = .1979E+02 GP0 = .1907E+00
CO = .800 0E+ 02 CUNITS= MUG-P-L
IPOLL =1 KS .000 0E+ 0 0 KD = .0000E+00
FLUX VARIABLES (metric units)
Q0 = .22 0 0E+ 01 M0 = .3723E+01 JO = .4195E+00
Associated length scales (meters)
LQ = 1.14 LM = 4.14 Lm = 8.77 Lb
NON-DIMENSIONAL PARAMETERS
FRO = 3.62 FRCH = 4.80 R = 7.69
FLOW CLASSIFICATION
333333333333333333333333333333333333333333
3 Flow class (CORMIX3) = FJ1 3
3 Applicable layer depth HS = 5.65 3
333333333333333333333333333333333333333333
MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS
CO = .800 0E+ 02 CUNITS= MUG-P-L
NTOX = 1 CMC = .250 0E+ 02 CCC = CSTD
NSTD = 1 CSTD = .15 0 0E+ 02
REGMZ = 1
REGSPC= 1 XREG = 250.00 WREG = .00 AREG =
XINT = 2000.00 XMAX = 2000.00
X-Y-Z COORDINATE SYSTEM:
ORIGIN is located at the WATER SURFACE and at center of discharge
channel/outlet: .00 m from the RIGHT bank/shore.
X-axis points downstream
Y-axis points to left as seen by an observer looking downstream
Z-axis points vertically upward (in CORMIX3, all values Z = 0.00)
NSTEP = 20 display intervals per module
TRJBUO TRJATT TRJBND TRJNBY TRJCOR DILCOR
C 3.401 1.000 1.000 1.000 3.400 1.000
BEGIN MOD301: DISCHARGE MODULE
Efflux conditions:
X Y Z S C BV BH
.00 .00 0.00 1.0 .8 0 0E+ 02 .65 1.00
END OF MOD301: DISCHARGE MODULE
128
-------
BEGIN MOD302: ZONE OF FLOW ESTABLISHMENT
Control volume inflow:
X Y Z S C BV BH
.00 .00 0.00 1.0 .8 0 0E+ 02 .65 1.00
Profile definitions:
BV = Gaussian 1/e (37%) vertical thickness
BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
Control volume outflow:
X Y Z S C BV BH
.13 4.11 0.00 1.4 .576E+02 1.09 1.41
Cumulative travel time = 2. sec
END OF MOD302: ZONE OF FLOW ESTABLISHMENT
BEGIN MOD311: WEAKLY DEFLECTED JET (3-D)
Surface JET into a crossflow
Profile definitions:
BV = Gaussian 1/e (37%) vertical thickness
BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
X
Y
Z
s
C
BV
BH
. 13
4 .11
0
.00
1.4
. 576E+02
1.28
1 .65
. 13
4 .14
0
.00
1.4
. 575E+02
1.28
1 .66
. 13
4 .16
0
.00
1.4
. 574E+02
1.28
1 .66
. 13
4 .18
0
.00
1.4
. 573E+02
1.28
1 .66
. 13
4 .20
0
.00
1.4
. 572E+02
1.29
1 .66
. 14
4 .23
0
.00
1.4
. 571E+02
1.29
1 .67
. 14
4 .25
0
.00
1.4
. 570E+02
1.29
1 .67
. 14
4 .27
0
.00
1.4
. 569E+02
1.29
1 .67
. 14
4 .29
0
.00
1.4
. 568E+02
1 .30
1 .67
. 15
4 . 32
0
.00
1.4
. 567E+02
1 .30
1 .68
. 15
4 . 34
0
.00
1.4
. 566E+02
1 .30
1 .68
. 15
4 .36
0
.00
1.4
. 565E+02
1 .30
1 .68
. 15
CO
ro
0
.00
1.4
. 564E+02
1 .30
1 .68
. 15
4 .41
0
.00
1.4
. 563E+02
1 .31
1 .69
. 16
4 .43
0
.00
1.4
. 562E+02
1 .31
1 .69
. 16
4 .45
0
.00
1.4
. 561E+02
1 .31
1 .69
. 16
4 .47
0
.00
1.4
. 560E+02
1 .31
1 .69
. 16
4 .50
0
.00
1.4
. 559E+02
1 . 32
1 .70
. 17
4 . 52
0
.00
1.4
. 558E+02
1 . 32
1 .70
. 17
4 . 54
0
.00
1.4
. 558E+02
1 . 32
1 .70
. 17
4 . 56
0
.00
1.4
. 557E+02
1 . 32
1 .70
Cumulative travel time = 3. sec
END OF MOD311: WEAKLY DEFLECTED JET (3-D)
BEGIN MOD313: WEAKLY DEFLECTED PLUME
Surface PLUME into a crossflow
Profile definitions:
BV = Gaussian 1/e (37%) vertical thickness
BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
X
Y
Z
s
C
BV
BH
. 17
4 . 56
o
o
o
1.4
. 557E+02
1 . 32
1 .70
.41
6 .86
o
o
o
2 . 3
. 343E+02
. 82
CO
.67
9 .16
o
o
o
2 . 9
. 279E+02
.66
6 . 76
** CMC HAS BEEN FOUND **
The pollutant concentration in the plume falls below CMC value of .250E+02
in the current prediction interval.
This is the extent of the TOXIC DILUTION ZONE.
129
-------
96
11 .46
0 .
.00
3 . 3
. 244E+02
. 58
CO
CO
CO
28
13 . 76
0 .
.00
3 . 6
. 22 0E+ 02
. 52
10 . 93
62
16 . 05
0 .
.00
4 . 0
. 2 02E+ 02
.48
12 . 95
99
18 .35
0 .
.00
4 . 3
. 188E+02
.45
14 . 94
38
20 .65
0 .
.00
4 . 5
. 177E+02
.42
16 . 93
80
22 . 95
0 .
.00
4 . 8
. 167E+02
.40
18 . 92
25
25.25
0 .
.00
5 . 0
. 159E+02
.38
20 . 91
72
27 . 54
0 .
.00
5 . 3
. 152E+02
.36
22 . 90
** WATER QUALITY STANDARD OR CCC HAS BEEN FOUND **
The pollutant concentration in the plume falls below water quality standard
or CCC value of .150E+02 in the current prediction interval.
This is the spatial extent of concentrations exceeding the water quality
standard or CCC value.
4 .22
29 .84
0
.00
5 . 5
. 146E+02
.35
24 . 90
4 . 75
32 .14
0
.00
5 . 7
. 140E+02
.33
26 . 92
5 .30
34 .44
0
.00
5 . 9
. 135E+02
. 32
28 . 93
5 .87
36 . 74
0
.00
6 .1
. 131E+02
.31
30 . 96
6 .48
39 . 03
0
.00
6 . 3
. 126E+02
.30
33 .00
7 .11
41 .33
0
.00
6 . 5
. 123E+02
.29
35 . 05
7 . 76
43 .63
0
.00
6 . 7
. 119E+02
.28
37 .11
8 .44
45 . 93
0
.00
6 . 9
. 116E+02
.28
39 .18
9 .15
48 .23
0
.00
7 .1
. 113E+02
.27
41.25
9 .88
50 . 52
0
.00
7.2
. 110E+02
.26
43 . 34
ative
travel
time :
248
. sec
END OF MOD313: WEAKLY DEFLECTED PLUME
BEGIN MOD323: STRONGLY DEFLECTED PLUME
Profile definitions:
BV = top-hat thickness,measured vertically
BH = top-hat half-width, measured horizontally in Y-direction
S = hydrodynamic average (bulk) dilution
C = average (bulk) concentration (includes reaction effects, if any)
X
9 .88
84 .15
158 .42
232 .69
Y
50 . 52
123 .86
154 .39
176 .11
Z
0 .00
0 .00
0 .00
0 .00
S
7.2
7 . 5
7 . 8
8 .1
C
. 110E+02
. 107E+02
. 103E+02
. 985E+01
BV
.26
.23
.22
.22
BH
43 . 34
60 . 96
77 . 07
92 .39
** REGULATORY MIXING ZONE BOUNDARY **
In this prediction interval the plume
the regulatory value = 250.00 m.
This is the extent of the REGULATORY
distance meets or exceeds
306 . 96
381.23
455 .50
529 . 77
604 . 04
678 .31
752 . 58
826 . 84
901 .11
975 .38
1049 . 65
1123 . 92
1198 .18
1272 .45
1346 . 72
1420 . 99
1495 .25
193 .50
208 .23
221 .14
232 .70
243 .21
252 .88
261 .87
270 .29
278 .21
285 .70
292 . 82
299 .61
306 .11
312 . 34
318 . 34
324 .11
329 . 69
0 .00
0 .00
0 .00
0 .00
0 .00
0 .00
0 .00
0 .00
0 .00
0 .00
0 .00
0 .00
0 .00
0 .00
0 .00
0 .00
. 6
. 1
. 8
. 7
. 7
. 9
. 3
. 9
. 7
. 7
. 9
.4
. 1
30 . 0
33 .1
9
9
10
11
12
14
15
17
19
21
24
27
36
40
Cumulative travel time =
.5
.1
7000 .
MIXING ZONE.
934E+01
876E+01
815E+01
750E+01
685E+01
621E+01
560E+01
504E+01
452E+01
406E+01
365E+01
328E+01
295E+01
267E+01
241E+01
219E+01
199E+01
sec
22
23
25
26
28
30
32
34
36
39
41
44
47
50
54
57
61
107 .24
121 . 77
136 . 02
150 . 02
163 . 77
177 .26
190 .49
203 .46
216.17
228 .65
240 . 91
252.95
264 .79
276.45
287 . 93
299.25
END OF MOD323: STRONGLY DEFLECTED PLUME
** End of NEAR-FIELD REGION (NFR) **
BEGIN MOD341: BUOYANT AMBIENT SPREADING
Profile definitions:
BV = top-hat thickness,measured vertically
BH = top-hat half-width, measured horizontally from bank/shoreline
S = hydrodynamic average (bulk) dilution
C = average (bulk) concentration (includes reaction effects, if any)
130
-------
Plume Stage 1 (not bank attached):
X
Y
Z
s
C
BV
BH
1495.25
329.69
o
o
o
40 .1
. 199E+01
.63
319.79
1498.55
329.69
o
o
o
40 . 3
. 199E+01
.63
320 .29
1501 . 84
329.69
o
o
o
40 . 5
. 198E+01
.63
320 .79
1505.13
329.69
o
o
o
40 . 6
. 197E+01
.63
321.29
1508 .42
329.69
o
o
o
40 . 8
. 196E+01
.63
321 .79
1511.72
329.69
o
o
o
41 . 0
. 195E+01
. 64
322 .29
1515.01
329.69
o
o
o
41 .1
. 195E+01
. 64
322.78
1518.30
329.69
o
o
o
41 . 3
. 194E+01
. 64
323 .28
1521.59
329.69
o
o
o
41 . 5
. 193E+01
. 64
323 . 78
1524 .89
329.69
o
o
o
41 . 6
. 192E+01
. 64
324 .27
1528.18
329.69
o
o
o
41 . 8
. 191E+01
. 64
324 . 77
1531.47
329.69
o
o
o
42 . 0
. 191E+01
.65
325 .27
1534.77
329.69
o
o
o
42 .1
. 190E+01
.65
325 . 76
1538.06
329.69
o
o
o
42 . 3
. 189E+01
.65
326 .26
1541.35
329.69
o
o
o
42 . 5
. 188E+01
.65
326 . 75
1544 . 64
329.69
o
o
o
42 . 6
. 188E+01
.65
327.25
1547 . 94
329.69
o
o
o
CO
. 187E+01
.65
327.74
1551 .23
329.69
o
o
o
43 . 0
. 186E+01
.65
328 .23
1554.52
329.69
o
o
o
43 .2
. 185E+01
.66
328 . 73
1557 .81
329.69
o
o
o
43 . 3
. 185E+01
.66
329 .22
1561 .11
329.69
o
o
o
43 . 5
. 184E+01
.66
329 . 71
.mulative
travel
time =
7299
. sec
Plume is ATTACHED to RIGHT bank/shore.
Plume width is now determined from RIGHT bank/shore.
Plume Stage 2 (bank attached):
X
Y
z
s
C
BV
BH
1561.11
.00
0
.00
43 . 5
. 184E+01
.66
659.39
1583 . 05
.00
0
.00
44 . 6
. 179E+01
.67
662 .33
1605 .00
.00
0
.00
45 . 7
. 175E+01
.69
665.27
1626.94
.00
0
.00
46 . 8
. 171E+01
.70
668 .21
1648 .89
.00
0
.00
48 . 0
. 167E+01
. 71
671.16
1670 .83
.00
0
.00
49 .1
. 163E+01
. 73
674 .11
1692 . 78
.00
0
.00
50 . 3
. 159E+01
. 74
677 . 06
1714.72
.00
0
.00
51 .4
. 156E+01
. 76
680 . 01
1736 .66
.00
0
.00
52 . 6
. 152E+01
. 77
682.97
1758 .61
.00
0
.00
53 . 8
. 149E+01
. 78
685 . 92
1780 . 55
.00
0
.00
55 . 0
. 146E+01
.80
688 .88
1802 .50
.00
0
.00
56 .2
. 142E+01
.81
691 .83
1824 .44
.00
0
.00
57 .4
. 139E+01
.83
694.79
1846 .39
.00
0
.00
58 . 6
. 136E+01
. 84
697.75
1868 .33
.00
0
.00
59 . 9
. 134E+01
.85
700 . 71
1890 .28
.00
0
.00
61 .1
. 131E+01
.87
703 .67
1912 .22
.00
0
.00
62 .4
. 128E+01
.88
706 . 62
1934 .17
.00
0
.00
63 . 6
. 126E+01
. 90
709 . 58
1956 .11
.00
0
.00
64 . 9
. 123E+01
. 91
712.54
1978 . 05
.00
0
.00
66 .2
. 121E+01
. 93
715.50
2000 .00
.00
0
.00
67 . 5
. 118E+01
. 94
718 .46
Cumulative
travel
time
=
9294
. sec
Simulation limit based on maximum specified distance = 2000.00 m.
This is the REGION OF INTEREST limitation.
END OF MOD341: BUOYANT AMBIENT SPREADING
CORMIX3: Buoyant Surface Discharges End of Prediction File
33333333333333333333333333333333333333333333333333333333333333333333333333333
131
-------
C-PLANT~ESTUARY C0RMIX3 Prediction
STEAOY-SIMULATION-ONE-HOUR-AFTER-SLACK FiLe: sim\SAMPLE3 .cx3
(a)
C-PLANT^ESTUARY C0RMIX3 Prediction
STEAOY-SIMULATI0N~ONE~HOIIR~AFTER~SLACK File:sim\SAMPLE3 . cx3
(b)
Figure D.4: CORMIX3 prediction of surface discharge from C-Plant into Estuary using a steady-state
simulation, a) Plume shape in near- and far-field, and b) concentration along plume centerline.
132
-------
D.3 Detailed Tidal Simulations
A high variation in both ambient velocity
and tidal elevation occurs during the tidal episode
shown in Figure D.2. The changing water height
produces a discharge velocity which varies from
0.61 m/s (at high water slack) to 2.2 m/s (at low
water slack). When combined with the large
buoyancy flux, this produces flows which change
from momentum dominated jets to highly buoyant
plumes in a short period of time. Simultaneously,
the time-variant ambient velocity (which ranges
from stagnant to 0.75 m/s) produces flows which
are free and unattached at slack tide, yet become
strongly shore-hugging at maximum flood or ebb
currents.
In such highly time-variant ambient
conditions, it is recommended that several
CORMIX predictions be performed at critical
tidal conditions throughout a reversal episode.
These critical tidal conditions are identified as:
1) Shortly after slack tide. Effects of re-
entrainment of discharge from the
previous half-cycle are greatest.
However, the flow is evolving rapidly in
time, causing CORMIX tidal predictions to
be limited in spatial extent. Several
predictions should be made at hourly or
half hourly intervals following the reversal.
2) Maximum flood and ebb currents:
These represent extremes of along-shore
extent and shoreline interaction. Re-
entrainment will be less important at these
times.
For the present scenario, it is suggested that up
to seven simulations be performed at the times
indicated on Figure D.2 by the letters a-g. In the
following section, a detailed simulation is
performed corresponding to time b, one hour after
slack tide. The results are contrasted for that
case to the steady-state assumption simulated in
the preceding.
D.4 Tidal simulation one hour after slack tide
A detailed example of the tidal simulation
capability of CORMIX is presented in this section,
using conditions corresponding to those in
Section D.2 (see Figure D.2, time b). To perform
a CORMIX tidal simulation, four additional pieces
of data are required:
1) the tidal period (usually 12.4 hours for
a semi-diurnal tidal cycle)
2) the time of simulation (in hours relative
to slack tide)
3) the ambient velocity at the time of
simulation
4) the maximum velocity which occurs
during the tidal cycle
From this data, CORMIX calculates the rate of
reversal (dua/dt) and related unsteady length
scales (Lu, Tu, [ L„ ]min , see Table 5.4), and
determines the spatial extent of CORMIX
applicability and the re-entrainment and build-up
caused by the reversal of ambient current. (Note:
If a simulation is performed at slack tide, then the
time of simulation is t = 0 h, and the ambient
velocity is set to ua = 0 m/s.) However, in order to
calculate the reversal rate, CORMIX requires
input of the ambient velocity at an other time near
reversal (for example, at one hour before or after
slack tide). This information is only used to
determine the limit of spatial applicability for the
slack tide simulation.
For this application, the time of simulation
is one hour after slack tide. The ambient velocity
at this time is ua = 0.22 m/s, and the ambient and
discharge channel depths are the same as in
Section D.2. The maximum ambient velocity
during the tidal cycle is 0.75 m/s. For this
simulation, the data preparation checklist is given
in Figure D.5.
Table D.2 lists the CORMIX session report
and Table D.3 the CORMIX3 prediction file for
this tidal application. Two important
consequences are evident when comparing Table
D.3 and Table D.1 (corresponding steady-state
simulation): 1) a concentration build-up in the
near-field, and 2) the termination of the plume
prediction after some distance. The latter
distance is the region over which a reasonably
steady-state plume can establish itself within the
time-varying tidal environment. The theoretical
background for these procedures is given in the
report on recent CORMIX enhancements (8).
133
-------
CHECKLIST FOR DATA PREPARATION
CORMIX - CORNELL MIXING ZONE EXPERT SYSTEM - Version 3.1,3.2
SITE Name
Design CASE
DOS FILE NAME
C-Plant Estuary
Tidal simulation 1 hr after slack
Date:
Prepared by: GHJ
_Sam£le_^T_
(w/o extension)
AMBIENT DATA:
Water body depth
Depth at discharge
If steady: Ambient flowrate
5.65 m
5.65 m
- m3/s or:
Water body is taoiaxufleid/unbounded
If bounded: Width - m
Appearance VZf3.
Ambient velocity - m/s
12.4 hr
If tidal: Tidal period
At time 1-0 hr 83ft*3/at/after slack:
Max. tidal velocity
Tidal velocity at this time
Manning's n
Wind speed
Density data:
Water body is
If uniform:
If stratified:
Stratification type
If B/C: Pycnocline height
or: Darcy-Weisbach f
0.75
TT7ZT
0.025
m/s
m/s
_2 m/s
ftKSWsalt water
A/B/C
UNITS: Density...kg/m3 / Temperature...°C
If fresh: Specify as density/teem values
Average density/tamp. 1018.0
Density/temp, at surface
Density/temp, at bottom
If C: Density/temp, jump
DISCHARGE DATA:
Specify geometry for CORMIX1 or 2 or 3
SUBMERGED SINGLE PORT DISCHARGE
Nearest bank is on left/right
Vertical angle THETA
Port diameter _ m or:
m
- CORMIX1
Tearest bank
Horizontal angle SIGMA
Port area
SUBMERGED MULTIPORT DIFFUSER DISCHARGE - CORMIX2
Nearest bank is on left/riaht Distance to one_§D
Diffuser length m ^Ja-otfierendpoint
Total number of openings m
Port diameter -—rfPwith contraction ratio
Diffuser arranoement/typy~"~~ unidirectional / staged / alternating or vertical
Alignment^ngterGXMMA 0 Horizontal angle SIGMA
angle THETA 0 Relative orientation BETA
BUOYANT SURFACE DISCHARGE - CORMIX3
Discharge located on >q&ft/rioht bank
Horizontal angle SIGMA QO °
Depth at discharge 7.15 m
If rectangular Width 2.0 m or:
discharge channel: Depth 0.65 m
Configuration flush/mxrtPucKaairaflcraantx
If protruding: Dist. from bank m
Bottom slope 11 0
If circular Diameter m
pipe: Bottom invert depth - m
Effluent: Flow rate
Effluent density
Heated discharge?
Concentration units
Conservative substance?
2.20 m3/s or: Effluent velocity
kg/m3 or: Effluent temperature fresh_
yes/no If yes: Heat loss coefficient _
mug-p-L Effluent concentration _
ves/wa If no: Decay coefficient
22.0
80
m/s
"°C
^ W/m2,°C
/day
MIXING ZONE DATA:
Is effluent toxic? ves/wa
WQ stand./conventional poll.? xaa/no
Any mixing zone specified? ves/aa
Region of interest
2000
If yes
If yes
If yes
CMC
25
CCC 15
value of standard _
distance 250 m or width_
or area
% or m
% or m2
m
Grid intervals for display
10
Figure D.5: Data preparation checklist for C-Plant discharge into Estuary design case for
unsteady tidal conditions using CORMIX3
134
-------
Table D.2
CORMIX Session Report for C-Plant discharge into Estuary with unsteady tidal conditions
CORMIX SESSION REPORT:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
CORMIX: CORNELL MIXING ZONE EXPERT SYSTEM
SITE NAME/LABEL:
DESIGN CASE:
FILE NAME:
Using subsystem CORMIX3:
Start of session:
C-PLANT ESTUARY
TIDAL SIMULATION ONE HOUR AFTER SLACK
SAMPLE3T
Buoyant Surface Discharges
06/24/9S--22:33:33
*****************************************************************************
SUMMARY OF INPUT DATA:
AMBIENT PARAMETERS:
Cross-section
Average depth
Depth at discharge
Darcy-Weisbach friction factor
Wind velocity
TIDAL SIMULATION at time
Instantaneous ambient velocity
Maximum tidal velocity
Rate of tidal reversal
Period of reversal
Stratification Type
Surface density
Bottom density
= unbounded
HA
5.65
m
HD «
5 . 65
m
F
.025
UW -
2
m/s
Tsim »
1
hours
UA
.22
m/ s
UaMAX «
.75
m/s
dUA/dt =
0.2200
(m/s)/hour
T
12.4
hours
STRCND « U
RHOAS =
1018
kg/mA3
RHOAB =
1018
kg/mA3
DISCHARGE PARAMETERS:
Discharge located on
Discharge configuration
Distance from bank to outlet
Discharge angle
Depth near discharge outlet
Bottom slope at discharge
Rectangular discharge:
Discharge cross-section area
Discharge channel width
Discharge channel depth
Discharge aspect ratio
Discharge flowrate
Discharge velocity
Buoyant
DISTB
SIGMA
HDO
SLOPE
AO
BO
HO
AR
QO
UO
Discharge temperature (freshwater)
Corresponding density RHOO
Density difference DRHO
Buoyant acceleration GPO
Discharge concentration CO
Surface heat exchange coeff. KS
Coefficient of decay KD
Surface Discharge
; right bank/shoreline
= flush discharge
= 0 . 0 m
= 90 deg
2.15 m
= li deg
1.3000 mA2
= 2 m
* . 65 m
0 .32
2.199990 mA3/s
= 1.69 m/s
s 20 degC
S 998.2051 kg/mA3
19.7948 kg/mA3
.1907 m/sA2
80 MUG-P-L
m/s
/ s
DISCHARGE/ENVIRONMENT LENGTH
LQ = 1.14 m
SCALES:
Lm =
8 . 77 m
Lb =
39.39 m
LM =s 4.13 m
UNSTEADY TIDAL SCALES:
Tu = 0.222 8 hours
Lu
=
39.34 m
Lmin=
2 . 57 m
NON-DIMENSIONAL PARAMETERS:
Densimetric Froude number
Channel densimetric Froude
no.
FRO
FRCH
3 . 62
= 4.80
(based on
(based on
LQ)
HO)
Velocity ratio
R
7.69
MIXING ZONE / TOXIC DILUTION ZONE / AREA OF INTEREST PARAMETERS:
Toxic discharge = yes
CMC concentration CMC = 25 MUG-P-L
CCC concentration CCC = 15 MUG-P-L
Water quality standard = given by CCC value
Regulatory mixing zone = yes
Regulatory mixing zone specification = distance
Regulatory mixing zone value =* 250 m (m 2 if area)
Region of interest = 3500.00 m
*****************************************************************************
HYDRODYNAMIC CLASSIFICATION:
FLOW CLASS
FJ1
*****************************************************************************
MIXING ZONE EVALUATION (hydrodynamic and regulatory summary) :
X-Y-Z Coordinate system:
Origin is located at water surface and at centerline of discharge channel:
0.0m from the right bank/shore.
Number of display steps NSTEP = 20 per module.
135
-------
NEAR-FIELD REGION (NFR) CONDITIONS :
Note: The NFR is the zone of strong initial mixing. It has no regulatory-
implication. However, this information may be useful for the discharge
designer because the mixing in the NFR is usually sensitive to the
discharge design conditions.
Pollutant concentration at edge of NFR = .0000 MUG-P-L
Dilution at edge of NFR s -0
NFR Location: x = .00 m
(centerline coordinates) y = .00 m
z ss .00 m
NFR plume dimensions: half-width s .00 m
thickness = .00 m
UNSTEADY TIDAL ASSESSMENT:
Because of the unsteadiness of the ambient current during the tidal
reversal, CORMIX predictions have been TERMINATED at:
x = 282.05m
y= 187.66m
z » .00m
For this condition AFTER TIDAL REVERSAL, mixed water from the previous
half-cycle becomes re-entrained into the near field of the discharge,
increasing pollutant concentrations compared to steady-state predictions.
A pool of mixed water formed at slack tide will be advected downstream
in this phase.
************************ TOXIC DILUTION ZONE SUMMARY ************************
Recall: The TDZ corresponds to the three (3) criteria issued in the USEPA
Technical Support Document (TSD) for Water Quality-based Toxics Control,
1991 (EPA/505/2-90-001).
Criterion maximum concentration (CMC) = 25 MUG-P-L
Corresponding dilution = 3.2
The CMC was encountered at the following plume position:
Plume location: x = 1.04 m
(centerline coordinates) y = 12.05 m
z = .00m
Plume dimensions: half-width » 9.41 m
thickness = .56 m
CRITERION 1: This location is within 50 times the discharge length scale of
Lq = 1.14 m.
+++++ The discharge length scale TEST for the TDZ has been SATISFIED. ++++++
CRITERION 2: This location is within 5 times the ambient water depth of
HD = 5.65m.
++++++++++ The ambient depth TEST for the TDZ has been SATISFIED.+++++++++++
CRITERION 3: This location is within one tenth the distance of the extent
of the Regulatory Mixing Zone of 250.00 m downstream.
+++++. The Regulatory Mixing Zone TEST for the TDZ has been SATISFIED. ++++++
The diffuser discharge velocity is equal to 1.69 m/s.
This is below the value of 3.0 m/s recommended in the TSD.
*** All three CMC criteria for the TDZ are SATISFIED for this discharge. ***
********************** REGULATORY MIXING ZONE SUMMARY ***********************
The plume conditions at the boundary of the specified RMZ are as follows:
Pollutant concentration = 17.960500 MUG-P-L
Corresponding dilution * 4.4
Plume location: x = 250.00 m
(centerline coordinates) y = 176.10 ra
z = .00m
Plume dimensions: half-width = 95.88 m
thickness = .21 m
At this position, the plume is NOT IN CONTACT with any bank.
However, the CCC for the toxic pollutant has not been met within the RMZ.
In particular:
The CCC was encountered at the following plume position:
The CCC for the toxic pollutant was encountered at the following
plume position:
CCC = 15 MUG-P-L
Corresponding dilution = 5.3
Plume location: x = 6.02 m
(centerline coordinates) y » 37.32 m
z = .00m
Plume dimensions: half-width = 31.48 m
thickness = .30 m
********************* FINAL DESIGN ADVICE AND COMMENTS **********************
REMINDER: The user must take note that HYDRODYNAMIC MODELING by any known
technique is NOT AN EXACT SCIENCE.
Extensive comparison with field and laboratory data has shown that the
CORMIX predictions on dilutions and concentrations (with associated
plume geometries) are reliable for the majority of cases and are accurate
to within about +-50% (standard deviation).
As a further safeguard, CORMIX will not give predictions whenever it judges
the design configuration as highly complex and uncertain for prediction.
*****************************************************************************
DESIGN CASE: TIDAL SIMULATION ONE HOUR AFTER SLACK
FILE NAME: SAMPLE3T
Subsystem C0RMIX3: Buoyant Surface Discharges
END OF SESSION/ITERATION: 04/14/96--11:24:13
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
136
-------
Table D.3
C0RMIX3 Prediction File for C-Plant discharge into Estuary with unsteady tidal conditions
CORMIX3 PREDICTION FILE:
33333333333333333333333333333333333333333333333333333333333333333333333333333
CORNELL MIXING ZONE EXPERT SYSTEM
Subsystem CORMIX3: Subsystem version:
Buoyant Surface Discharges CORMIX_v. 3 .10 June_1995
CASE DESCRIPTION
Site name/label: C-PLANTAESTUARY
Design case: TIDALaSIMULATIONaONEaHOURaAFTERaSLACK
FILE NAME: cormix\sim\SAMPLE3T.cx3
Time of Fortran run: 06/24/95--22:34:03
ENVIRONMENT PARAMETERS (metric units)
Unbounded section
HA = 5.65 HD = 5.65
Tidal Simulation at TIME = 1.000 h
PERIOD= 12.40 h UAmax = .750 dUa/dt= .220 (m/s)/h
UA = .220 F = .025 USTAR = .1230E-01
UW = 2.000 UWSTAR= .2198E-02
Uniform density environment
STRCND= U RHOAM = 1018.0000
DISCHARGE PARAMETERS (metric units)
BANK = RIGHT DISTB = .00 Configuration: flush_discharge
SIGMA = 90.00 HD0 = 2.15 SLOPE = 11.00
Rectangular channel geometry:
B0 = 2.000 HO = .650 AO = .1300E+01 AR = .325
U0 = 1.692 Q0 = 2.200 = .2200E+01
RHOO = 998.2051 DRHOO = .1979E+02 GP0 = .1907E+00
CO = .800 0E+ 02 CUNITS= MUG-P-L
IPOLL =1 KS .000 0E+ 0 0 KD = .0000E+00
FLUX VARIABLES (metric units)
Q0 = .22 0 0E+ 01 M0 = .3723E+01 JO = .4195E+00
Associated length scales (meters)
LQ = 1.14 LM = 4.14 Lm = 8.77 Lb = 3 9.40
Tidal: Tu = .2229 h Lu = 39.347 Lmin = 2.573
NON-DIMENSIONAL PARAMETERS
FRO = 3.62 FRCH = 4.80 R = 7.69
FLOW CLASSIFICATION
333333333333333333333333333333333333333333
3 Flow class (CORMIX3) = FJ1 3
3 Applicable layer depth HS = 5.65 3
333333333333333333333333333333333333333333
MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS
CO = .800 0E+ 02 CUNITS= MUG-P-L
NTOX = 1 CMC = .250 0E+ 02 CCC = CSTD
NSTD = 1 CSTD = .15 0 0E+ 02
REGMZ = 1
REGSPC= 1 XREG = 250.00 WREG = .00 AREG = .00
XINT = 250 0.0 0 XMAX = 350 0.0 0
X-Y-Z COORDINATE SYSTEM:
ORIGIN is located at the WATER SURFACE and at center of discharge
channel/outlet: .00 m from the RIGHT bank/shore.
X-axis points downstream
Y-axis points to left as seen by an observer looking downstream
Z-axis points vertically upward (in CORMIX3, all values Z = 0.00)
NSTEP = 20 display intervals per module
TRJBUO TRJATT TRJBND TRJNBY TRJCOR DILCOR
C 3.401 1.000 1.000 1.000 3.400 1.000
BEGIN MOD301: DISCHARGE MODULE
Efflux conditions:
X Y Z S C BV BH
.00 .00 0.00 1.0 .8 0 0E+ 02 .65 1.00
137
-------
END OF MOD3 01: DISCHARGE MODULE
BEGIN MOD302: ZONE OF FLOW ESTABLISHMENT
Control volume inflow:
X Y Z S C BV BH
.00 .00 0.00 1.0 .8 0 0E+ 02 .65 1.00
Profile definitions:
BV = Gaussian 1/e (37%) vertical thickness
BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
Control volume outflow:
X Y Z S C BV BH
.13 4.11 0.00 1.4 .586E+02 1.09 1.41
Cumulative travel time = 2. sec
END OF MOD302: ZONE OF FLOW ESTABLISHMENT
BEGIN MOD311: WEAKLY DEFLECTED JET (3-D)
Surface JET into a crossflow
Profile definitions:
BV = Gaussian 1/e (37%) vertical thickness
BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
X
Y
Z
s
C
BV
BH
. 13
4 .11
0
.00
1.4
. 586E+02
1.28
1 .65
. 13
4 .14
0
.00
1.4
. 585E+02
1.28
1 .66
. 13
4 .16
0
.00
1.4
. 584E+02
1.28
1 .66
. 13
4 .18
0
.00
1.4
. 583E+02
1.28
1 .66
. 13
4 .20
0
.00
1.4
. 582E+02
1.29
1 .66
. 14
4 .23
0
.00
1.4
. 581E+02
1.29
1 .67
. 14
4 .25
0
.00
1.4
. 580E+02
1.29
1 .67
. 14
4 .27
0
.00
1.4
. 580E+02
1.29
1 .67
. 14
4 .29
0
.00
1.4
. 579E+02
1 .30
1 .67
. 15
4 . 32
0
.00
1.4
. 578E+02
1 .30
1 .68
. 15
4 . 34
0
.00
1.4
. 577E+02
1 .30
1 .68
. 15
4 .36
0
.00
1.4
. 576E+02
1 .30
1 .68
. 15
CO
ro
0
.00
1.4
. 575E+02
1 .30
1 .68
. 15
4 .41
0
.00
1.4
. 574E+02
1 .31
1 .69
. 16
4 .43
0
.00
1.4
. 573E+02
1 .31
1 .69
. 16
4 .45
0
.00
1.4
. 572E+02
1 .31
1 .69
. 16
4 .47
0
.00
1.4
. 571E+02
1 .31
1 .69
. 16
4 .50
0
.00
1.4
. 571E+02
1 . 32
1 .70
. 17
4 . 52
0
.00
1.4
. 570E+02
1 . 32
1 .70
. 17
4 . 54
0
.00
1.4
. 569E+02
1 . 32
1 .70
. 17
4 . 56
0
.00
1.4
. 568E+02
1 . 32
1 .70
Cumulative travel time = 3. sec
END OF MOD311: WEAKLY DEFLECTED JET (3-D)
BEGIN MOD313: WEAKLY DEFLECTED PLUME
Surface PLUME into a crossflow
Profile definitions:
BV = Gaussian 1/e (37%) vertical thickness
BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory
S = hydrodynamic centerline dilution
C = centerline concentration (includes reaction effects, if any)
X
Y
Z
s
C
BV
BH
. 17
4 . 56
o
o
o
1.4
. 568E+02
1 . 32
1 .70
.41
6 .86
o
o
o
2 . 3
. 354E+02
. 82
CO
.67
9 .16
o
o
o
CO
.2 91E+ 02
.66
6 . 76
. 96
11 .46
o
o
o
3 .1
.256E+02
. 58
CO
CO
CO
** CMC HAS BEEN FOUND **
The pollutant concentration in the plume falls below CMC value of .250E+02
138
-------
in the current prediction interval.
This is the extent of the TOXIC DILUTION ZONE.
1.28
13 . 76
0 .
.00
3 .4
. 233E+02
. 52
10 . 93
1 . 62
16 . 05
0 .
.00
3 . 7
. 216E+02
.48
12 . 95
1 . 99
18 .35
0 .
.00
3 . 9
. 2 0 3E+ 02
.45
14 . 94
2 .38
20 .65
0 .
.00
4 .2
. 192E+02
.42
16 . 93
2 .80
22 . 95
0 .
.00
4 .4
. 184E+02
.40
18 . 92
3 .25
25.25
0 .
.00
4 . 5
. 176E+02
.38
20 . 91
3 . 72
27 . 54
0 .
.00
4 . 7
. 170E+02
.36
22 . 90
4 .22
29 . 84
0 .
.00
4 . 9
. 164E+02
.35
24 . 90
4 . 75
32 .14
0 .
.00
5 . 0
. 159E+02
.33
26 . 92
5 .30
34 .44
0 .
.00
5.2
. 155E+02
. 32
28 . 93
5 .87
36 . 74
0 .
.00
5 . 3
. 151E+02
.31
30 . 96
** WATER QUALITY STANDARD OR CCC HAS BEEN FOUND **
The pollutant concentration in the plume falls below water quality standard
or CCC value of .150E+02 in the current prediction interval.
This is the spatial extent of concentrations exceeding the water quality
standard or CCC value.
6 .48
39 . 03
o
o
o
5.4
. 147E+02
.30
33 .00
7 .11
41 .33
0 .00
5 . 6
. 144E+02
.29
35 . 05
7 . 76
43 .63
0 .00
5 . 7
. 141E+02
.28
37 .11
8 .44
45 . 93
0 .00
5 . 8
. 138E+02
.28
39 .18
9 .15
48 .23
0 .00
5 . 9
. 136E+02
.27
41.25
9 .88
50 . 52
0 .00
6 . 0
. 134E+02
.26
43 . 34
Cumulative travel time = 248. sec
END OF MOD313: WEAKLY DEFLECTED PLUME
BEGIN MOD323: STRONGLY DEFLECTED PLUME
Profile definitions:
BV = top-hat thickness,measured vertically
BH = top-hat half-width, measured horizontally in Y-direction
S = hydrodynamic average (bulk) dilution
C = average (bulk) concentration (includes reaction effects, if any)
X Y Z S C BV BH
9.88 50.52 0.00 6.0 .134E+02 .26 43.34
84.15 123.86 0.00 4.9 .163E+02 .23 60.96
158.42 154.39 0.00 4.6 .174E+02 .22 77.07
232.69 176.11 0.00 4.5 .178E+02 .22 92.39
** REGULATORY MIXING ZONE BOUNDARY **
In this prediction interval the plume distance meets or exceeds
the regulatory value = 250.00 m.
This is the extent of the REGULATORY MIXING ZONE.
282.05 187.67 0.00 4.5 .177E+02 .22 102.26
Cumulative travel time = 1485. sec
CORMIX prediction has been TERMINATED at last prediction interval.
Limiting distance due to TIDAL REVERSAL has been reached.
END OF MOD323: STRONGLY DEFLECTED PLUME
CORMIX3: Buoyant Surface Discharges End of Prediction File
33333333333333333333333333333333333333333333333333333333333333333333333333333
The results of the tidal simulations are
shown graphically in Figure D.6. The most
obvious difference in the tidal CORMIX prediction
at this time is that the maximum predicted
downstream distance is limited to 275 m in the x-
direction. Furthermore, a significant increase in
the pollutant concentration (copper) is observed
at the edge of the RMZ (compare Figure D.4b and
D.6b at a distance of 250 m downstream) in the
tidal application as a result of tidal re-entrainment.
As a result, the copper concentration at the RMZ
is 18 |jg/L as opposed to 10 |jg/L for the steady
state simulation, which exceeds the CCC at this
distance.
139
-------
C-PLANT-ESTUARY
TIDAL~SII1ULATI0N~QNE~H0UR~AFTER~SLACK
C0RPIIX3 Prediction
File: sim\SAriPLE3T.cx3
Plan Uieu
250 300
X
-------
Appendix E
Two Applications of CORJET
Two case studies are presented here
illustrating the application of the post-processing
model included within CORMIX, namely CORJET,
the Cornell buoyant jet integral model. As
discussed in Section 6.1 is an important tool for
predicting additional details within the near-field of
a submerged discharge. Both case studies are
included in the normal CORMIX installation
package.
It is repeated here that CORJET, as any
jet integral model, if used alone and by an
inexperienced analyst, is not a safe
methodology for mixing zone analysis. It is
advised to use it only in conjunction with the more
comprehensive CORMIX system. Therefore, in
case of engineering design applications, CORJET
should be employed after prior use of the
expert system CORMIX has indicated that the
buoyant jet will not experience any
instabilities due to shallow water or due to
attachment to boundaries.
E.1 Submerged multiport diffuser in deep
water
A short diffuser consisting of 11 ports and
a total length of 20 m is discharging fresh water at
a temperature of 30 °C into the stratified coastal
ocean. The diffuser ports are each 0.5 m in
diameter and well-rounded in their internal
hydraulic design so that no further exit flow
contraction will occur. The nozzles are oriented
with a vertical angle of 45 0 upward and a
horizontal angle of 450 pointing into the ambient
crossflow (see multiport diffuser definition
diagram, Figures 4.6 and 4.7). The diffuser has
an alignment of 60 0 with respect to the ambient
current. The discharge flow has a concentration
of 100 % of some conservative substance.
Detailed measurements in the water
column give the distribution of temperature,
salinity and current velocity as a function of
vertical distance. The current at each level flows
in the same direction, i.e. along the coastline.
The water depth at the discharge location is of the
order of 30 m.
The CORJET data preparation checklist
for this design case is given as Figure E.1.
Density data is specified in this case via
temperature and salinity. The program computes
internally the actual density distribution using the
full (UNESCO) equation of state. It should be
noted that in case of multiple ambient levels
CORJET assumes outside the specified range
(e.g. above 15 m in this case) that the data are
linearly continued from the last specified interval.
If uniform ambient conditions exist only a single
level must be specified.
The port height HO in the input data
specification is set to 0.0 m; thus, the coordinate
system is conveniently set at the discharge
height. Another value for the actual height above
the water bottom could be used too, but
remember that CORJET, as all integral models,
does not compute actual bottom interaction
effects (see Section 6.1.1). A maximum
computation height of 30 m and distance of 200
m is specified to stop the computation. The
number of print intervals is set to 10, in order to
provide sufficient detail.
A prior application of CORMIX (using a
linear density approximation Type A) has shown
that a stable multiport diffuser flow class MS
results for this case. The reader is encouraged to
ascertain that! Thus, CORJET is indeed
applicable for this case.
Table E.1 shows the input data file as
prepared externally using a line editor. The
CORJET prediction file is shown in Table E.2.
The file echoes the input data, but also lists the
computed density values, and all important
parameters and non-dimensional numbers. Note
that all parameters and scales are referenced to
the values of ambient conditions at the level of
discharge. The second half of the output table
gives the predicted plume conditions.
141
-------
CHECKLIST FOR DATA PREPARATION
CORJET - CORNELL BUOYANT JET INTEGRAL MODEL- Version 4.1
DOS File Name: CASE5MPD. INP Date: 4/12/96
Prepared by: GHJ
Label: Case 5: MULTIPORT DIFFUSER, STRATIFIED, VARIABLE CURRENT
Fluid/Density:
Fluid: 1 (water) Density specification: 1 (via temp./sal.) Number of ambient levels: 3
2XakX (1 to 10)
Ambient Da
Level No.
ta:
Elevation
(m)
Temperature
(°C)
Salinity
(PPt)
Density
(kg/m3)
Velocity
(m/s)
Angle of
velocity (deg)
1
0
12.0
30.0
_
0.5
0
2
5
15.0
29.5
-
0.8
0
3
15
20.0
28.0
-
1.2
0
Discharge Conditions:
Number of openings:
(=1 for single port s.p.)
11
Port
diameter (m)
0.5
Height above
origin (m)
0.0
Exit velocity
(m/s)
3.0
Vertical
angle (deg)
45.0
Horizontal
angle (deg)
45.0
Discharge
conc. (any
units)
100
Coefficient of
decay (/s)
0
Discharge
temp. (°C)
30.0
Discharge
salinity (ppt)
0.0
Discharge
density
(kg/m3)
Diffuser
length (m)
(= 0. if s.p.)
20.0
Alignment
angle (deg)
(= 0. if s.p.)
60.
Program Control:
Max. vertical n Min. vertical n n Max. distance along 9nn _ Print intervals: 1f)
distance (m): • distance (m): trajectory (m): * (best 5 to 10)
Figure E.1: Data preparation checklist for CORJET simulation of multiport diffuser discharge
into stratified coastal waters with arbitrary velocity distribution
142
-------
Table E.1
CORJET input data file for multiport diffuser discharge into stratified coastal waters
#CORJET INPUT FILE
#Title line (5 0 characters max.) :
Case5: MULl —- [RT DIFFUSER: STRATIFIED, VARIABLE CURRENT
—Jr,2=air), Density option (l=calculate,2=specify directly):
Density option (%) : Ambient levels (1-10) :
3
fill in TA+SA; if 2, fill in RHOA):
MUL
#Fluid (1=
#Fluid {%)
1 1
#Ambient conditions (if d.o.=l,
#Level ZA TA SA RHOA UA
1 0. 12. 30. 0.5
2 5. 15. 29.5 0.8
3 15. 20. 28. 1.2
#Discharge conditions (T0+S0, or RHOO
#NOPEN DO HO U0 THETA0 SIGMA0
11 0.50. 3.0 45. 45.
#Program control:
#ZMAX ZMIN DISMAX NPRINT
30 . 0. 200. 10
TAUA
0 .
0 .
0 .
above;
KD
100 . 0 .
if NOPEN=l:
TO SO
30 . 0 .
set LD= 0,ALIGN= 0) :
RHOO LD ALIGN
20 . 60.
Table E.2
CORJET prediction file for multiport diffuser discharge into stratified coastal waters
CORJET PREDICTION FILE:
JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ
CORJET: CORNELL BUOYANT JET INTEGRAL MODEL Version 4.1, April 1996
FILE NAME:
Label/identifier:
Time of CORJET run:
post\cj\case5mpd.OUT
Case5: MULTIPORT DIFFUSER: STRATIFIED, VARIABLE CU
4/13/96--15:56:58
Ambient conditions: No. of levels: 3
LEV ZA TA SA RHOA
1 .00 12 . 00 30 .00 1022 .71
2 5.00 15.00 29.50 1021.74
3 15.00 20.00 28.00 1019.43
Fluid: Water
UA TAUA
.50 .00
.80 .00
1.20 .00
Density option: 1
Discharge conditions (metric): For each port:
DO HO U0 THETA0 SIGMA0 CO
.500 .00 3.00 45.00 45.00 .10E+03
MULTIPORT DIFFUSER conditions:
NOPEN LD SPAC ALIGN QOtotal
11 20.00 2.00 60.00
KD TO
. 0 0E+ 0 30.0
6.480 = .64 8 0E+ 01
SO RHOO
.0 995.65
Program control:
ZMAX ZMIN DISMAX NPRINT
30 .00 .00 200 .00 10
Flux variables (based on ambient at discharge level): For each port:
Q0 = . 58 9E+ 0 0 M0 = .177E+01 JO = .153E+00 GP0 = .259E+00
QT0 = .106E+02 QS0 = -.177E+02
For multiport diffuser (per unit length):
qO = .324E+ 0 0 mO = .972E+00 jO = .841E-01
Length scales (m) and parameters:
LQ
Lmp
.44
5 .61
LM
Lbp
3 . 92
6 . 71
For each port:
Lm
2.66 Lb
1.22
For multiport diffuser
(per unit length):
1Q=B = .108 1M
=
5 . 07
lm
3 .89
lq*
. 74
Imp = 8.16 lbp
=
10 .37
FRO = 8.33 FR02
=
17 . 92
Fa
1 .14
R
o
o
(port) (2-D
i slot)
Zone of flow establishment (m)
LE = 1.3 0 XE
=
. 75
YE
. 62
ZE
.86
THETAE= 38.34 SIGMAE=
o
o
ro
GAMMAE =
49.43
CORJET PREDICTION:
Stepsize =
.2659
Printout every
10
steps
Individual jet/plumes before
merging:
X Y Z
Sc
Cc
B 1
DIST
Save
Gpc
dTc
dSALc
o
o
o
o
o
o
1.0
100E+03
-25 |
.00
1. 0
. 2 6E+ 0 0
18 .
0-30 . 0
.75 .62 .86
1.0
100E+03
-25 |
1 .30
1.4
. 2 7E+ 0 0
20 .
8-34 . 7
2.80 1.50 2.27
3.0
333E+02
. 64 |
3 . 96
4 .6
. 83E-01
5 .
2 -9.9
Merging of
143
-------
Horizontal jet/plume half-width BH = B +
4 .26
5 .31
7 . 96
10 .61
13 .26
15 . 91
18 . 57
21 .22
23 .88
26 . 53
29 .18
31 . 84
34 .49
37 .15
39.80
42 .46
45 .11
47 . 77
50 .43
53 . 08
55 . 74
58 .39
61 . 05
63 . 71
66 .36
69 . 02
71 .68
74 . 34
76 . 99
79 .65
82 .31
84 . 97
87 . 62
90 .28
92 . 94
95 .60
98 .26
100 . 91
103 . 57
106 .23
108 .89
111 . 55
114 .20
116 .86
119 . 52
122 .18
124 . 84
125 . 90
Terminal
1.78
1.84
1.88
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
1 .89
level
2 .85
3 . 01
3 .22
3 .41
3 .59
3 . 77
3 . 94
4 .11
4 .27
4 .43
4 . 58
4 . 73
4 .87
5 . 01
5 .15
5.28
5.41
5 . 53
5 .65
5 . 77
5 .88
5 . 99
6 .09
6 .20
6 .29
6 .39
6 .48
6 . 57
6 .65
6 . 74
6 .81
6 .89
6 . 96
7 . 03
7 .09
7 .16
7 .22
7.27
7 .33
7 .38
7.43
7.47
7 . 51
7 . 55
7 .59
7 . 62
7 .65
7 .66
4 . 5
6 . 3
7.4
8 .4
9 . 5
10 . 6
11 . 7
12 . 8
13 . 9
15 .1
16 .2
17 .2
18 . 3
19.4
20 . 5
21 . 5
22 . 6
23 . 6
24 . 6
25 . 6
26 . 5
27 . 5
28 .4
29 . 3
30 .1
31 . 0
31 . 8
32 . 6
33 . 3
34 .1
34 . 8
35 . 5
36 .1
36 . 7
37 . 3
37 . 8
38 . 3
38 . 8
39.2
39 . 6
40 . 0
40 . 3
40 . 6
40 . 8
41 . 0
41 .1
41.2
41.2
in stratified
. 223E + 02
. 159E+02
. 136E+02
. 118E+02
. 105E+02
. 940E+01
. 852E+01
. 779E+01
. 717E+01
. 664E+01
. 619E+01
. 580E+01
. 545E+01
. 515E+01
488E+01
. 464E+01
. 443E+01
. 424E+01
407E+01
. 391E+01
. 377E+01
. 364E+01
. 352E+01
. 342E+01
. 332E+01
. 323E+01
. 315E+01
. 307E+01
. 300E+01
293E+01
287E+01
. 282E+01
. 277E+01
. 272E+01
268E+01
. 264E+01
261E+01
. 258E+01
. 255E+01
252E+01
250E+01
. 248E+01
. 246E+01
. 245E+01
. 244E+01
. 243E+01
. 243E+01
. 243E+01
ambient
1.
1.
1.
1.
1.
1.
2 .
2 .
2 .
2 .
2 .
3 .
3 .
3 .
3 .
3 .
3 .
3 .
4 .
4 .
4 .
4 .
4 .
4 .
4 .
4 .
5 .
5 .
5 .
5 .
5 .
5 .
5 .
5 .
5 .
5 .
5 .
5 .
6 .
6 .
6 .
6 .
6 .
6 .
6 .
6 .
has
10 .00
5 . 55
6 . 62
9.27
11 . 93
14 .59
17 .25
19 . 91
22 . 57
25.23
27 .89
30 . 54
33 .20
35 .86
38 . 52
41 .18
43 . 84
46 .50
49 .15
51 .81
54 .47
57 .13
59 .79
62 .45
65 .11
67 . 77
70 .42
73 . 08
75 . 74
78 .40
81 . 06
83 . 72
86 .38
89 . 03
91 .69
94 .35
97 . 01
99 .67
102 .33
104 . 99
107 .65
110.30
112.96
115 . 62
118 .28
120 . 94
123 .60
126 .26
127 . 32
6 . 6
6 .4
7 . 5
8 . 6
9 . 7
10 . 7
11 . 8
12 . 9
14 . 0
15 .1
16 .1
17 .2
18 .2
19 . 3
20 . 3
21.4
22 .4
23 .4
24 . 3
25 . 3
26 .2
27 .1
28 . 0
28 . 9
29 . 7
30 . 5
31 . 3
32 .1
32 . 8
33 . 5
34 .2
34 . 9
35 . 5
36 .1
36 . 6
37 .1
37 . 6
38 .1
38 . 5
38 . 9
39.2
39 . 5
39 . 8
40 . 0
40 .2
40 . 3
40 . 3
40 . 3
been reached.
. 54E-01
. 38E-01
. 32E-01
. 28E-01
. 24E-01
. 21E-01
. 19E-01
.17E-01
. 15E-01
. 14E-01
.13E-01
. 12E-01
. 11E-01
. 97E-02
.8 9E-02
.82E-02
. 75E-02
.6 9E-02
.63E-02
. 58E-02
. 54E-02
.4 9E-02
.45E-02
. 42E-02
.38E-02
. 35E-02
. 32E-02
.2 9E-02
.27E-02
. 24E-02
.22E-02
.20E-02
. 18E-02
. 16E-02
. 14E-02
. 12E-02
. 11E-02
. 93E-03
.80E-03
. 67E-03
. 56E-03
. 45E-03
. 35E-03
. 26E-03
. 17E-03
. 94E-04
. 23E-04
PROGRAM STOPS 1
3 .1
-6 . 5
2 .1
-4 . 7
1 . 6
-3 . 9
1 . 3
-3 .4
1 .1
-3 . 0
. 8
-2 . 7
. 6
-2 .4
. 5
-2 .2
. 3
-2 . 0
.2
-1 . 8
. 1
-1 . 7
. 0
-1 . 6
- . 1
-1 . 5
- .2
-1.4
- .2
-1 . 3
- . 3
-1.2
- . 3
-1 .1
- .4
-1 . 0
- .4
-1 . 0
- . 5
- . 9
- . 5
- . 9
- . 6
- . 8
- . 6
- . 8
- . 6
- . 7
- . 7
- . 7
- . 7
- . 7
- . 7
- . 6
- . 8
- . 6
- . 8
- . 6
- . 8
- . 6
- . 9
- . 5
- . 9
- . 5
- . 9
- . 5
- . 9
- . 5
- . 9
- . 5
1 . 0
- .4
1 . 0
- .4
1 . 0
- .4
1 . 0
- .4
1 . 0
- .4
1 .1
- .4
1 .1
- .4
1 .1
- .4
1 .1
- . 3
1 .1
- . 3
1 .1
- . 3
1 .1
- . 3
1 .1
- . 3
END OF CORJET PREDICTION: Total number of integration steps = 475
JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ
Note: CORJET has been used outside the CORMIX system, assuming unlimited
receiving water. Carefully examine all results for possible boundary
effects due to surface, bottom, or lateral boundaries I
144
-------
The CORJET program when called within
the normal CORMIX installation after its execution
automatically links to the graphics package
CMXGRAPH so the user can inspect the
predicted plume, rather than looking at the output
file. Many graphics options (see Section 5.3)
exist to fully evaluate the plume geometry and
concentration distributions. Three examples of
graphics output are shown in Figures E.2 and E.3.
Figure E.2 shows the plan view, side view,
and side view along the trajectory, respectively, of
the plume, all with a plot scale fixed to 1:1, i.e.
undistorted. All these figures have been
produced with the Postscript-file print option (I) of
CMXGRAPH (in contrast to all the figures in
Appendices B to D that were made with the
screen print (C) option). Such an undistorted is
always preferable for the viewer of such plots in
order to get an unbiased picture of the mixing
pattern. Note the merging of the individual jets in
the plan view. Figure E.3 gives the concentration
distribution along the plume centerline trajectory,
showing the rapid drop-off in this jet mixing
process.
E.2 Smoke plume in stratified atmosphere
with skewed wind velocity
As mentioned in Section 6.1 CORJET is
also applicable for atmospheric conditions in
which case the concept of potential density based
on the perfect gas equation with adiabatic
conditions is employed. Furthermore, the wind
conditions in the lower atmospheric boundary
layer with its greater freedom laterally often has a
skewed velocity distribution with different wind
directions at different levels above the ground.
This is the topic of this case study.
An industrial chimney with a height of 40
m above ground discharges hot gases at a
temperature of 200 °C into the atmosphere. The
discharge has a diameter of 3 m and an exit
velocity of 10 m/s. A discharge concentration of
100 % exists for a fairly rapidly decaying
substance with a decay rate of 1 per 10 min or
0.0028 /s.
Typical measurements, for example using
a tracked rising balloon, give the distribution of
temperature and wind velocity as a function of
height above the ground. This is shown in the
CORJET data preparation checklist given as
Figure E.4. Density data is specified in this case
as air temperature, the program will convert
density inputs internally to potential density as a
function of temperature. The wind velocity vector
with increasing height deviates increasingly from
the direction at ground level. In this example the
coordinate system has been set at ground level
so that the chimney (i.e."port") height is equal to
40 m.
Table E.3 shows the input data file for this
case, while Table E.4 is the CORJET prediction
file. The file echoes the input data, but also lists
the potential density values, and all important
parameters and non-dimensional numbers.
Predicted plume properties are shown
graphically as Figures E.5 and E.6. Figure E.5
shows the plan view and the side view,
respectively, of the plume, both with a plot scale
fixed to 1:1, i.e. undistorted. The plan view shows
that the plume follows the variable direction of the
wind as it rises to higher levels.
Figure E.6 gives the concentration
distribution along the plume centerline trajectory.
The added effect of plume decay would be
discernible only in the detailed output file (Table
E.4) where the centerline concentration is not
merely the inverse of the hydrodynamic centerline
dilution (the effect of pure mixing) but lower
because of the internal chemical decay effect.
145
-------
CORJET Prediction File: postcjcase5mpd.OUT
Case5: MULTIPORT DIFFUSER: STRATIFIED, VARIABLE CU
Plot Oistonion • Y.000
(a)
CORJET Prediction File: postcjcase5mpd.OUT
Case5: MULTIPORT DIFFUSER: STRATIFIED, VARIABLE CU
Plot Distortion » 1.000
(b)
CORJET Prediction
Case5: MULTIPORT DIFFUSER: STRATIFIED, VARIABLE CU
File: postcjcase5mpd.OUT
Side View Along Plan Trajectory
Ptot Distortion » 1.000
Plan Oist (m)
(c)
Figure E.2: CORJET prediction for multiport diffuser discharge into stratified coastal waters as plotted
with graphics package, a) Plan view, b) side view, and c) side view along trajectory both with plot scale
fixed at 1:1 (undistorted).
146
-------
CORJET Prediction
Case5: MULTIPORT DIFFUSER: STRATIFIED, VARIABLE CU
File: postcjcase5mpd.OUT
—r-
25
50 75
Concentration vs Centerline Distance
—r
12S
Oist (m)
Figure E.3: CORJET prediction for multiport diffuser discharge into stratified coastal waters as plotted
with graphics package. Concentration along centerline trajectory.
147
-------
CHECKLIST FOR DATA PREPARATION
CORJET - CORNELL BUOYANT JET INTEGRAL MODEL-- Version 4.1
DOS File Name: CASE3AIR.INP Date: ?^2/96
Prepared by:
Label: Case 3: CHIMNEY, STRATIFIED AIR, VARIABLE WIND
Fluid/Density:
Fluid: JfctfwnteOc Density specification: 1 (via temp.fegfc) Number of ambient levels: 4
2 (air) (1 to 10)
Ambient Da
Level No.
ta:
Elevation
(m)
Temperature
CO
Salinity
(PPt)
Density
(kg/m3)
Velocity
(m/s)
Angle of
velocity (deg)
1
0
12.0
-
-
2.0
0
2
50
12.0
_
_
5.0
15
3
100
12.5
-
-
6.0
25
4
200
13.0
6.5
30
Discharge Conditions:
Number of openings:
(=1 for single port s.p.)
1
Port
diameter (m)
3.0
Height above
origin (m)
40.0
Exit velocity
(m/s)
10.0
Vertical
angle (deg)
90.0
Horizontal
angle (deg)
0.0
Discharge
conc. (any
units)
100
Coefficient of
decay (Is)
0.0028
Discharge
temp. (°C)
200.
Discharge
salinity (ppt)
Discharge
density
(kg/m3)
Diffuser
length (m)
(= 0. if s.p.)
0.0
Alignment
angle (deg)
(= 0. if s.p.)
0.0
Program Control:
Max. vertical Min. vertical Max. distance along Print intervals: jq
distance (m): 200 distance (m): 0 trajectory (m): 1000 (best 5 to 10)
Figure E.4: Data preparation checklist for CORJET simulation of chimney discharge into
stratified atmosphere with skewed wind velocity distribution
148
-------
Table E.3
CORJET input data file for chimney discharge into stratified atmosphere
with skewed wind
#CORJET INPUT FILE
#Title line (50 characters max.):
Case3: CHIMNEY, STRATIFIED AIR, VARIABLE WIND
#Fluid (l=water,2=air), Density option (l=calculate,2=specify directly):
#Fluid (1/2) : Density option (1/2) : Ambient levels (1-10) :
2 1 4
#Ambient conditions (if d.o.=l, fill in TA+SA; if 2, fill in RHOA):
#Level
ZA
TA
SA RHOA
UA
TAUA
1
0 .
12 . 0
2 . 0
0 .
2
50 .
12 . 0
5 . 0
15 .
3
100 .
12 . 5
6 . 0
25
4
200 .
13 . 0
6 . 5
30 .
#Discharge conditions (T0+S0, or RHOO as above; if NOPEN=l: set LD=0,ALIGN=0):
#NOPEN DO HO U0 THETAO SIGMAO CO KD TO SO RHOO LD ALIGN
1 3.0 40. 10.0 90. 0. 100. .0028 200. 0. 0.
#Program control:
#ZMAX ZMIN DISMAX NPRINT
Table E.4
CORJET prediction file for chimney discharge into stratified atmosphere
with skewed wind
CORJET PREDICTION FILE:
JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ
CORJET: CORNELL BUOYANT JET INTEGRAL MODEL Version 4.1, April 1996
FILE NAME:
Label/identifier:
Time of CORJET run:
post\cj\case3air.OUT
Case3: CHIMNEY, STRATIFIED AIR, VARIABLE WIND
4/13/96--16:12:15
Density option: 1
Ambient
conditions: No. of
levels: 4
Fluid:
: Air
LEV
ZA TA SA
RHOA
UA
TAUA
1
.00 12 .00 .00
1 .24
2 .00
.00
2
50 .00 12 .00 .00
1 .24
5 .00
15 .00
3
100.00 12.50 .00
1 .24
6 .00
25 .00
4
200 .00 13 .00 .00
1.23
6 .50
o
o
o
ro
Discharge conditions (metric): SINGLE PORT
DO HO U0 THETAO SIGMAO CO KD TO SO RHOO
3.000 40.00 10.00 90.00 .00 .10E+03 .28E-0 200.0 .0 .75
Program control:
ZMAX ZMIN DISMAX NPRINT
200 .00 .00 1000.00 30
Flux variables (based on ambient at discharge level):
Q0
QT0
. 707E+02
. 133E+05
M0
QS0
. 707E+03
. 000E+00
JO
. 275E+03 GP0
. 390E+01
Length scales (m) and parameters:
LQ = 2.6 6 LM
Lmp = 11.97 Lbp
FRO = 2.92 R
Zone of flow establishment
LE = .00 XE
THETAE= 41.69 SIGMAE=
8 .26
14 .42
(m)
12
.00
.00
Lm
YE
GAMMAE=
6.04 Lb
.00
41 .69
ZE
3 .23
40 .00
CORJET PREDICTION:
Single jet/plume:
Stepsize =
.6042 Printout every 30 steps
X
Y
Z
Sc
Cc
B |
DIST
Save
Gpc dTc
dSALc
.00
.00
40 .00
1 . 0
. 100E+03
1 . 50 |
.00
1. 0
. 39E+01188.0
. 0
.00
.00
40 .00
1 . 0
. 100E+03
1 . 50 |
.00
1.4
.41E+ 012 04 .4
. 0
15 .18
3 .42
49.21
4 . 5
. 221E+02
3 . 53 |
18 .13
6 . 6
.12E+01 41.6
. 0
31 .38
7 54
56 .20
9 . 6
. 104E+02
5 .18 |
36 .25
13 . 8
.6 3E+ 0 0 19.5
. 0
47 .86
12 .09
62 .22
15 . 8
. 634E+01
6 . 64 |
54 .38
22 . 5
.3 9E+ 0 0 11.8
. 0
64 .47
16 97
67 .60
22 . 7
. 44 0E+ 01
7 . 96
72 . 51
32 .2
. 2 7E+ 0 0 8.1
. 0
149
-------
81.13 22.13 72.
97.83 27.54 77.
114.52 33.18 81.
131.21 39.03 85.
147.88 45.08 89.
164.52 51.31 92.
181.14 57.72 96.
197.71 64.29 99.
214.26 71.02 102.
230.77 77.88 105.
247.25 84.85 108.
263.71 91.92 111
280.14 99.07 113
296.56 106.30 116
312.96 113.58 118
329.34 120.93 121
345.70 128.34 123
362.05 135.79 126
378.39 143.29 128
394.72 150.83 130
411.03 158.41 133
427.33 166.03 135
443.62 173.69 137
459.90 181.39 139
476.17 189.11 141
492.43 196.87 143
508.68 204.66 145
524.92 212.48 147
541.15 220.33 149
557.37 228.20 151
573.58 236.11 153
589.79 244.03 154
605.98 251.98 156
622.17 259.96 158
638.36 267.96 159
654.53 275.98 161
670 .69 284 . 03 163
686 .85 292 .09 164
703.01 300.18 166
719.15 308.28 167
735.29 316.41 169
751.42 324.56 170
767.54 332.72 172
783.66 340.90 173
799.77 349.10 174
815.88 357.32 176
831.98 365.55 177
848.07 373.80 178
864.16 382.07 179
880.24 390.35 180
896.32 398.65 182
897.39 399.20 182
Terminal level in
51
06
30
29
05
63
03
27
30.3
38.4
47.0
55 . 9
65.1
74 . 5
84 .2
94 . 0
38 103 . 9
37 113.8
25 123.7
04 133.8
75 143.9
39 154.1
96 164.4
47 174.7
91 185.1
30 195.6
64 206 .1
92 216.6
16 227.2
35 237.8
49 248.4
58 259.0
64 269.6
65 280.3
62 290.9
54 301.4
43 312.0
28 322.5
10 333 . 0
87 343.5
61 353.8
31 364.2
98 374.4
61 384.6
21 394.8
77 404 . 8
30 414.8
79 424.6
25 434.4
68 444.1
08 453.6
44 463.1
77 472.5
07 481.7
34 490.8
57 499.8
78 508.6
95 517.4
09 525.9
17 526.5
stratified
330E+01
260E+01
213E+01
179E+01
154E+01
134E+01
119E+01
106E+01
963E+00
879E+00
808E+00
747E+00
695E+00
649E+00
608E+00
572E+00
540E+00
511E+00
485E+00
462E+00
440E+00
421E+00
403E+00
386E+00
371E+00
357E+00
344E+00
332E+00
321E+00
310E+00
300E+00
291E+00
283E+00
275E+00
267E+00
260E+00
253E+00
247E+00
241E+00
235E+00
230E+00
225E+00
220E+00
216E+00
212E+00
208E+00
204E+00
200E+00
197E+00
193E+00
190E+00
190E+00
ambient
9 .18 |
90 .64
42 . 8
. 2 0E+ 0 0
6 . 0
0
10 . 30|
108.76
54 . 0
. 16E+00
4 . 7
0
11 . 36|
126 .89
65 . 8
. 13E+00
3 . 8
0
12 . 35|
145 . 02
78 .1
. 11E+00
3 .1
0
13 .29|
163.15
90 . 7
. 90E-01
2 . 6
0
14 .18 |
181 .27
103 . 7
.77E-01
2 . 3
0
15 . 02 |
199.40
116 . 9
. 67E-01
2 . 0
0
15 . 83|
217.53
130 .4
.58E-01
1 . 7
0
16 . 60 |
235.66
144 .1
. 52E-01
1 . 5
0
17 . 35|
253.78
157 . 8
. 47E-01
1.4
0
18 . 06 |
271.91
171 . 7
. 42E-01
1.2
0
18.75|
290.04
185 . 6
.3 9E-01
1 .1
0
19 .42 |
308 .17
199 . 6
. 35E-01
1 . 0
0
20 . 07|
326 .29
213 . 7
. 32E-01
. 9
0
20 . 71|
344 .42
228 . 0
.30E-01
. 9
0
21.33|
362 . 55
242 . 3
. 27E-01
. 8
0
21.93|
380 .67
256 . 7
. 25E-01
. 7
0
22 . 52 |
398.80
271 .1
. 23E-01
. 7
0
23 .10 |
416.93
285 . 7
. 22E-01
. 6
0
23 . 66 |
435.06
300 .2
.20E-01
. 6
0
24 .21|
453.18
314 . 8
. 19E-01
. 5
0
24 . 75|
471.31
329 . 5
.17E-01
. 5
0
25 .28|
489.44
344 .1
. 16E-01
. 5
0
25 . 80|
507 . 57
358 . 8
.15E-01
.4
0
26 . 31|
525 .69
373 . 5
. 14E-01
.4
0
26 . 80|
543 . 82
388 .1
.13E-01
.4
0
27.29|
561 . 95
402 . 7
. 12E-01
. 3
0
27.76|
580 . 08
417 . 3
. 11E-01
. 3
0
28 .23|
598.20
431 . 9
.10E-01
. 3
0
28 . 68|
616 .33
446 .4
. 95E-02
. 3
0
29.13|
634 .46
460 . 9
. 88E-02
. 3
0
29 . 57
652 .59
475 .2
. 81E-02
.2
0
o
o
o
ro
670 . 71
489 . 6
. 74E-02
.2
0
30 .42 1
688 . 84
503 . 8
. 68E-02
.2
0
ro
CO
o
ro
706.97
517 . 9
. 63E-02
.2
0
31.23|
725 .09
532 . 0
. 57E-02
.2
0
31 . 62 |
743 .22
545 . 9
. 52E-02
.2
0
32 . 01|
761 .35
559 . 7
. 47E-02
. 1
0
32 . 39|
779.48
573 .4
. 42E-02
. 1
0
32 . 76 |
797.60
587 . 0
. 38E-02
. 1
0
33.12 |
815.73
600 .4
. 34E-02
. 1
0
33 .47|
833 .86
613 . 8
.3 0E-02
. 1
0
33 . 82 |
851 . 99
626 . 9
. 26E-02
. 1
0
34 .16 |
870.11
639 . 9
. 22E-02
. 1
0
34.49|
888 .24
652 . 8
. 18E-02
. 1
0
34 . 81|
906 .37
665 . 5
. 15E-02
. 0
0
35 .13|
924.50
678 . 0
. 12E-02
. 0
0
35 .43|
942 . 62
690 . 3
. 87E-03
. 0
0
35 . 73|
960 . 75
702 . 5
. 57E-03
. 0
0
36 . 03 |
978 .88
714 . 5
.2 9E-0 3
. 0
0
36 . 31|
997 . 01
726 .2
. 15E-04
. 0
0
36.33
998 .21
727 . 0
- . 19E-05
. 0
0
has been reached.
PROGRAM STOPS
END OF CORJET PREDICTION: Total number of integration steps = 1653
JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ
150
-------
(a)
CORJET Prediction
Case3: CHIMNEY, STRATIFIED AIR, VARIABLE WIND
File: postcjcase3air.OUT
Plan View
Plot Distortion ¦ t.000
CORJET Prediction File: postcjcase3air.OUT
Case3: CHIMNEY, STRATIFIED AIR, VARIABLE WIND
Figure E.5: CORJET prediction for chimney discharge into stratified atmosphere with skewed wind
profile as plotted with graphics package, a) Plan view, and b) side view along trajectory both with plot
scale fixed at 1:1 (undistorted).
151
-------
CORJET Prediction
Case3: CHIMNEY, STRATIFIED AIR, VARIABLE WIND
File: postcjcase3air.OUT
!-
iii.. —i—i—i—i—i—i—i—'—i—i—
ISO 300 450 600
Concentration vs Downstream Distance X
750
X (m) -
Figure E.6: CORJET prediction for chimney discharge into stratified atmosphere with skewed wind
profile as plotted with graphics package. Concentration along centerline trajectory.
152
------- |