United States National Exposure EPA/600/R-03/025
Environmental Protection Research Laboratory March 2003
Agency Research Triangle Park NC 27709
Dilution Models for Effluent Discharges
4th Edition
(Visual Plumes)
by
W.E. Frick1, P.J.W. Roberts2, L.R. Davis3,
J. Keyes4, D.J. Baumgartner5, K.P. George6
1 Ecosystems Research Div., NERL, USEPA, Athens, Georgia 30605-2700
2 Georgia Institute of Technology, Atlanta, Georgia 30332
3 CH2M HILL, Corvallis, Oregon 97330
4 Brown and Caldwell, Atlanta, Georgia 30346
5 University of Arizona, Tucson, Arizona 98706
6 Alaska Department of Environmental Conservation, Juneau, Alaska 99801
4 March 2003
Ecosystems Research Division, NERL, ORD
U.S. Environmental Protection Agency
960 College Station Road
Athens, Georgia 30605-2700
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Abstract
Visual Plumes (VP), is a Windows-based computer application that supersedes the DOS
PLUMES (Baumgartner, Frick, and Roberts, 1994) mixing zone modeling system. VP simulates
single and merging submerged plumes in arbitrarily stratified ambient flow and buoyant surface
discharges. Among its new features are graphics, time-series input files, user specified units, a
conservative tidal background-pollutant build-up capability, a sensitivity analysis capability, and
a multi-stressor pathogen decay model that predicts coliform mortality based on temperature,
salinity, solar insolation, and water column light absorption..
VP addresses the issue of model consistency in a unique way, by including other models in
its suite of models. In this way it promotes the idea that in the future modeling consistency will be
achieved by recommending particular models in selected flow categories. This approach is intended
to encourage the continued improvement of plume models. Consistent with this goal, VP includes
the DKHW model that is based on UDKHDEN (Muellenhoff et al., 1985), the surface discharge
model PDS (Davis, 1999), the three-dimensional UM3 model based on UM, and the NRFIELD
model based on RSB. These models may be run consecutively and compared graphically to help
verify their performance. The Brooks equations are retained to simulate far-field behavior. Finally,
DOS PLUMES may be selected as one of the "models," giving full access to its capabilities.
The time-series file-linking capability provides a way to simulate outfall performance over
long periods of time. Most effluent and ambient variables can be input from files that store data that
change with time. This is the heart of the pollutant-buildup capability, designed for one-dimensional
tidal rivers or estuaries to estimate background pollution from the source in question. It is also the
basis for utilizing the Progressive Vector Diagram (PVD) approach. The time-series file linking
capability is served by "summary" graphics, i.e., graphics that focus on overall performance
indicators, like mixing zone dilutions or concentrations. These implementations allow plumes to be
depicted in the far-field as individual plumes (for one or two runs) or as concentration "clouds" for
many runs. This capability is useful for estimating beach impacts in situations exhibiting simply
bathymetries.
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Disclaimer
This document has been reviewed in accordance with the US Environmental Protection Agency's
peer and administrative review policies and approved for publication. Mention of trade names or
commercial products does not constitute endorsement or recommendation for use by the US EPA.
VI
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Table of Contents
Frontispiece iii
Abstract v
Disclaimer vi
Table of Contents vii
Acknowledgments xi
1 Introduction 1.1
1.1 General Overview of the Interface 1.2
1.2 Models Supported by the Visual Plumes Platform 1.3
2 General Introduction to Visual Plumes (VP) 2.1
2.1 Menus 2.1
2.2 Tabs 2.3
2.2.1 Diffuser tab 2.4
2.2.2 Ambient tab 2.8
2.2.3 Special Settings tab 2.11
2.2.4 Text Output tab 2.15
2.2.5 Graphical Output tab 2.16
2.3 Model-specific panels and components 2.20
3 Entering Data 3.1
3.1 Diffuser Tab 3.1
3.1.1 Diffuser table variables 3.2
3.2 Ambient Tab 3.3
3.2.1 Ambient table variables 3.3
3.2.2 Creating Ambient tables 3.4
3.3 Database Files 3.5
3.4 Files and Filename Conventions 3.5
4 Introductory Tutorial 4.1
4.1 Important mixing zone modeling terms and concepts 4.1
4.1.1 Properties that affect entrainment 4.4
4.1.2 Properties that affect effective dilution 4.5
4.1.3 The dilution and ambient tables as property repositories 4.6
4.2 The One-port example 4.6
4.2.1 Starting and exploring VP 4.7
4.2.2 Problem description 4.10
4.2.3 Inputting the data 4.11
vii
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4.2.4 Modifying the project 4.14
4.2.5 Adding another ambient scenario 4.19
4.3 Multi-port discharge 4.24
5 Advanced Considerations 5.1
5.1 Time Related Data, Time-Series Files 5.1
5.2 Depth vs. Height 5.4
6 Additional Applications 5.1
6.1 Oil well problem 6.1
6.2 The Tidal Pollution Background Buildup Capability 6.10
6.3 Advanced application: time-series files 6.12
6.3.1 Conservative pollutant 6.12
6.3.2 A pathogen 6.20
6.4 Application of the surface discharge model, PDS 6.25
6.4.1 General comments regarding the PDS (PDSwin.exe) model 6.25
6.4.2 Sample PDS problem 6.25
6.5 Ocean outfall problem 6.29
6.5.1 The Mancini bacteria decay model 6.34
6.5.2 Assumptions, the user's domain 6.35
7 Model Theory 7.1
7.1 Visual Plumes 7.1
7.1.1 Bacteria models 7.1
7.1.2 Tidal buildup capability 7.1
7.1.3 Nascent density 7.1
7.2 UM3 theory 7.4
7.2.1 Established theory 7.4
7.2.2 Three-dimensional generalization 7.5
8 Model Availability and Performance 8.1
8.1 Model verification and comparison 8.1
8.2 Troubleshooting 8.1
8.2.1 Problems and solutions 8.1
8.2.3 Hints 8.4
8.2.3 Known or suspected bugs 8.5
9 Extended Bibliography 9.1
9.1 Selected references 9.1
9.2 Extended bibliography 9.2
Appendix: Notes and important recent changes A. 1
Index
Vlll
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IX
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Acknowledgments
Many individuals have contributed to the conception, development, debugging, review,
modification, and encouragement of this work. We would like to gratefully acknowledge some of
them:
Rosemarie Russo Harvey Holm Gabrielle Puz
Craig Barber Hening Huang Diana Robles
Jon Bergengren Carlos Irizarry Lew Rossman
Sandy Bird Sam Karickhoff Tim Rowan
Hira Biswas Russell Kinerson Henry Salas
Maynard Brandsma Bob Languell Robson Sarmento
Dave Brown Astrid Larsen Jenny Scifres
Tom Cavinder Joseph Lee Anne Sigleo
Wen-Li Chiang Winston Lung Mills Soldate
Curtis Dal ton Brandy Manders Frank Stancil
Debra Denton Steve McCutcheon Robyn Stuber
Joseph DiLorenzo Frank Meriwether Patricia Tapp
Bill Driskell Susanne Metzgar Bruce Titus
Larry Fradkin Bill Mills Gil Veith
Norm Glenn Phil Mineart Jim Weaver
David Hericks Bruce Nairn John Yearsley
Mike Heyl Terry Oda David Young
Thomas Hogbom
Part of Windows PLUMES development was conducted under a Cooperative Research And
Development Agreement (CRAD A) between the U. S. Environmental Protection Agency and CH2M
HILL. CH2M HILL's contribution of time, facilities, and funding to help in the development of WP
is greatly appreciated. We also appreciate the time given by the peer reviewers and many Beta users
and their helpful suggestions.
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XI
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1 Introduction
Visual Plumes is a Windows-based mixing zone modeling application designed to replace
the DOS-based PLUMES program (Baumgartner, Frick, and Roberts, 1994). Like PLUMES, VP
supports initial dilution models that simulate single and merging submerged plumes in arbitrarily
stratified ambient flow. Predictions include dilution, rise, diameter, and other plume variables. The
Brooks algorithm is retained for predicting far-field centerline dilution and waste field width. New
features include the surface discharge model (PDS), the multi-stressor bacterial decay model (based
onMancini, 1978), graphics output, time-series input, a sensitivity analysis capability, user-specified
units, and a conservative tidal background pollutant build-up capability.
VP differs greatly from PLUMES in terms of operating system, model enhancements, model
additions, organization, and appearance. The single-port Windows version of the UM model is now
a fully three-dimensional flow model. It is renamed UM3 to emphasize this change and to
differentiate it from the previous version. UDKHDEN, also a three-dimensional model, was one of
the models in EPA's earlier guidance (Muellenhoff et al., 1985) that is reintroduced under the name
DKHW. This addition illustrates a commitment to a comprehensive modeling platform that will
foster scientific competition by encouraging modelers to continue to improve their applications.
Some parts of PLUMES have been brought in basically unchanged. The RSB model is one
of these although its new name, NRFIELD and FRFIELD, sets the stage for introducing planned
changes. For the many users of PLUMES who wish to support earlier projects or take advantage
of some of its features, like computing length-scale, similarity parameters, and related input
variables not explicitly supported by VP, VP is backward compatible. DOS PLUMES is one of the
"models" supported VP. When selected, VP prepares the necessary PLUMES input file and displays
the output, interpreting some of it graphically. For porting projects to VP, it also reads PLUMES
input files (files with the VAR extension).
Like DOS PLUMES, VP allows the user to run many cases, however, multiple cases are
easier to set up and to compare. Determining model sensitivity to various input parameters is
facilitated. The ability to run different models, such as UM3 and DKHW, side by side and compare
the results in graphical form, should facilitate model comparison. The ability to link in and graph
verification data from files rounds out the ability to compare models.
Perhaps no other capability sets VP apart from PLUMES more than its ability to link in
time-series files. This capability provides a way to simulate outfall performance over a long period
of time and, thereby, over many environmental scenarios. Most effluent and ambient variables, such
as effluent discharge rate and current direction, can be read from files containing values that change
with time over different time intervals. Thus, a 24-hour diurnal flow file, cycled repeatedly, might
be combined with a current-meter data set thousands of records long. This is the heart of the
pollutant-buildup capability, the ability in one-dimensional tidal rivers or estuaries to estimate
background pollution from the source in question. The time-series file linking capability is served
by "summary" graphics, i.e., graphics panels that focus on overall performance indicators, like
mixing zone dilutions or concentrations. The use of time-series files does imply the preparation of
the necessary data in ASCII form, as described herein.
For all its changes, VP is still a transition product. First, VP only begins to take advantage
of the object-oriented programming paradigm offered by the Delphi language in which it was
1.1
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developed. Ideally, there will be time in the future to fully take advantage of this modeling
paradigm, which would help enhance the interface and solve some of VP's current problems with
maintainability. Second, VP is only a prototype for a comprehensive modeling platform that could
ultimately support diverse mixing zone models, while also including a protocol designed to satisfy
applicable regulations. When specified, the protocol would automatically run the currently
recognized official models. Thus VP would foster scientific competition while supporting modeling
consistency. Third, the tidal pollutant buildup capability is only a step in the direction of a fully
three-dimensional mixing zone analysis package of the future.
1.1 General Overview of the Interface
The VP user interface is organized into five tabs: Diffuser, Ambient, Special Settings, Text
Output, and Graphics. For setup and input, several Windows controls and components, such as
tables, pull-down and pop-up menus, buttons, and lists are provided. Numerical input is dominated
by two input tables, defining the diffuser characteristics and flow conditions and the ambient
conditions. Other information is input in a memo box, a number of control panels, lists, and buttons,
and, various edit boxes, lists, file dialogs, and radio buttons on the Special Settings tab.
A context-sensitive help system allows one to right-click on any component on the screen,
or use the help menu. Many help topics contain hypertext links; text displayed in green may be
clicked to display further information on the indicated item.
To reduce redundancy, several input interpretation techniques have been written into VP to
make input requirements contingent on actual availability of data. In many applications, input tables
must be completely filled in with data, whether the data are redundant or not. In VP, data need not
be entered into the input tables when their existence is not implied. For example, if a measurement
program sampled current speed at 10 and 30 meter depth and temperature at the surface and 25m,
then four rows of input cells are needed to hold the data. However, VP requires the user to enter
current speed only on the 10 and 30m rows, not on the surface and 25m rows. The exception is in
the diffuser table where all required columns must have a value in the first row, which is called the
base case.
To prepare VP to run the user must define the base case and complete at least one ambient
profile in the table on the Ambient tab. Model selection and case specific information determines
which columns require input; columns labeled n/r are not required by the specified configuration
or target model. For more than one run, or rows, only cell values that are different from the base case
need be entered. If a cell is empty, its value is inherited from the previous row. The runtime mode
is determined by the setting of the Case selection radio button panel; choices are individual cases,
all cases in sequence (running all ambient files or parsing the case range appended to the ambient
file name), or all possible combinations of cases.
The organization of the data on different tabs emphasizes that VP diffuser and ambient input
data are maintained in separate files with a db extension. With PLUMES it was often difficult to tell
how individual cases varied from each other. VP alleviates that problem by file separation, which
avoids repetition of ambient data. The advantage of storing the data in separate files is that ambient
data files can be used for other projects.
1.2
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VP supports user-specified units. On both Diffuser and Ambient tabs, the user can click on
the row above the input table to select units from a list of up to five choices revealed on a pop-up
list. Unless the Units conversion radio button is set to label only, the data in the affected columns
are automatically updated to convert to the new unit. In addition, some of the columns are multi-use
columns. For example, the salinity column can be changed to a density column by simply selecting
a density unit from the list of unit options.
The Special Settings tab provides a choice of output variables and access to other controls,
parameters, and options. The Text Ouput and Graphical Output tabs display the output. Graphics
can be customized by double-clicking in the margins of each panel. Other options are provided on
the left side of the graphing panels, including the Verify button that opens a verification file dialog
box. Many VP settings are stored in the project file with the 1st extension.
1.2 Models Supported by the Visual Plumes Platform
There are presently five recommended models in VP: DKHW, NRFIELD/FRFIELD, UM3,
PDSW, and DOS PLUMES. These and the Brooks far-field algorithm and an experimental vector
model are briefly described below.
UM3
UM3 is an acronym for the three-dimensional Updated Merge (UM) model for simulating
single and multi-port submerged discharges. The model is coded in Delphi Pascal, the language of
Visual Plumes.
UM3 is a Lagrangian model that features the projected-area-entrainment (PAE) hypothesis
(Winiarski and Frick, 1976; Frick, 1984). This established hypothesis (Rawn, Bowerman, and
Brooks, 1960) quantifies forced entrainment, the rate at which mass is incorporated into the plume
in the presence of current. In UM3 it is assumed that the plume is in steady state; in the Lagrangian
formulation this implies that successive elements follow the same trajectory (Baumgartner et al.,
1994). The plume envelope remains invariant while elements moving through it change their shape
and position with time. However, ambient and discharge conditions can change as long as they do
so over time scales which are long compared to the time in which a discharged element reaches the
end of the initial dilution phase, usually at maximum rise.
To make UM three-dimensional, the PAE forced entrainment hypothesis has been
generalized to include an entrainment term corresponding to the third-dimension: a cross-current
term. As a result, single-port plumes are simulated as truly three-dimensional entities. Merged
plumes are simulated less rigorously by distributing the cross-current entrainment over all plumes.
Dilution from diffusers oriented parallel to the current is estimated by limiting the effective spacing
to correspond to a cross-diffuser flow angle of 20 degrees.
The runtime and display performance of UM3 has been improved by better controlling the
simulation time step. In addition to being controlled by the amount of entrainment, the time step is
now also sensitive to the amount of trajectory curvature. In some cases, this sensitivity to curvature
actually reduces the number of time steps needed to produce a simulation because the sensitivity to
entrainment can be reduced.
1.3
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Due to the fact that UM3 is coded in Delphi Pascal, the native language of VP, UM3 is fully
integrated with VP's background build-up capability. Given that a time-series record for tidal flow
in a one-dimensional channel can be provided, VP can estimate the buildup of background
concentration resulting from the repeated passage of a given fetch of water past the discharge.
DKHW
DKHW is an acronym for the Davis, Kannberg, Hirst model for Windows. Like UM3,
DKHW is also a three-dimensional plume model that also applies to single and multi-port
submerged discharges. Unlike UM3, DKHW is a Fortran-based executable that is called by VP on
demand. This method of implementation plus a more detailed near-field theory carries a penalty in
the form of generally greater execution time.
Within VP, DKHW runs from a DOS SHELL evidenced by a DOS window that appears
when it is run. Depending on the operating system, one may need to close the DOS window after
DKHW is finished running. The word "finished" appears in the window's title bar to indicate that
DKHW is done, at which time the window may be closed.
DKHW is based on UDKHG and UDKHDEN described in Fundamentals of Environmental
Discharge Modeling (Davis, 1999). It uses the Eulerian integral method to solve the equations of
motion for plume trajectory, size, concentration and temperature. In this approach distance is the
independent variable, whereas in the Lagrangian formulation time is the independent variable.
DKHW provides detailed calculations in both the Zone of Flow Establishment (ZFE) and
in the fully developed zone, and considers gradual merging of neighboring plumes. This ability to
model the near field in great detail is currently receiving renewed interest because salmonids are
very sensitive to elevated temperature.
DKHW is presently limited to positively buoyant plumes.
PDSW
PDSW is the VP name for the PDSWIN executable model, an acronym for the Prych, Davis,
Shirazi model for Windows, which has been modified to be compatible with VP. PDSWIN is a
version of the PDS surface discharge program also described in Fundamentals of Environmental
Discharge Modeling (Davis, 1999). PDS is a three-dimensional plume model that applies to
discharges to water bodies from tributary channels, such as cooling tower discharge canals. Like
DKHW, PDSWIN is a Fortran-based executable that is called by VP on demand.
PDSWIN provides simulations for temperature and dilution over a wide range of discharge
conditions. It was used to develop the nomograms in Shirazi and Davis (1972). PDS is an Eulerian
integral flux model for the surface discharge of buoyant water into a moving ambient body of water
that includes the effects of surface heat transfer. The plume is assumed to remain at the surface with
buoyancy causing it to rise and spread in all directions. The initial discharge momentum causes the
plume to penetrate the ambient at the same time that the current bends the plume in the direction of
flow. Discharge is assumed to be from a rectangular conduit into a large body of water. PDSWIN
calculates plume trajectory, average and centerline dilution, plume width and depth and centerline
excess temperature. It also calculates the areas within selected isotherms. In addition to VP output,
additional output data are available in the PDS.OUT file in the default directory using any
1.4
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compatible text editor. The user must monitor boundaries. Calculations beyond the point where the
plume hits a boundary are questionable. Plume attachment at the near shore can be simulated using
the image method in which the discharge flow and width are doubled and only one half of the
resulting plume is considered. As with DKHW, the DOS window may have to be closed when
PDSWIN is finished.
NRFIELD
NKFIELD (RSB), as its entry on the Model menu suggests, is the successor to the PLUMES
RSB model. NRFIELD is an empirical model for multiport diffusers based on the experimental
studies on multiport diffusers in stratified currents described in Roberts, Snyder, and Baumgartner
(1989, a, b, c) and subsequent experimental works. NRFIELD is based on experiments using
T-risers, each having two ports, so at least four ports must be specified for it to apply. An important
assumption is that the diffuser may be represented by a line source. This assumption may have
important implications on small mixing zones, in which the plumes may not have merged.
FRFIELD
The FRFIELD model estimates the long-term distribution of pollutants in the vicinity of the
outfall. This models is based on the two-dimensional "visitation-frequency" model is not currently
operational.
DOS PLUMES
DOS PLUMES, formerly called PLUMES, is the direct predecessor of VP. The PLUMES
users' guide (Baumgartner, Frick, and Roberts, 1994) is available on the VP compact disk and the
program may run independently of VP. It is linked to VP for two main reasons. First, many
individuals have used PLUMES and have developed project files that they wish to import into VP,
and, second, PLUMES has some unique capabilities that may be useful to the VP user. For example,
the DOS application provides an easy way to develop the numerical identity between related
variables, like between port effluent speed and direction and port effluent vector velocity
components. The ability to process and display PLUMES output also allows one to see how
modeling improvements have changed the predictions.
3-D, single-port vector model
This is an experimental model that is not currently recommended for official use.
Brooks far-field algorithm
This "model" is functionally different from the foregoing models in that it is not listed on
the Models menu. Instead, it is specified by checking the Brooks far-field solution option on the
Model Configuration checklist on the Diffuser tab. Briefly, the algorithm is a simple dispersion
calculation that is a function of travel time and initial waste-field width.
1.5
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Compared to the PLUMES version, the Brooks far-field algorithm has been considerably
improved. In addition to having better control over output variables, the algorithm, through the VP
time-series capability can now simulate time-dependent behavior. Thus, diel and other cycles can
now be simulated. This is very important for estimating the effect of highly variable mechanisms
such as bacterial decay, which depends greatly on the variable intensity of ultra-violet radiation.
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2 General Introduction to Visual Plumes (VP)
VP has been designed to be similar to standard WINDOWS applications featuring menu bars,
dialogue windows, check boxes, tabs, panels, and other components. The more important of these
visual features are briefly described below.
2.1 Menus
Edit Models Stop Fit
Open Project
Add Ambient
Create Project
Save project as
IrnportVAR file
Import UDF (ASCII) file
10pen Old Project
Print
Print Setup...
Exit
File Menu (and file naming conventions)
The File menu (Figure 2.1) allows the user to open an existing
proj ect, add an ambient file to the proj ect, create a new proj ect, save proj ect
files under a new project name, import DOS PLUMES VAR files, import
UDF (ASCII) files, recall a previous project, print the display, setup a
printer, and exit VP. The open, create, and other commands invoke a
standard file directory dialogue window. Ambient files may also be added
to the Ambient file list by right-clicking in the file list window to reveal the
corresponding pop-up menu. The print command prints the graphical image
of the selected tab. For complete text output, an output file may be specified
on the Special Settings tab, or text can be selected and copied from the text
tab and pasted into a text editor.
When a new proj ect i s created, a How to Proceed... window (Figure
2.2) appears to allow the user to specify the intended target model for the
application, and, whether or not to retain graphics from the previous
project. By clicking successively on each model, the table headers can be Figure 2.1 File menu
seen to change in the background. This reflects the requirements of the
different models. Once the Continue button is pressed, VP completes the creation process by giving
the project a unique default name, which the user can change with the Save project as command.
The proj ect file, associated with the Diffuser tab, is given
the extension vpp.db. An example of a default project file
name is VP plume 1.vpp.db, where VP plume 1 is the
default project name.
To complete the proj ect file-creation process, VP
automatically creates two additional files.
The additional file appears on the Ambient tab, its
name consists of the project name followed by ayyy.db
extension, where yyy is a numerical code like 001, 002,
a three-digit number which may be used as a
How to Pioceed.
"Target Model for the New Project
DKHW
NRFIELD
UMfVP)
PDS (sfc)
DOS PLUMES
DKHW
NRFIELD
r PDS (sfc)
(~ DOS PLUMES
etc.
template for additional ambient files identified
different numerical constants (001, 002, etc.)
by
Column 1, clear previous output; Column 2, retain previous output
Continue
Figure 2.2 Specifying a target model
2.1
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The second additional file is an ASCII files that bears the project name followed by the 1st
extension. This file lists proj ect properties for future reference. The list file is read the next time the
project is opened, using it to re-establish most of the settings existing in the previous session. The
file may be edited in any common word processor although this is not recommended. Manual editing
changes must follow the established format or the results may be unpredictable.
Edit Menu
A limited Edit menu allows the user to reset headers and substitute backup files to replace
unwanted changes made since the beginning of the project session. The latter capability is useful
when data corruption is suspected or has occurred.
Models Menu
The Models menu allows the user to select and run the desired model. The models are
described briefly in Section 1.2 above. Notice that at the menu level most models are accessible by
typing the underlined character or hot key. The hot key can be used without clicking the Models
menu. For example, UM3 can be run with a control-U, (AU) keystroke, DKHW with AK, etc.. The
key sequence is not case sensitive. In addition, on both theDiffiiser and Ambient tabs there is a small
blue and yellow icon of a plume. Once a particular model has been selected, a click of the icon runs
the identified model. The Models menu offers a way to change the original target model.
Stop-Run Menu
The Stop Run menu option allows the resident native models, namely UM3 and 3-D, to be
terminated during execution. With VP it is easy to set up numerous runs that can take a long time
to complete. The Stop-Run option will terminate a long chain of runs. The other models run
externally and may be interrupted by closing their windows.
Help Menu
The Help menu provides a fairly traditional help capability, including contents, search, and
about options. Help topics frequently contain green hyperlinks that may be click to cross-reference
related topics.
Speed bar buttons
A speedbar provides menu shortcut buttons for some of the more important menu
commands. As with other components, when the cursor is moved over the buttons, their function
is displayed on the status line at the bottom of the VP window.
2.2
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File Edit Models Stop Run Help
Diffuser: SadogTaseAug 00. vpp.db | Ambient: C:\Plumes\Sadog TaseAugOO.001.db] Special Settings | Textual Output | Giaphical Output | Surface Discharge Model |
Project C:\Plumes\Sadog Tase AugOO
An example potentially involving four flow and discharge
scenarios and two ambient input pies
Ambient file list
Filename Cases
C:\Piumes\Sadoo. Tase Aug 01 ,002.db 1 1
- After run go to tab -
r Diffuser
r Ambient
C Special
T Textual
<* Graphics
: Units Conversion — I
(* Convert data
T Label only
£
Model Configuration
3 Blocks far-field solution
Ll Giaph effective dilution
~i Average piume boundary
D Amb. current vector averaging
a Tidal pollution buildup
barne-levels tiine-ieriei input
(* Base or selected case
r Sequential all ambient list
f* Sequential parse ambient
f All combinations
ser, Flow, Mixing Zone Inputs
nA
Port
elevation
Vertical
angle
Hor
angle
N urn of
ports
Port
spacing
nA
n/r
nA
Acute
mix zone
Chronic
mix zone
Port
depth
Effluent
flow
Effluent
salinity!')
Effluent
temp
Effluent
cone
deg
deg
MSP psu
It
(5
3
0
90
6
3
6
3
19.68
10 100
49 4.8 4.5
30 17000
20
Parameters for selected row
Froude number
Etfdensitu[ka/m31
Port vel Ms]
P-dia (ml
P-dia linl
Case No.
11.64
9390613
1 921
0.1524
6.0
1
Time incit-rrrvr'i In!.
Time cycling.period
es (optional)
snarne
it [hrs'l
jeriod
uniL
Port
depth
SdC^^^H
Borrowtime-series from project: |C:\Plumes\SadogTaseAugOO
Effluent
flow
dick for file
Effluent
salinrM")
Effluent
temp
Effluent
cone ] |
dick for file dick for file dick for file
[Database input table: double click to load ambient file; has a right-click menu
Figure 2.3 The VP interface with the Diffuser tab selected.
2.2 Tabs
Prominent VP features are tabs located below the speed-bar buttons that are stacked over
each other so that only one is visible at a time. They are the Diffuser, Ambient, Special Settings, Text
Output, and Graphical Output tabs. Clicking on any tab places that tab page on top. The Diffuser
and Ambient tabs append the names of the open files to the tab name. Figure 2.3 shows the interface
when the Diffuser tab is clicked. This is the default tab when VP is started.
The tabs' components are generally formatted by color. White background means that the
component can be modified by directly typing, or entering, data and information into the given cells.
A beige background means that the component's contents are manipulated by clicking on it. In some
cases, the beige components have pop-up menus activated by right-clicking on the component. The
contents on the window of each tab are discussed below.
2.3
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2.2.1 Diffuser tab
The Diffuser tab displays the name of the current
project in the yellow box above the Project memo box.
There are several panels on the Diffuser tab that contain
various components. From the top left to the bottom right
these include:
Add file
Add all m
Insert file
Insert all XXH
Remove selected files
Remove selected and following files
Help
Effluent
flow
Effluent
salinity(xj
1. Project memo box: This yellow box displays the
name of the current project. Below it is a memo box
that may be used to define a project by name and to i
write specific notes about the project. This is a ". t , . „, ,.
limited-capability editing window. Scrolling is Figure 2.4 Ambient file list pop-up
supported but space is limited and text after the fifth menu-
blank line is ignored.
2. Ambient file list: This list box displays the name of ambient files
that have been previously created and selected for use with the
project. In addition to the add-ambient command available on the
file menu, a right-click pop-up menu (Figure 2.4) provides
facilities for editing the file list. For more information, see the
description at the end of this subsection.
3. After run go to tab radio group: This group specifies a favorite tab
to move to after a model has been run.
4. Units conversion radio group: Occasionally one may wish to
change the units label without also converting the values in the
column. This option allows the units conversion pop-up menus
(Figure 2.5) to be used to change only the unit label. _,. „ _ TT .
c ,,°, , ~ .. u i r 4. TU- • u i r 4. r u • Figure 2.5 Units
5. Model configuration checklist: This is a checklist for changing &
r. , . 11 ., • , • , , , 4 4 conversion pop-up
fundamentally the way input is read, models are set up to run, f f f
output is presented, and other options. For example, if Average menu
plume boundary is checked, VP graphs an internal boundary at which the plume dilution
equals the average plume-element dilution.
6. Case selection radio button group: This group of push
buttons allows the user to set the run mode. For example,
individual or multiple cases can be selected for
subsequent execution.
7. Diffuser, Flow, Mixing Zone Inputs panel: The heart of
this panel is the diffuser table that provides space for
inputting diffuser specifications and flow conditions.
Cells are provided for inputting data. A right-click on the
48
m3/s I
ui n
MLU
MGD
K3/s
bbl/d
Delete preceding lines
Delete this and following lines
Font pjtch
Help
Cancel
diffuser table reveals the pop-up menu shown in Figure Figure 2.6 Diffuser table pop-up
2.6, which provides additional facilities for editing the menu.
table.
2.4
-------
8. Unit conversion pop-up menus: These pop-up menus allow one to change the units or labels
associated with the cell. A click on the unit label reveals the pop-up menus. An example of
a menu is given in Figure 2.5.
9. Parameters for selected row panel: The button by that name, when clicked, displays
additional information about a specified selected case. The selected case is identified by the
*• character in the left hand margin of the diffuser table. The case is changed by simply
clicking on the row.
10. Finally, the optional Time series files panel and table provides linkage information and
values which, when time-series files have been prepared, is linked by clicking on the top
cells in the grid. This grid is accompanied by & Borrow time-series from project edit box
which allows other projects to be specified from which to input time-series data.
The diffuser input table
This is the large input table in the middle of the tab designed to display diffuser and effluent
flow data. A convenient property of the table is the way it corresponds to desired information.
Except for the first row, or base case, data need only be entered when a particular diffuser or flow
characteristic is to be changed for that row, or case. Blank cells either indicate that the column is not
required (labeled n/r) or the value is the same as the one in the previous row. This implies that all
required columns in the first row, or base case, must be specified.
These general rules are modified to accommodate time-series file data, explained in more
detail in Section 5.
Multiple Ambient Files
Ambient files associated with a proj ect are shown in the Ambient file lists, one on the diffuser
tab and the other on the ambient tab. Both lists can be clicked to change the ambient file displayed
on the ambient file tab and table. However, the master list is on the diffuser tab; only it can be
manipulated to add, insert, or remove files from the list.
Additional ambient files can be added to the master list by right clicking on the list and
selecting theAdd-Jile option from the pop-up menu (see Figure 2.4) and selecting the name of the
desired file from the dialogue window. Again, to display a particular ambient file, or table, simply
click on a particular ambient file name on the list and the identified file is put on the Diffuser and
Ambient tabs. At the same time, the file name appears in the edit box below the list where it can be
edited.
The purpose of the edit box is to make it possible to append case numbers that specify the
range of cases to which the ambient file is to apply. For example, if there are five different cases and
two ambient tables named ambient_file.OO 1 .db and ambient_file.002.db, and one wishes the first file
to be used for Cases 1 through 4 and the second for Case 5, the ambient table names can be modified
in the edit box to show ambient_file.001 .db 1 4, and ambient_file.002.db 5 5. The numbers must be
in ascending order.
After the ambient list has been edited to include the case ranges, there is another way to place
the corresponding files on the Diffuser and Ambient tabs. To see which ambient file is associated
2.5
-------
with a specific row or case in the table, double click on a row and the corresponding ambient file
is shown on the Diffuser and Ambient tabs.
Case selection
In the Case selection box, the Base or selected case option refers to running a specific case,
or row, of diffuser data. A click on a cell in the diffuser table moves the triangular arrow (») to the
left of the table to the specified row and gives that case has focus. If it is the first row, then the base
case has focus. When the required columns are filled in, at least in the first row, a model consistent
with the required columns is ready to be run. (The exception to cells requiring input is when one or
more of the flow variables is linked to a time-series file, in that case the column should be blank
because the variable is read from a file at run time; this is discussed further in Section 5.) Lines
below the base case (first row) need only contain values that are different from the base case.
When one of the Case selection sequential buttons is selected, VP runs the input table from
the top to the bottom of the diffuser table, either systematically running through the ambient-file list
or parsing the row numbers appended to the filenames in the list. If parsing is specified but no
numbers are appended to the file names, VP runs all cases with only the file specified. When the All
combinations option is selected, VP mixes variables in all possible combinations and runs them
creating a complete matrix of input conditions. This includes all ambient tables associated with the
project. (Note: the All combinations option may result in a very large number of runs, the number
depending upon the number of cases, or rows, specified and the number of variables, or columns,
containing more than one value).
Units conversion
The Units conversion radio group options sets one of two modes. In the default Convert data
mode VP will automatically convert a column of values from one set of units to another whenever
a units pop-up menu (Figure 2.5) is used to change units. For example, a temperature of 32 F
becomes 0 C if the initial unit was degrees Fahrenheit and its value was 32 and the Celsius unit is
selected from the pop-up menu. The column unit header is changed accordingly. Try this.
In the Label only mode, only the label is changed. This is convenient when one inadvertently
entered data with a set of units in mind that differ from the indicated set of units. This capability is
also useful when information on units is lost after a power outage. However, usually VP is able to
correctly reestablish the units after a crash as it stores information on units not only in the diffuser
and ambient <$> files but also in the project list file. Sometimes, depending on the situation, restoring
the backup files may be the best way to reestablish a pre-existing file configuration.
Model configuration
The Model configuration checklist has several check boxes for configuring VP. A check
indicates that the option is operational. The checklist is used to fundamentally change the way VP
and the models, particularly UM3, perform at run time. For example, if $\Q Brooks far field solution
selection is checked, VP will add the far-field algorithm solution to the initial dilution prediction.
2.6
-------
Only on the diln (dilution) graphic panel, the Graph effective dilution selection will substitute
an alternative dilution measure, the ratio of the effluent concentration to the plume concentration.
for the mass (or, approximately, the volume) dilution. The effective dilution differs from the mass
dilution when the ambient receiving water contains quantities of the pollutant in question, i.e.,
background pollution. The entrainment of polluted ambient fluid reduces the apparent dilution
because the ambient entrained fluid effectively adds to the plume's pollutant burden.
The Average plume boundary selection graphs an internal plume boundary corresponding
to the average dilution. The value of this capability is that the concentration at this boundary
corresponds to the average dilution output by UM3 and DKHW, both of which adopt the 3/2 power
profile to describe the profile of concentration across the plume cross-section. This is helpful for
determining mixing zone boundary concentrations where its specification is critical. For example,
if the plume approaches the mixing zone boundary at an angle, the criterion concentration may not
be exceeded until this internal boundary crosses the mixing zone.
The Amb current vector averaging selection specifies how the ambient table, specifically,
the current variables, are interpreted. When checked, interpolation at a given depth is based on
vector averaging, otherwise, directions are averaged. For example, suppose the plume element is
halfway between two depths at which the corresponding directions are northward (0 deg) and
southward (180 deg) and at which the current speed has equal magnitudes. Vector averaging will
result in a zero current while angular averaging will result in a current directed in the eastward
direction. In an estuarine or riverine settings, vector averaging is recommended.
UM3 only: the Tidal pollution buildup selection invokes VP's pollution buildup capability.
This capability is intended to be used in estuarine discharge situations where the effect of tides is
to cause the receiving water to pass repeatedly over the discharge point. When checked, every time
a parcel of receiving water passes over the discharge point, effluent is added to it. If the freshwater
flow is small, this process can lead to the repeated loading of a particular parcel of receiving water,
before it finally passes downstream permanently, out of the influence of the discharge. Combined
with the Amb current vector averaging selection, it allows UM3 to estimate (in a conservative
fashion) the background concentration of the receiving water, assuming that the source is
responsible for the presence of pollution in the receiving water.
Useful parameters and conversions
At the lower left corner of the diffuser table is the Parameters for selected row panel that
gives the densimetric Froude number and other project parameters. In addition to the densimetric
Froude number, the effluent density, and the port discharge velocity, it gives the value for the
2.7
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selected cell, one in the primary unit (like meters) and the other in the selected unit (like feet). The
last value is the case number for the specified row. The top three are only updated when the button
is pressed. The value of this panel is limited by the need to update variables which can only be done
by going from column to column, not from row to row. For more information, see Section 4.1 and
Section 6.1.
Time-series input
Near the bottom right of the Diffuser tab is the Time Series File (optional) panel. When there
is no time-series data, or it is not an issue, this panel can be ignored. For time-series analysis,
however, this is the panel where the appropriate time-series files are linked to VP. These files must
have been previously created and have the correct file name. The creation of these files is discussed
in Section 5. Files other than those named using the default names can be specified by using the
Borrow time series from project dialog box.
For example, assuming that the time-series data on effluent flow has been stored in a file
with the correct file name, a click on the click for file cell causes the corresponding file to be linked
to VP. This action causes the words click for file to be replaced by the file name, followed by time
increment, cycle period, and measurement units in the cells below it. These values are read from the
first line of the time-series file. Any value that was in the effluent flow cell of the diffuser table is
replaced by a blank. The reason for this is that VP is set to take flow data from the time-series file
and not from the diffuser table, which represents steady state input. The same procedure holds for
other time-series variables for which there are files.
The time-series borrow edit box specifies an alternative project that is checked to establish
a file if a time-series filename made up of the project name and the appropriate extension is not
found.
2.2.2 Ambient tab
The input table of the Ambient tab is similar to the input table the Diffuser tab. Figure 2.7 is
a sample of the Ambient tab window. Components include:
2.8
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g»nrnnidL.iin=K»jni5T.ini.Eiimt3iBTganuijimiTm.^nr.raB»i».-»J,ivii.i,iii
File Edit Models Stop Run Help
jnlal Protection Agency, 25 Oct 2000
Di[[user:SadogTaseAugOO.vpp.db Ambient C:\Plumes\Sadog ToseAug 00.001.db | Special Settings | Textual Output | Graphical Output ] Surface Discharge Model |
Ambient Inputs
Measurement
depth or height
Currenf
speed
Cuirent
direction
Ambient
salinity(*J
Ambient
temper afure
Background
concentration
Pollutant
decay rate(")
nA
n/r
n/r
An
Depth or Height
Extrapolation (sfc
Extrapolation (btm)
Measurement unit
t.
blent file (si
Filename
|SadogTaseAug00.001.c
SadogTaseAugQI.QOZc
>
F^S^^^HI depth depth depth depth depth depth depth depth
I constant constant constant constant constant constant constant constant constant
I constant constant constant constant constant constant constant constant constant
m | m/s deg psu C ppb s-1 m/s j deg mO. 67/s2
0 0 90 29 30 0 0.5262 _±.
50
-
Time-Series Files (optional)
Borrowtime-series files from project: |C:\Plumes\Sadog Tase Aug 00
Time-series filename
Time increment (hrs)
Cyelinq penod
File measurement unit
click for file
click for file
click for file
click for file
click for file
click for file
click for file
click for file
click for file
.Default project r
2 preftx tor tirr
Figure 2.7 The ambient tab
1. The Ambient-Inputs panel includes the ambient input table, for entering ambient data at
various depths (or heights). Above the data table is an expanded selection table (or header
array) for specifying depth or height mode, interpolation options, and units.
2. An Ambient file list that lists existing ambient files that were added previously; like the list
box on the Diffuser tab, a click on a filename puts the corresponding data on the ambient tab.
Unlike the one on the diffuser tab, this list cannot be used to add or delete files.
3. The Time-series files panel for linking time-series ambient data files to VP, serving the same
function as the corresponding panel on the Diffuser tab (see Time-series input, above).
The ambient input table
This is the large input table in the middle of the tab designed to display ambient water
column data. A convenient property of the table is the way it corresponds to available data, that is,
data need only be entered at depths at which it is available. Blank cells indicate that data are not
available at those particular depths or are not required (n/r columns). The first line need not
correspond to the water surface, nor must the last line equal or extend below the port depth. The data
correspond to actual depths at which measurements were made or inferred. With the exception of
at least one value to define a given ambient property, the cells are best left blank when there is no
data. The input values are all actual measured, or, assumed, values. Unlike the diffuser table base
case, the first row of the ambient table may have empty cells.
2.9
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There are a couple of exceptions, or recommendations. It is recommended that a zero depth
row is specified. Also, to force VP to extrapolate to the bottom, a line specifying the bottom depth
is recommended, even if there are no other data on that line.
VP has an interpolation and extrapolation capability that allows an uncluttered display of the
data. VP's acceptance of blank cells is intended to help give an immediate conception of the
coverage and completeness of the actual data.
These general rules are modified to accommodate time-series file data, explained in more
detail in Section 5.
The header array
VP consults the header array to determine the proper way to interpolate or extrapolate the
data in the ambient data table. For example, if at any time during the simulation the plume element
is below the deepest indicated water column depth (input in the first column or Measurement depth
or height column), VP consults the header array to determine how to extrapolate the ambient data
table to provide the correct ambient value at any depth.
The Depth or Height row of the header array allows one to toggle between depth or height
modes of data input. Depth mode means measurements were taken at distances below the surface.
Height mode means measurements were taken at distances above the bottom.
The Extrapolation (sfc) row of the header array cycles between the constant, extrapolated,
and linear to zero modes of surface extrapolation. Its setting determines how VP will calculate
temperature or other variables between the surface and the first data value. In the constant mode the
value of the property is equal to the first cell value in the column. If there is more than one value
specified in the column, the values in the surface layer are extrapolated from these.
The Extrapolation (btm) row of the header array works similarly for depths between the last
cell value in the column and the bottom.
The Measurement unit row of the header array functions like the units row on the Diffuser
tab. A click on it pops up a list of units from which to choose.
These first three specifications are available for all variables in the header array except the
water column, i.e., the first column. The latter values in the first column are always specified, either
as depths or heights. To change the units in this column, one must first double click on the cell to
put it in the change mode. These are advanced concepts treated in more detail in Section 5.
Run-time efficiency
For computational economy it is desirable to smooth the ambient data to avoid many small
vertical increments in the ambient file. While this is not a requirement, the presence of many vertical
depths will cause VP to more frequently define bracketing depths. This is a complicated process,
involving the Borland Database Engine, that is necessary to create a filled, internal array of values;
running it at every time step can mean a significant difference in performance when many cases are
run.
Creating additional ambient tables
2.10
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Frequently a mixing zone analysis involves several or many ambient scenarios. Unless time-
series files are linked to VP, each scenario is expressed in its own ambient table and associated file.
When a new project is created the ambient table will be blank, except for an assumed value of 0 in
the depth column. As ambient data is stored in a database (direct access) file, the data are stored as
soon as they are entered. The file name is determined by tacitly accepting the given filename or
giving the file a new name using the Save ambient file as command on the File menu. In this way
many ambient files may be created, each one serving as a template for the next.
To facilitate linking many ambient files to other projects it is useful to use the ambient file
naming convention consisting of the appropriate project name, followed by a numeric sequence
(001, 002,...), followed by the extension db, e.g. VP ambient. 003.db. When using the Save ambient
file as command this convention is offered by default and, upon acceptance or change, are added to
the ambient file list. Files named in this way may be added to another VP project en masse using the
Add all xxx command from the pop-up menu shown in Figure 2.4.
Limit on restoring initial ambient table data
CAUTION: As for the diffuser tab, The Edit menu has a Substitute ambient backup file
command for restoring the ambient table to its original state, values that existed when the project
was first opened. For ambient files, this only works for the file at the top of the ambient file list. This
means, effectively, that unless you make copies of the other ambient input files, any changes you
make are permanent.
Time-series ambient input files
The time-series panel on the Ambient tab is similar to the one on the Diffuser tab. The
ambient time-series files must have been created beforehand as discussed below. They are selected
by clicking on the click for file cell, as described above for the diffuser tab. The time-series-files
array is covered in more detail in the section entitled "Time related data, time-series files."
2.2.3 Special Settings tab
The Special Settings tab, Figure 2.8, controls text and graphical output format and other
functions. There are five panels on the tab:
2.11
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Diffuser: Fan-Run-1G.vpp.db ] Ambient: C:\Plumes\Fan-Run-16.QQ1.db Special Settings ] Tent Output | Graphical Output |
11M3 tidal pollutant buildup parameters
Graphics settings
Style —
ff 4-panel
dilution
r concentration
C custom
• Custom graph coords.
(*" Abscissa (x)
f Ordinate 1 (ji)
T Ordinate 2 M
Custom variables
x-posn
Start case for graphs Max detailed graphs
Additional model input
Diffuser port contraction coefficient j
Light absorption coefficient
|0.16
Farfield Increment (m)
[200
UM3 aspiration coefficient
- PDS sic. model heat transfer —
T Low (f Medium
High
NRETELD/FRITELD input variables
Text output settings
• Output medium
f Text Output tab
Output to file
Selection List
Selected Variables
P-dia
Temp
Density
Amb-den
Dilute
x-posn
Time
UM3 output each?? steps |5QO
UM3 maximum dilution reported |lOQOQ
~ UM3 max vertical reversals 1
(• 0 (to max rise or fall)
r 1 (to 2nd max rise or fall)
-UM3 text output format
<• Standard output
C Brief output
Figure 2.8 Special Settings tab with UM3 tidal pollutant buildup parameters components
hidden (not required because UM3 is not the currently selected model).
UM3 tidal pollutant buildup parameters panel
The components on this panel are revealed when
the Tidal pollution buildup option is checked on Model
Configuration panel. An example is shown in Figure 2.9.
The edit boxes must be completed to use the tidal
pollutant-buildup capability. Briefly, in tidal rivers, this
capability makes it possible to estimate the time-varying
background pollution concentration that can cause the
effective dilution of the outfall to decrease. This option is
currently limited to the UM3 model.
LTM3 tidal pollutant buildup parameters
Channel *» N ^ff
Channel seg. length (m)
Upstream dir (deg)
Coast bin (10-99)
Coast concentration
Mixing zone depth (m)
Internal array cells used =
|250
|90
lo
lo
lo
199
Figure 2.9 Tidal buildup parameters.
2.12
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Tidal pollutant buildup details
The first two edit boxes on the UM3 tidal pollutant buildup parameters panel are labeled
Channel width and Channel seg. length. The product of the channel width and the sum of the port
depth and port elevation should represent the cross-sectional area of the channel. The channel
segment length, on the other hand, is arbitrarily assigned. Its length, however, determines the
convergence of the computed background concentration on an optimally high value. VP provides
for a maximum of 200 internal array elements to store the accumulated concentration in cells that
previously passed over the discharge point. If the segment length is large, only a few of these cells
will be used because the tidal excursion will be small relative to the size of the storage cells. This
will result in poor spatial resolution (input effluent will be averaged over large volumes). On the
other hand, if the segment length is too small, 200 array elements will not be sufficient to store the
information and the array limits will be exceeded. If this happens UM3 may stop running and a
larger length will need to be specified. Some experimentation will be necessary to determine a
segment length that is near the smallest value allowed. At the end of the run, VP outputs the number
of internal array cells used. The object of the optimization procedure is to maximize this value near
200, for example, 199 would be the most optimum value.
The Upstream J/>ection edit box is used in conjunction with the Amb current vector
averaging setting (on the Model configuration panel) to help VP determine whether inputted
directions are net upstream or downstream. Here the value of vector averaging should be apparent.
For example, if flows at two depths are upstream and downstream respectively, directional averaging
(the default setting when ambient current vector averaging is not checked) would indicate a
cross-stream component to the direction!
The Coast bin (10-99) edit box identifies the position of the coastal bin along the one-
dimensional tidal channel in which the buildup of background pollution is occurring. During the
simulation, on the flood, any bin that moves upstream through the coast bin has its concentration set
to the value specified in the Coast concentration edit box. The discharge is always initially assumed
to be located in bin 100. The coastline bin number is determined by equating the downstream
volume to the product of the segment volume and the number of bins between the outfall and the
coastline. For example, if the total depth of the channel at the point of discharge is 10m, the channel
width is 100m, and the segment length is 100m, then each bin has a volume of 100,000m3. If the
reference volume of the estuary below the point of discharge is 5,000,000m3 then the coast bin value
would be 50.
The Coastal concentration edit box is used to specify the background pollutant concentration
in the ocean, bay, or estuary to which the tidal channel connects.
The Mixing zone depth edit box identifies a mixing zone "ceiling" at which an output may
be specified, i.e., a depth of interest in the water column at which estimates of concentration are
desired. When this criterion is reached, UM3 outputs a message to that effect.
Additional model input panel
The Diffuser port contraction coefficient edit box is provided to specify the value of the
contraction coefficient for the discharge ports. The discharge coefficient of sharp-edged ports (a
2.13
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cylindrical hole in the diffuser pipe wall) is about 0.61. For bell-shaped ports (flaring inward into
the direction of flow), a value of 1.0 is usually used.
The Light absorption coefficient edit box is provided for specifying the light absorption
coefficient for the Mancini bacteria model. This is the coefficient k^ found in Mancini, 1978, that
describes water clarity. The default value is 0.16.
The Farfieldincrement controls the number of lines output by the Brooks far-field algorithm.
A small value produces more lines and graphic output than a large value. The value specified
depends on the size of the zone of mixing, but, typically might be anywhere from 100 to 1000m.
The UM3 aspiration coefficient specifies the rate at which ambient fluid is entrained into the
plume. The default value of 0.1 is an average value that, historically speaking, was rarely changed
by users of DOS PLUMES. A large value causes more rapid plume spreading and affects other
characteristics, like plume rise.
The PDS sfc. heat transfer radio group specifies the surface heat transfer rate used when
running the PDS surface discharge model. The available options are low, medium, and high
corresponding to low wind and high humidity conditions, "average" conditions, and to windy and
dry conditions respectively.
Text output settings panel
The Output medium radio group is used to specify whether output appears on the text output
tab or is written to a file (the Output to file option). When the file option is selected, the Output file
selection list box appears. Clicking on it causes the Text Output File dialog window to appear that
allows an input file to be selected or input. The default name is VP.txt.
The Selection List drop-down list may be clicked to add or remove variables from the output
variables list shown in the Selected Variables list box. A click on a variable name acts like a toggle,
adding or removing a variable from the text output tab the next time a model is run. To add or
remove a variable, click the arrow on the Selection List list box to get the drop-down list and then
click on the variable you want included or removed from the output.
The UM3 output each ?? steps edit box is used to control the frequency of UM3 output. For
example, a value of 100 causes UM3 to display output after 100 program steps, or full cycles. This
does not affect output when special criteria are met, like when the trapping level is reached.
The Maximum dilution reported edit box serves to limit the maximum number of UM3
program steps. It should be specified to be greater than the maximum dilution of concern,
furthermore, it should be large if model is configured to compute a far-field solution. It limits
computation when conditions do not inhibit plume behavior, for example, a plume in deep,
unstratified water.
The UM3 max vertical reversals radio group controls where the UM3 simulation terminates.
With the to max rise or fall option UM3 terminates upon reaching maximum rise or maximum fall,
depending on input conditions. With the to 2nd max rise orfallUM3 will run to the next maximum
rise or fall. This option is important when a plume still has great potential for rising or falling upon
reaching the first extremum. For example, a dense discharge discharged upward has not completed
the initial dilution process at maximum rise, as it will reverse its upward motion and accelerate
downward
2.14
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The UM3 text output format radio group allows a selection of standard or brief output. Brief
output suppresses the writing of headers and input conditions.
The Close panel button hides the text output settings panel. This button serves to hide the
panel when it is made visible after pressing the Output options button on the Text output tab.
Graphics settings panel
The Style radio group simply selects the graphic panel that is displayed whenever one clicks
on the graphical output tab. It determines the "default" graphic on the graphics tab. This is basically
the same Style radio group that appears near the left margin of the graphics tab, except that the labels
are spelled out.
The Custom graph coords, radio group and the Custom variables drop-down list work in
tandem to specify the output variables plotted on the custom graphic. After one selects Abscissa (x),
the drop-down list is used to specify the corresponding variable to be plotted on the x-axis the next
time the model is run. The same is then done for the left y-axis by first selecting Ordinate l(y)
followed by specifying the corresponding variable from the drop-down list. The procedure is
repeated for the right y-axis, first selecting Ordinate 2(y) followed by selecting the corresponding
variable.
When running multiple cases it is usually desirable to suppress all plotting except the runs
of interest. The Start case for graphs edit box is used to specify the first case that will be plotted.
The Max detailed graphs edit box is used to specify how many additional cases are plotted starting
with the one specified above. These specifications apply to the 4-panel graph only.
NRFIELD/FRFIELD input variables panel
This panel is unfinished.
2.2.4 Text Output tab
This tab presents model output in text form, an example is shown on Figure 2.10. Every time
a model is run, each case, or row, from the Diffuser tab is given a case number starting with 1 and
running consecutively through the last case. In configurations where only one case is selected (base
or selected case) there will be output from only one case, unless time-series files are linked into VP,
in which case there may be many. The Model Configuration panel and Special Settings tab influence
the text output significantly.
Several points are noteworthy. The complete set of input values (from the Diffuser tab) are
only given for the first case, Case 1. Subsequent cases show just the input values that are different
from the previous case. When multiple cases are run they are labeled sequentially (in Figure 2.10
two individual runs were run, consequently, they are both Case 1). For time-series runs, VP assigns
case numbers as it reads input values from the files and runs the corresponding conditions. It
displays the values read from the time-series files in the run header. Depending on the model used,
VP flags where plumes merge, are trapped, reach the surface, and reach the chronic and acute
mixing zone limits. The output can be saved to a file (specified on the Special Settings tab) or
printed using the print option on the File menu. When subsequent runs are made the case count is
2.15
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reset to one and text output for these runs is appended to what is already in the text window. If
previous output is no longer wanted, the Clear Display button may be clicked before making
additional runs.
Diffuser: Sadog TaseAug 00. vpp.db| Ambient: C:\Plumes\SadogTaseAug01.002.db] Special Settings Text Output j Graphical Output j
iCiear text display;! Clear + Output options Numerical only
i>.................;........^..v......;i i i '
Windows UM3. 1/18/2001 4:17:59 PM _-
Case 1; ambient file C:\Plumes\Sadog Tase Aug 00.001.db; Diffuser table record 1:
P-dia P-elev V-angle H-angle Ports Spacing AcuteMZ ChrncMZ P-depth Ttl-flo Eff-sal Temp Polutnt
(in) (ft) (deg) (deg) () (ft) (ft) (m) (ft) (MGD) (psu) (C)(col/dl)
6.0 3.0 0.0 0.0 6.0 19.68 49.0 100.0 49.0 4.8 4.5 30.0 17000.0
Froude number: 1164
Depth Amb-cur P-dia Polutnt Dilutn x-posn
Step (ft) (m/s) (in) (ool/dl) () (ft)
0 49.0 0.0 6.0 17000.0 1.0 0.0;
100 47.88 0.0 39.75 2434.2 6.876 7.117;
200 28.68 0.0 108.3 493.4 33.81 19.51:
248 0.501 0.0 188.3 190.5 87.45 24.81; surface.
Plumes not merged. Brooks method may be overly conservative.
Const Eddy Diffusivity. Farfield dispersion based on wastefield width of 15.04 m
cone dilutn width distnce time
(col/dl) (m) (m) (hrs) (ppb) (ly/hr) (m/s)(mO.67/s2)
53.1976 218.8 51.94 100.0 2.568 0.0 140.7 0.01 3.00E-4
count: 1
4:17:59 PM. amb fills: 2
/ Windows UM3. 1/18/2001 4:19:13 PM
Case 1; ambient file C:\Plumes\Sadog Tase Aug 01.002.db; Diffuser table record 1:
P-dia P-elev V-angle H-angle Ports Spacing AcuteMZ ChrncMZ P-depth Ttl-flo Eff-sal Temp Polutnt
(in) (ft) (deg) (deg) () (ft) (ft) (m) (ft) (MGD) (psu) (C)(col/dl)
6.0 3.0 00 0.0 6.0 19.68 49.0 100.0 49.0 4.8 4.5 30.0 17000.0
Froude number: 11.54
Depth Amb-cur P-dia Polutnt Dilutn K-posn
Step (ft) (m/s) (in) (col/dl) () (ft)
0 49.0 0.08 6.0 17000.0 1.0 0.0;
100 48.09 0.08 37.36 2346.3 7.131 7.213;
200 33.05 0.08 144.8 323.6 51.55 26.06;
238 22.46 0.08 236.8 152.3 109.4 36.27; merging,
263 12.4 0.08 381.2 92.74 179.5 47.98; surface.
Const Eddy Diffusivity. Farfield dispersion based on wastefield width of 39.68 m
cone dilutn width distnce time
(col/dl) (») (m) (hrs)(col/dl) (ly/hr) (m/s)(mO.67/s2)
80.1713 197.7 56.9 100.0 0.474 0.0 425.4 0.05 3.00E-4
count: 1
4:19:13 FM. amb fills: 2
>r
Figure 2.10 Text Output tab.
Users familiar with UDKHDEN and PDS standard output will notice that the VP output for
these two models is abbreviated. However, the complete output is saved in its original format in the
default directory. For DKHW, it is saved as DKHW.out. For PDSWin, it is PDS.out. These files
include output for all cases simulated during the run, they are deleted and re-written each time the
models are run. If this output is to be saved the output files should be renamed before the models
are run again. This is of particular interest to users interested in surface thermal plumes since PDS
prints out the area within surface isotherms in the PDS.out file.
2.2.5 Graphical Output tab
This tab displays output in graphic form. A sample of the 4-panel style of graphical output
is given in Figure 2.11. The Style radio group on the Graphical Output or Special Settings tab is used
to select the style. There are four different styles of graphs:
2.16
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"aaaog laseAuguu.vpp.QD] Amoienc: L:\numes\5aoog iaseAugui.uu£QD| special settings j
Plume Elevation
Ambient Properties
5
10
15
~20
I25
Q30
35-
40
45
50
+ »
,
-t
\
*
*
+ *
.
1
1
•
1
— Amb. density
— Amb. density
* Plume density
* Pfume density
— Verification
14 15 16
Density (sigma-T)
•
240
220 \
200 i
iso;
wo;
i140;
3 120-
Q
100;
so;
60.
40
20
West-East (ft)
10 20 30 40 50 60 70
Horii. Distance from Source (ft)
Figure 2.11 Graphical Output tab.
4-panel graphics
This graphic depicts plume and ambient properties of the chosen cases. The four graphs
include, from left to right and top to bottom: (a) an elevation view looking horizontally through the
water column, (b) a plot showing the density of the plume and ambient as a function of depth (this
is helpful to observe trapping effects), (c) a plan view showing single plumes in the near field
(before merging) and the merged-plume width or waste-field width in the far field, and (d) a plot of
centerline and average dilution versus distance from the discharge (radial distance, or, more
precisely, distance along the length of the projection of the plume trajectory on a level surface). The
solid lines in the plan and elevation views plot the plume centerline, the dots either plot the
"absolute" plume-ambient boundary or the average concentration boundary when Average plume
boundary is checked on the Model configuration checklist.
Dilution graphic
2.17
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This is a summary graphic of end-point dilution. End-point dilutions correspond to predicted
dilutions at specific criteria, notably at maximum rise, upon hitting the surface, and at the mixing
zone boundaries. The triangles represent the dilution at the acute and chronic mixing zones. The
rectangles represent the dilution at a hydrodynamic criterion, usually maximum rise or plume
surfacing, whichever comes first. The mass or volume dilution is plotted unless Graph effective
dilution is checked on the Modelconfiguration checklist and the effective dilution is plotted instead.
The former dilution describes the hydrodynamic mixing efficiency of the plume, the latter includes
the pollutant added to the plume by entrainment and describes the reduction in concentration
achieved within the plume. The two dilutions are equivalent when the background concentration is
zero.
Concentration graphic
The concentration graphic is the inverse of the effective dilution graphic. It always depicts
pollutant conditions at end points (maximum rise, surface hit, mixing zone boundaries).
Custom graphic
This may be a summary graphic if the x-axis variable is Casecount or a detailed graphic if
the x-axis variable is any other variable besides Casecount. To select the custom graphic variables,
see the Graphics settings panel description in Section 2.2.3.
Series radio group
Color facilitates comparing model predictions. Two graph series may be selected, Series 1
or Series 2, corresponding to red or blue. Depending on the selection, values are plotted in one or
the other. The act of specifying a series automatically returns the user to the Diffuser tab since this
is the most common place from which model runs are initiated.
Verify button
Verification data in x-y format can be superimposed on Visual Plumes predictions on the
Graphics tab. Clicking the "Verify" button opens a file dialogue window for locating and opening
previously created ASCII input files. An example of file input data excerpted from the Fan-Run-16
project verification file, Fanl6.txt, is:
2.18
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side view
0.0001 1.0145
0.0068 1.0157
0.0149 1.0158
0.0197 1.0161
0.0264 1.0159
density profile
17.3 0.0
25.2 1.0
Blank lines will cause a space between data (lifted pen). The key words (side, profile, path,
dilution, effdilution, concentration, and generic) shift plotting to the corresponding graphic panel,
namely, the elevation, density profile, plan view, and dilution on the four-panel graphs, and dilution,
concentration, and the generic custom panels. Units should correspond to the ones chosen in Visual
Plumes.
Other controls
The remaining buttons give the user the ability to clear the screen, get help, select other
graphic images (styles), or to apply VP's automatic scaling function.
The Clear all button clears all graphics. The Clear la and Clear Ib buttons clear the
centerline graph and plume boundary graph of Series 1 (red) respectively. The corresponding
buttons clear Series 2 (blue).
The Clear + button clears all graphics and text.
The scaling function (Scale button), applied individually to each style, is handy for
establishing graphic scales that capture all of the plotted points. It works best on single runs.
The To File button creates bitmap files of all seven graphics using the proj ect name followed
by a graphic identifier and finally the bmp extension to build the bitmap filenames. The graphic
identifiers are traj, prof, path, di!4, dil, con, and gen for the trajectory, water-column profile, path,
4-panel dilution, summary dilution, summary concentration, and custom graphics respectively. The
bitmaps can be brought into reports and other applications and do not include the surrounding
Windows material.
As they are bitmaps, the graphics files that are created when the To File button is clicked are
memory intensive. Each file requires about 2Mbytes of memory. Consequently, it is recommended
that these files are handled promptly, either deleted or saved on another medium. Programs such as
Microsoft Paint may be used to convert these files to more condensed formats.
The bitmap files of the 4-panel graphics are re-scaled by VP before they are saved. This
procedure improves the quality of the 4-panel graphics.
Customizing graphics
Other means are available to customize the appearance of the graphs. For example, the
position of the graph may be altered within a particular window (panning) by making a right click
2.19
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with the mouse in that window, holding down the button and dragging the mouse. One can also left
double click on the margins of a graph to display a window that contains various formatting
components and options. These options include changing the titles, setting the coordinate limits,
setting the background color, etc..
Zoom options are also available. A left click on the mouse inside the graph followed by
holding down the button and dragging the mouse creates a fence or rubber band that establishes new
zoom limits. Dragging from lower right to upper left returns the settings to the original values. As
(some of) the settings are maintained by VP in the project list file, it is a good idea to return to the
preferred appearance before exiting VP.
As with other components, a right click on a graph brings up a help screen.
Printing graphics
Graphs can be printed on a graphics printer by selecting Print from the File menu. They can
be copied by using the Alt-Print-Screen key sequence and pasted into a graphics package or word
processor of choice. A control-V, (AV), key sequence is the quick way to paste. Of course, the
graphics bitmap files (see the section on other-controls above) can also be processed and printed.
2.3 Model-specific panels and components
Hidden components
The user should be aware that some of VP's components are configuration dependent, which
means that they are not always visible. For example, the components on the UM3 tidal pollutant
buildup parameters panel on the Special Settings tab are not visible unless the Tidal pollution
buildup option is checked on the Model Configuration checklist on the diffuser tab. The same is true
for the Output file edit box on the Text output settings panel on the Special Settings tab, which is
only visible when the Output to file radio button is selected.
Changing labels
The labels on the diffuser and ambient tables are similar, changing depending on the target
model which is identified is identified under the model logo on the diffuser tab (PDS, UM3, etc.).
Other components change depending on context. Noteworthy is the save-file-as command
on the File menu, which changes from Save project as to Save ambient file as depending on whether
the command is issued from the diffuser or ambient tabs respectively.
Displaying the Froude number and other parameters
Some components require user intervention before they are completed. For example, the
densimetric Foude number for a particular case is not displayed correctly until the case is established
by clicking on the appropriate line in the diffuser table and until pressing the Parameters for selected
row button that also serves as a label for the parameters panel.
2.20
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2.21
-------
3 Entering Data
The How to proceed Window
When creating a project for the first time the How to proceed window appears to allow a
target model to be specified. This is done so VP can identify the variables, or columns, required by
the target model. If one clicks on different models in succession, the column labels can be seen to
change as some of the columns go from showing a label, like Time increment, to n/r for not required.
Once a model is accepted, the required columns can still change. For example, entering a value
greater than one for the number of ports will change the port spacing column label from n/r to Port
spacing. The model configuration options can have a similar effect. Notice that the column labels
may change again if subsequently models other than the initial target model are run.
General data input
General Windows editing conventions apply to VP. This includes selecting and editing text
and numeric values. In the numeric tables some database program conventions apply as well. Fine
editing can be achieved by first selecting a cell and then clicking a second time to highlight only the
numeric portion. The cursor can then be used move about the value to edit it.
Experimentation is encouraged. With the cursor in a table row, the Ctl-Delete key sequence
will delete a full row of data. The Insert key will insert an empty row. Cutting and pasting in the
input tables is not presently supported.
3.1 Diffuser Tab
General considerations
In VP input focuses first on the diffuser and flow table (or, simply, the diffuser table) on the
Diffuser, Flow, Mixing Zone Inputs panel. However, it is useful make notes in the Project memo box
and it is generally important to check the proper selections on the Model Configuration checklist,
the Case selection radio group, and other settings on the diffuser tab.
Once a model is specified it is recommended that the units are selected. The default units are
mainly SI (generally MKS) units. They may be changed by clicking on the unit and selecting the
desired unit from the pop-up list of available units.
VP cannot run any model until all required values for the base case, consisting of one
completed row (the top one) in the diffuser table, are provided. If all required values are not defined,
an error message will appear. The mouse and arrow and tab keys may be used to navigate the
diffuser table. Values may be typed in immediately upon entering a cell, if a value already exists it
will be replaced by the new one. See the tutorials for more editing instructions.
Additional runs (on subsequent rows) inherit all the base case information except values that
are specifically changed in subsequent rows (except that the sequence is different when the All
i.l
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combinations option is selected). Pressing the down-arrow key when the cursor is located in the
bottom row of the diffuser table creates a new row.
3.1.1 Diffuser table variables
The variables listed in the diffuser and flow table are as follows:
1. Port diameter: this is the port discharge diameter (abbreviated P. dia. on the Text Output
tab). If PDS is the target model it is labeled Conduit width. On the Text Output tab, P. dia.
should be interpreted to refer to the plume diameter, which is equal to the port diameter at
the origin.
2. Conduit depth: this variable is required by PDS which assumes a rectangular surface
discharge. The column is not required by the other models.
3. Port elevation: this is the vertical distance between the port and the bottom of the water
body. This variable does not have a major effect on model prediction and can sometimes be
changed to avoid related output messages.
4. Vertical angle: the discharge angle relative to the horizontal with zero being horizontal, 90
being vertically upward, and -90 being vertically downward.
5. Horizontal angle: the horizontal port discharge angle relative to the x-coordinate. Assuming
that the default units (deg) are used, zero is in the direction of the x-coordinate (flow towards
the east) and 90 in the direction of the y-coordinate (flow towards the north). This default
coordinate system is essentially the scientific convention in which eastward corresponds to
the x-coordinate direction and angles increase counter-clockwise. An optional unit is labeled
N deg and conforms to the surveying standard in which north is zero and angles increase
clockwise. For PDS the horizontal angle is the discharge angle relative to the
x-coordinate.
6. Num of ports: the total number of equally spaced ports on the diffuser. If there are multiple
ports, they are all assumed to be on one side of the diffuser. Modeling opposing directions
generally requires at least two separate runs. For T-shaped risers with two ports on each
riser, a conservative approximation is to assume all the ports are on one side of the diffuser
with the spacing equal to half the spacing between risers. (When running NKFIELD, which
is based on T-riser experiment, VP makes the necessary adjustments to this convention.)
7. Port spacing: the space between ports. This is assumed to be the same for all ports. This
variable is not required unless the number of ports is two or more. NRFIELD requires at
least four ports. See Item 6, above.
8. Start time: the starting time for a time-series run. (If there are linked-in time-series files, time
= 0 is assumed to be the common origin for all files and runs.)
9. Ending time: the ending time for a time-series run.
10. Time increment: the time increment for a time-series run.
11. Acute mix zone: the distance to the acute mixing zone limit or CMC. Output is flagged when
this distance is reached. When the Brooks far-field solution option is checked, the output
intermediate output distances are specified on the Special Settings tab.
12. Chronic mix zone: the distance to the chronic mixing zone limit or CCC. Output is flagged
when this distance is reached or when the plume reaches the surface. For PDS this label is
O O
3.2
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changed to Region of interest, and represents the distance along the plume centerline where
simulations are to stop.
13. Port depth: the distance from the surface to the port centerline. (This variable is optionally
a time-series variable.)
14. Effluent flow, the total volumetric flow from all ports. (This variable is optionally a
time-series variable.)
15. Effluent salinity (density): either the effluent salinity or density depending on the units
selected. Note that the column label changes when units are changed from salinity to density.
Also, when converting from salinity to density units, or from density to salinity, the
temperature must be defined. (This variable is optionally a time-series variable.)
16. Effluent temperature: the effluent temperature. If salinity is selected in 15, above, VP
calculates the effluent density from the salinity and temperature. (This variable is optionally
a time-series variable.)
17. Effluent cone: the concentration of the pollutant of concern, or tracer, in the effluent. (This
variable is optionally a time-series variable.)
3.2 Ambient Tab
Concerning data input to the ambient table, it is emphasized again that only the first column
in this table must contain values in each indicated row, which must not number less than two. All
the other required columns must contain at least one value (to define a value for that variable),
however, it is recommended that these values only be specified at the depths at which they were
measured. Cells in the column corresponding to depths at which the given variable was not
measured should be left blank. If no measurements are available the data may be synthesized. In that
case, if the variable is to be held constant, only a single value need be input in the column, which
can be in any row with a specified depth.
All variables on the ambient table with the exception of the first column are optionally
time-series variables.
3.2.1 Ambient table variables
The variables listed in the ambient table are as follows:
1. Measurement depth or height: This column holds the data at which water column
measurements are available, generally depth below the surface but they can also be heights
above the port. If data are measured at only one depth, a second depth must still be specified.
If data are synthesized, i.e., data are assumed or inferred but not actually measured, at least
two depths must be specified in the column, even though the other columns may contain only
one value. A depth specifying the bottom will assure that ambient density is plotted to that
depth on the density stratification profile graphic and that extrapolation, if ordered, is
performed. An arbitrary number of rows may be specified but VP runs more slowly the more
depths are used and more than 20 depths are not recommended due to the size of the internal
ambient array.
3.3
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2. Current speed: the speed of the current at the specified depth.
3. Current direction: the direction of the current at the specified depth. For angle conventions
see the discussion of the horizontal angle in the Diffuser table variables section above.
4. Ambient salinity (density): either the effluent salinity or density depending on the units
selected. Note that the column label changes when units are changed from salinity to density.
Also, when converting from salinity to density units, or from density to salinity, the
temperature must be defined.
5. Ambient temperature: the ambient temperature. If salinity is selected in 4, above, VP
calculates the effluent density from the salinity and temperature.
6. Background concentration: the concentration of the pollutant of concern, or tracer, in the
ambient water column at depth.
7. Pollutant decay rate (solar radn): Like salinity and density, this is a multi-purpose column.
Decay rate is indicated on the header when the top three units (per sec, s"1; per day, d"1; or
T90hr) are selected. As an alternative, a selection of the ly/hr (langleys/hr) unit invokes the
Mancini model (1978) for calculating decay rate and changes the header to Pollutant solar
radn. The model is a four stressor model including salinity, temperature, water column light
absorption, and solar radiation.
8. Far-field current speed: the average speed of the current over the time period required for
the plume element to travel from source to receptor site. If the receptor site is nearby, the
value of this variable can be often assumed to be the same as Current speed., however, it
should not be zero as this will imply infinite travel time and cause an error.
9. Far-field current direction: the direction of the current over the time period required for the
plume element to travel from source to receptor site. For angle conventions see the
discussion of the horizontal angle in the Diffuser table variables section above.
10. Far-field diffusion coeff: This is the diffusion coefficient used by the Brooks far-field
algorithm. A generally conservative default value is considered to be 0.0003m2/3s2. Two
solutions are offered, the 4/3 Power Law and the Constant Eddy Diffusion algorithm, the
former for open water and a more restrictive one for inland channelized waters. The 4/3
Power Law solution is output when the 4/3Eddy variable is placed on the Selected Variables
list on the Special Settings tab, otherwise the more conservative solution is output. The
coefficient affects only horizontal dispersion, vertical dispersion is assumed to be much
smaller.
3.2.2 Creating Ambient tables
For creating additional ambient tables refer to the sub-section titled Creating additional
ambient tables in Section 2.2.2.
When multiple ambient files are linked into a project, as is apparent by the presence of
multiple filenames in the ambient file list maintained on the diffuser and ambient tabs, it is useful
to remember how to access the other files. Clicking on the desired file name in one of the lists closes
the current ambient file and opens the newly selected one. When the Base or selected case radio
button is pressed, the model will run that case with the ambient conditions contained in the current
ambient database file.
i.4
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3.3 Database Files
Data in the diffuser and ambient tables are stored in database binary format. The files,
bearing the db extension, are compatible with Paradox and other database applications, in which the
archetypal files were set up. If they are manipulated outside of VP, one should be aware that each
closed db file is headed by several rows of data that represent units and other information. If these
are changed inadvertently or are lost in a computer crash there generally will not be loss of data.
Information on units is also stored in the proj ect list file (bearing the 1st extension) that VP maintains
upon exiting a project, so that, even after a crash, VP can usually re-establish the correct database
table information. The signs for this problem are usually clear, an abnormal termination and a re-
establishment of the default units, however, bugs may exist that would obscure the problem. If VP
infers the wrong units the Label only radio button may be selected to correct unit labels without
affecting the values in the column. Once completed, the Convert data radio button should be re-
selected. The Reset diffuser headers and Reset ambient headers comments are available on the Edit
menu for the rare times that data corruption has occurred and diffuser and ambient labels can be re-
established.
The same comments apply to the ambient table.
3.4 Files and Filename Conventions
Project files
A Visual Plumes project consists of a single diffuser database file (a binary file with the db
extension), one or more ambient database files (also with the db extension), and, a "list" file bearing
a 1st extension. If a list file for a diffuser project file is not found, VP creates one. The list file stores
information on the way the project was last modified, for example, many customized graphics
settings are stored in the list file.
Optionally, a VP project may have one or more time-series files associated with it. These
files have variable extensions associated with them than indicate the kind of data that they store, for
example, file TreamentPlant.flo would be a proper name for a time-series file containing flow data
(see the section entitled "Example time-series filenames" below).
VP also creates a file called VPsetup. This file is used to store the name and path of the last
project accessed by the user.
Filename conventions
The diffuser database filename consists of project name followed by the extension .vpp.db.
Given the filename VP plume l.vpp.db, VP plume 1 is the project name, vpp is an abbreviation for
Visual Plumes Project, and db is a standard extension for a database file.
In completing the proj ect file-creation process, VP automatically creates two additional files.
The first appears on the Ambient tab consisting of the project name followed yyy.db, where yyy is
a unique numerical code like 001, 002, etc.. This file may be used as a template for additional
ambient files identified by different numerical constants.
3.5
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The numerals may be used by VP to place a series of ambient files on the Ambient list tables.
By right-clicking on the ambient file list, VP is able to automatically attach ambient files using yyy
as a counter. The same project name is generally recommended for both ambient and diffuser
time-series. However, sometimes it is handy to reuse files from other projects and VP does allow
ambient files from other projects to be listed.
The time-series filename suffix (or extension) is unique to each variable. Given that the
numeric extension yyy is 001, project time series files might have might be named as follows:
Example time-series filenames
Project name.dep Port depth
Project name.flo Effluent flow
Proj ect name, sal Effluent salinity
Proj ect name.tern Effluent temperature
Project name.pol Effluent pollution concentration
Project name.001 .spd Current speed at the diffuser
Project name.001 .dir Current direction
Project name.001 .sal Ambient salinity
Project name.001.tern Ambient temperature
Project name.001 .pol Background (ambient pollutant) concentration
Proj ect name.001 .rat Pollutant decay rate (or solar radiation)
Project name.001 .far Far-field current speed
Project name.001 .fad Far-field current direction
Project name.001.dis Far-field diffusion coefficient
J.C
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4 Introductory Tutorial
4.1 Important mixing zone modeling terms and concepts
Outfalls and diffusers. plumes and jets
Waste water is discharged through a myriad of outfall structures that can differ in many
respects. However, all waste streams that are discharged from outfalls share this basic property: in
operation all form a single or multiple streams that can be distinguished from the ambient receiving
water by some physical properties, notably by a velocity that differs from the ambient current and
by the concentration of one or several properties, except in the degenerative case in which outfall
velocity and current velocity and concentration of properties are perfectly matched.
Schematic views of outfall and diffusers
Figure 10a.
The outfall tumel is
bored through bedrock, arxt
the diffuser section of the outfall is
located along the final 1.25 rntes of trie
structure.
Figure 4.1 A schematic of the Boston outfall tunnel beneath Massachusetts Bay. (Massachusetts
Water Resources Authority [MWRA], 2000)
A general appreciation of an outfall can be obtained from schematic drawings of the recently
completed Boston outfall. This outfall consists of a 15km tunnel bored through bedrock (Figure 4.1)
designed to carry treated waste water ranging up to 44mV1 (1OOOMGD) from land-based collection
and treatment facilities to a distant location in Massachusetts Bay. The outfall tunnel terminates in
a diffuser section consisting of over 50 risers, or vertical shafts (Figure 4.2). Finally, each vertical
4.1
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shaft is capped by a turret that has eight discharge ports
spaced evenly around its circumference
(Fig. 4.3). When operating as intended, the fluid
discharging from any given port forms a jet or plume that
mixes with the ambient water, yielding the dilution that the
outfall is designed to facilitate.
The building block of a mixing zone analysis
A plume from one of the single ports in Figure 4.3
may then be seen to be a representative example of an
effluent discharge. While the port is round in cross section,
other discharge cross sections could be rectangular, like the
cooling canal of a power plant, or ragged, like a natural
stream discharging to a larger water body. In fact, if the
densimetric Froude number of one of the plumes in Figure
4.3 were less than unity (< 1.0), then the fluid would be so
buoyant that it would rise to the top of the discharge port
and have an elliptical cross section. In this case ambient
water may actually flow into the outfall under the plume,
causing an effect in sea water known as saltwater intrusion,
which can cause various problems in outfalls. Rubber flex
valves that open up with increased flow have been
developed to increase the Froude number by reducing the
port cross-sectional area in low flow situations. They also
prevent the backflow of saltwater by acting as a check-
valve.
A vertical discharge with Froude
number less than one may briefly decrease
in radius. In weak current the plume would
have an hour glass shape.
As can be seen in Figure 4.1,
multiple plumes are subject to complex
behavior; they interact, or merge. Still, a
single port (stream, conduit, seep, etc.) and
its plume are the building blocks of any
mixing zone analysis.
Riser
Figure 1 Ob. The 55 nsers carry effluent
from ths deep rock outfall tumel LP to tfie
diffteef- haads at tba seafbor.
Figure 4.2 Outfall riser (MWRA,
2000)
Diffuser head
Entrainment and dilution
The process of mixing ambient
fluid into the plume is called entrainment.
The dilution process and entrainment are
Figure 10C. The drffuser heads each dis-
perse the effluent through eight ports.
essentially synonymous. An understanding „. .,„ ... ... . s^^m \ OAAA\
J J •* & Figure 4.3 Turret with multiple ports (MWRA, 2000)
4.2
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for the driving force for this mechanism may be obtained by studying the turbulence material on the
Visual Plumes CD.
Pure jets are concentrated streams of fluid flow that possess no buoyancy, i.e., their density
is the same as that of the ambient fluid. They are momentum jets. Pure plumes, on the other hand,
initially possess only buoyancy. Most waste water discharges possess both momentum and
buoyancy. Movement through the water column, often in combination density stratification and
sometimes the with nascent density effect, can lead to plume buoyancy in portions of the plume
trajectory where no buoyancy exists at the source.
Effective dilution
Outfalls rarely carry pure product. Generally a wastewater stream consists primarily of water,
the carrier fluid, which contains undesirable constituents, the pollutants. Traditionally, the dilution
process focuses on the mixing of the carrier fluid with the ambient fluid, usually water mixing with
water. However, in recent years it has been recognized that what is most important is what
concentrations of pollutants exist in the receiving water after the dilution process has terminated.
If both effluent and ambient waters contain pollutants the dilution ability is reduced until it becomes
zero when the ambient water pollutant level is at or greater than the water quality standard. This
concern is at the heart of the Total Maximum Daily Loading (TMDL) determinations. When
modeling a discharge to a body of water one also would want to consider other pollutant discharges
and possibly mixing zones in that water body, whether or not the other mixing zones coincide with
the mixing zone being modeled.
The effective dilution (Baumgartner, Frick, and Roberts, 1994) addressed this concern by
introducing the concept of effective dilution, which measures not the dilution of the carrier fluid but
the dilution of the pollutant. The effective dilution is the ratio of the effluent concentration to the
concentration of the plume at the point of concern, like the mixing zone boundary. The effective
dilution implies a rigorous, total mass balance of the pollutant, providing that the background
pollution concentration in the receiving water is accurately described (refer to the next section on
how modeling assumptions affect the estimation of effective dilution). It may be possible that plume
models, such as UM3, in conjunction with field data that accurately describe background
concentrations in the vicinity of the outfall, may be used to satisfy some or many of the requirements
of the simpler TMDLs.
The plume element
One may imagine that a control volume, or plume element, can be established that wraps
around and cuts through the plume, defined by the plume surface and by two cross-sectional slices
through the plume. If plumes were cylindrical in shape the plume element might be compared to the
shape of a tuna can. However, generally plumes bend in the current or from the effect of buoyancy
and they tend to grow in diameter. Therefore, a more general conception of the plume element is a
wedge-shaped portion of a bent cone.
For mathematical modeling purposes the length of the plume element is small but the
diameter can grow to be comparable to the depth of the water column. The plume element is a sort
of mathematical hybrid. This has important implications on estimating effective dilution when the
4.3
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background concentration is stratified, which might occur if the background is produced by other
sources in the area. Some plume models, like UM3, assume that the concentration of the entrained
fluid at any point along the trajectory is defined at the depth of the center of the round cross-section
of the plume element. However, often most of the entrainment occurs along the upstream surface
of the plume element, which will generally be at different depths. Sometimes, the only way to
accurately estimate effective dilution is to alter the background concentration profiles to compensate
for knowledge about where the entrainment surfaces are in the water column.
4.1.1 Properties that affect entrainment
The plume issuing from any given port in Figure 4.3 may be considered to be a prototype
of all effluent discharges. Even though this one port is only one of hundreds belonging to the outfall
diffuser, and many diffusers are simply straight pipes with holes drilled in the sides, and outfalls are
natural channels, the behavior and properties of its plume are representative of this collection of
plumes and other discharges.
Diffuser properties that affect entrainment
Figures 4.1 to 4.3 suggest that specific diffuser and ambient properties act to enhance or
inhibit dilution. The diameter of the port affects the effluent velocity and the surface to volume ratio
of any isolated plume. Similarly, the orientation of the port modifies the plume traj ectory which may
enhance dilution by lengthening the travel distance. The depth of discharge will have similar effect.
Other less obvious factors contribute to enhancing entrainment, including the spacing between ports.
The larger the spacing the greater the path over which plumes do not interact, increasing the surface
area over which clean water can cross the plume surface.
Some port properties, notably the horizontal angle, affect plume behavior and entrainment
by changing the orientation of the plume to the ambient conditions.
Ambient properties that affect entrainment
Just as diffuser properties affect entrainment, it is easy to see that ambient properties do also.
High current speeds deliver more ambient fluid to the surface of the plume and can act to increase
the shear between plume and ambient fluid that contributes to the production of turbulence that will
directly affect dilution. The current direction, like the port orientation, can affect the path of the
plume through the ambient fluid and hence the exposure the plume has to the ambient fluid.
While current can be seen to act directly on the plume surface, thereby enhancing
entrainment, the effects of density stratification are less obvious. Often jets and plumes will have
or will acquire a vertical component of motion. For example, a buoyant plume discharged
horizontally will begin to accelerate vertically and bend upward. The density of the plume element
will frequently differ from the ambient fluid at that depth. The entrainment process will tend to
equilibrate the densities. If the ambient fluid is not density stratified the plume will asymptotically
approach the density of the ambient fluid, without ever quite attaining the same value. Hence, in
4.4
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unstratified fluid the plume will tend to rise or sink, depending on its density, until it reaches the
surface or the bottom.
If the ambient fluid is density stratified, then the plume element can come to density
equilibrium at some intermediate depth in the water column, not at the surface or the bottom. This
is called the trapping or trap level. For example, a buoyant plume discharged near the bottom will
generally rise and gradually approach the density of the receiving water. Suppose it has acquired an
average density of p at some depth z, then, since the fluid is density stratified, it can be seen that
at a shallower depth, to which the plume element is rising, the density will be less than p .
Consequently, the plume can pass through a trapping level and change its buoyancy, going from
positively to negatively buoyant. The plume will then sometimes undergo a wavelike (Brunt-
Vaisala) oscillation, passing repeatedly through the trapping level.
Salinity and temperature are important state variables (state referring to the condition of the
fluid, as in equation of state that determines the density of water). Thus salinity and temperature are
two important variables that affect plume buoyancy. The non-linearity of the equation of state can
cause unusual density effects, including double diffusion and nascent density effects. Fresh water
near the freezing temperature and salt water brines are two fluids that can reverse their buoyancy
during the entrainment process. For this reason, it is sometimes important that models using linear
equations of state are not used for some plume applications.
The level of turbulence in the ambient can also enhance entrainment, especially after the self-
generated turbulence within the plume has dissipated due to loss of plume kinetic energy (or high
velocity) through the entrainment process.
Effluent properties that affect entrainment
Effluent properties that affect entrainment include salinity and density, as these determine
the density of the plume element. Another obvious effluent property that affect entrainment is the
flow rate itself. Generally speaking, the more fluid is forced through a given port the less diluted the
effluent will become. However, unusual combinations of flow, current, and density stratification can
sometimes cause conditions that will cause higher flow plumes to penetrate into unstratified layers
where dilution will proceed without hindrance.
4.1.2 Properties that affect effective dilution
Some properties are not important to the hydrodynamics of the plumes and the dynamics of
mixing and dilution per se, but still affect the concentration of the pollutant, in other words, they
help determine the effective dilution. It is useful to remember that the effective dilution is the ratio
of the effluent concentration to the plume concentration, whether average or centerline values, at a
point of interest, often a point on the mixing zone boundary. The effective dilution is a true indicator
of pollution concentration in terms relative to the effluent concentration.
Effluent and ambient pollutant concentration
The most obvious property that controls the final concentration in the plume element is the
effluent concentration. Using UM3 as an example, the plume element concentration is a linear
4.5
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function of the effluent concentration. An increase in the latter results in a proportional increase in
the plume element concentration.
It may be less obvious that the ambient concentration affects the effective dilution. The
entrainment process mixes ambient carrier fluid into the plume. With the carrier fluid comes any
pollutant mass that is contained within it. In the final analysis, entrainment of polluted ambient fluid
is like an additional contribution of pollutant to the effluent flow. Its effect on determining plume
pollutant concentration is not as simple. The ambient concentration acts more like a floor for plume
concentration. Thus, if the effluent concentration is lOOppm and the ambient concentration is Ippm,
no matter how much the carrier fluid is diluted by ambient fluid, the concentration in the plume will
never fall below Ippm and a limit on the effective dilution will be 100.
Mixing zone boundaries and other variables
The distance to the mixing zone boundary will also modify the effective dilution. Variables
such as start time used with time-series input affects it by determining the inputs at the specific times
of interest.
Finally, the pollutant decay rate and far-field current help determine the effective dilution.
The decay of non-conservative pollutants occurs independently of the hydrodynamic mixing
processes in the plume. Pollutant decay is a function of time. Changing the units on the pollutant
decay column to langleys per hour causes VP to calculate decay rate based on solar insolation, light
absorption, salinity, and temperature.
The far-field current affects plume concentration indirectly. Mixing zone modeling focuses
inherently on concentrations measured or predicted at distances measured relative to their orientation
to the source. These distances and the far-field current are used to estimate the travel time between
source and receptor site.
4.1.3 The dilution and ambient tables as property repositories
Most of the diffuser, effluent, and ambient properties that affect entrainment and effective
dilution have a column devoted to them in either the diffuser or ambient tables. These tables are the
primary place for inputting the data that are essential to simulate the plumes that factor into a mixing
zone analysis.
4.2 The One-port example
This example demonstrates how to set up Visual Plumes and to use it to analyze a single port
plume simulation. It is highly recommended that the user runs VP while reading this tutorial.
4.6
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4.2.1 Starting and exploring VP
Starting VP
The Visual CD has a subdirectory called "Visual Plumes (VP) Setup" that contains an
executable program called setup.exe that can be run to install VP. The default options, that are
recommended, will establish the software in the target subdirectory called c:\plumes (or other drive
or directory). Of course, the default name, Walter Frick, and company, USEPA, should be replaced
by your own name and business. If case of problems send email tofrick.walter@epa.gov .Tor more,
see the subsection entitled "What happens when things go wrong?" below.
After setup is complete, an examination of the plumes subdirectory will reveal several
applications programs including Plumes.exe. This is Visual Plumes which can be renamed if
desired to VP or anything else. Other files include a number of prepared examples, this single-port
example is not one of them. Double clicking Plumes.exe executes VP. An introductory message
appears that gives some information, most importantly, it identifies the Windows settings for which
VP is designed.
Because the file Vpsetup is not one of the installed files, VP is unable to establish a previous
project, therefore it creates one. The next action is to reveal the How to proceed window (Fig. 2.2)
which is used to define the target model, the default is UM3. As the window sometimes appears
between projects, there are two columns from which to choose the target model. If chosen from the
first column, a click will clear any graphics and text output that is left over from a previous run. In
this way output from separate projects can be discarded or retained.
Note that by clicking on the different models before exiting the How to proceed window will
show that the selection affects the headers on the diffuser table. This happens because different
models require different inputs.
Tab identifiers
A glance at the diffuser tab at the top of the screen should show the name of the file " VP
plume O.vpp.db", Figure 4.4. This is the default name that VP creates the first time a project is
started. If a file by that name existed, VP would increment the zero to one, and so forth, until a
unique project name is found. The extension vpp identifies the file as a VP diffuser project file and
the extension db is a reminder that this is a binary database file. Notice that the project path and
filename also appear in the Project box, without the extensions, and in the time-series "borrow"
boxes on the diffuser and ambient tabs.
Ambient: cAplumesWP plume 0.001. db | Special Settings | Text Output] Graphical Output ] Surface Discharge Model ]
Figure 4.4 The VP tabs. Each entire tab page is often itself referred to as a tab.
Similarly, the ambient tab should show the name of the file "VP plume O.OOl.db". This is
also a default name. The three-letter numeric sequence is useful when several ambient files belong
to the same project. Notice that the ambient file name also appears in the Ambient file list edit box,
where, eventually, it could be one of many filenames.
4.7
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Changing the project name
It is a good idea to give projects meaningful names. This can be done by picking the Save
project as command off the File menu and typing the project name "One port" into the edit line of
the Save Project File as dialog window that appears. The original project files will not be erased in
the renaming. They can be discarded through the quitting-time Pre-exit: File Editing Dialog Window
or from a directory management application, like Windows Explorer.
Exploring Visual Plumes
Before entering data it is instructive to look over the interface and to click on the separate
menus and tabs. Except for default values, the VP tabs are effectively blank.
On the diffuser tab, it is instructive to note the "configuration" radio-button groups and
checklist at the upper right quadrant of the diffuser tab. Click on the appropriate items such that VP
will jump to the Graphical Output tab after running one of the models, the Units Conversion
selection is Convert data, no special options are checked, and Case selection radio group shows that
VP is set up to run the base or a selected case when a model is picked to run.
The model icon is the same for each model; the text below it shows the target model that is
selected. The default model is UM3. The Parameters for selected row panel in the lower left hand
quadrant states there is one port and identifies the case number (1). The referenced case is identified
by a triangle (»•) to the left of the first row in the diffuser table. This first row, row 1, is the base
case. Close examination reveals that the label Parameters for selected row is on a button. Provided
the first row is filled in, a press of the button will calculate three important parameters, the
(densimetric) Froude number, effluent density, and port velocity.
The Special Settings tab is also important. Similar to the columns on the diffuser and ambient
tabs that show "n/r" when a variable is not needed by the target model, some of the information on
this tab is hidden to reduce confusion. In particular, the UM3 tidal pollutant buildup parameters
panel is blank. Its components only appear when the Tidal pollution buildup option is checked on
the diffuser tab's Model Configuration checklist. Similarly, the dialog box that appears when the
Output to file radio button is pressed is hidden when output is to the console (in other words, to the
Text Output tab).
Also important is the Selected Variables list, which shows the variables that are currently
on the "output-variables" list. The drop-down list immediately to its left may be used to place
variables on the list or to remove them. The default list includes the "P-dia", which should be
interpreted to be the port diameter at the point of origin and the plume diameter at subsequent
simulation intervals. Finally, the default value of the Diffuser port contraction coefficient edit box
is 1; this corresponds to a discharge that is shaped by a bell-shaped orifice so that the port diameter
closely approximates the initial plume diameter. There is no vena contracta effect. A value of 0.61
represents a discharge from a knife-edged port in which the vena contracta effect is pronounced; the
minimum area of the plume cross section is 0.61 times the area of the port.
The remaining tabs are basically blank. It may be worthwhile to push the Style radio buttons
on the Graphical Output tab to get an idea for the graphics that are available. The cus abbreviation
identifies the panel that can be customized on the Special Settings tab, in a manner similar to adding
variables to the output variables list.
4.8
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Context-sensitive help
Most components on the interface have help topics associated with them which are revealed
by placing the cursor over the component and clicking the right mouse button. The status line at the
bottom of the application is also a useful source of information. The context-sensitive help is not
fully updated as of this writing and may differ somewhat from the information provided herein. The
help topic in Figure 4.5 is obtained by right clicking on the ambient table, selecting Help from the
popup menu, and clicking on the Far-field diffusion coefficient hypertext topic.
s^" wispdelphi
File £dit Bookmark Options jHelp
Helpjopics Back I Print
Far-field diffusion coefficient —j
a A coefficient used in the far-field algorithm.
More: This coefficient is used in Brooks far-field equation which predicts effective
dilution in the far-field plume.
a =e o/b4/3
where
a= the far-field diffusion coefficient
b= width of the plume field at the end of initial dilution
t= the time of travel from the point of the end of initial dilution to the point of interest
For coastal areas of known high energy dissipation features, or in many
geographical areas at certain times of the year, a, may have a value as high as
0.0005 m 2/3/sec. In less turbulent situations a may be as low as 0.0001
m2/3/sec, thus the user has many options to employ in generating more or less
conservative estimates of far-field dilution. Small values of a yield the most
conservative estimates of far-field dilution.
I
Figure 4.5 Help topic one the far-field diffusion coefficient.
Exiting VP
Before beginning the one-port example problem, it is instructive to exit and re-enter VP. One
exits by choosing the Exit command from the File menu (or the Windows X). Before shutting down
VP displays the Pre-exit: File Editing Dialogue Window. Choosing either the Close or Cancel
buttons terminate VP. The keystroke (carriage return) does the same thing. The purpose of
the dialogue window is to provide an opportunity to dispose of unwanted files. This can be done by
4.9
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selecting files for disposal followed by pressing the key. The Files of type pull-down list
provides additional extension filters to help select different files for disposal. The dialogue window
is a convenient way to dispose of the default files that were created before they were renamed.
At of this writing, a renaming of the Open button to Close has been unsuccessful. Similarly,
the Cancel remains even though its function also closes the application.
NOTE: VP Version 1.0 and above has an Exit without saving option.
4.2.2 Problem description
This example might represent a screening, or preliminary, test used to determine whether or
not the discharge is likely to exceed water quality criteria. Based on the findings a decision to
conduct further analysis may be made.
Effluent variables
The example for this tutorial is a single-port discharge to coastal marine receiving water.
This is a relatively small discharge of only 0.05 MGD (million gallons per day). The depth of the
discharge below Mean Lower Low Water (MLLW) is 49m. The influence of tides is ignored. The
effluent is "fresh" at a temperature of 25C. The pollutant is conservative, which means it does not
decay with time. It could be a metal, in any case, it is discharged at a concentration of lOOppm. Note
that these parameters are shown below the green headers on the diffuser table.
Diffuser and mixing zone variables
The outfall consists of a pipe that terminates at a pipe-end port 5cm, or 0.05m, in diameter.
The port is directed upward slightly at an angle of 20deg, perhaps to prevent scouring of the bottom.
The pipe points towards the north, in the direction of the prevailing current, and is one meter above
the bottom at the orifice. (The height above the bottom is a minor variable that is often estimated.)
As it is a simple pipe opening, there is only one port.
Two mixing zones are established for the pollutant, one at 10m and the other at 100m,
corresponding to the boundaries where acute and chronic criteria met, respectively. The mixing zone
is defined as a circle around the end of the outfall pipe. Most of the input is shown in Figure 4.6.
Ambient conditions
As is explained above, this is a discharge to marine water. It is presumed that conditions of
concern are well represented by average conditions (one scenario). The current is in the northward
direction, which means that the flow is towards the north. The current speed, possibly representing
the 10th percentile current, is lOcm/sec. The salinity is typical of ocean water at 33psu (psu is an
abbreviation for Practical Salinity Units which is essentially identical to parts per thousand, or o/oo).
The ambient temperature is 15C and the background pollutant concentration is zero.
4.10
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Diffuser, flow, Mixing Zone Inputs
Port
diametei
tiA
Port
elevation
Veitica
angle
Hor
angle
Nun of
ports
n/i
n/i
rt/l
n/i
in m m deg deg
m s
s m in m
1 20 90 1
Figure 4.6 Project diffuser table with port depth and effluent concentration still undefined.
Vertical
angle
deg
Hor
angle
Mum of
ports
20
4.2.3 Inputting the data
The diffuser table
For input parameters given in the primary units (mostly SI, or
MKS, units) in the problem description above, Figure 4.6 shows
diffuser (yellow, left) and flow input (green, right). The numerical
values are simply typed into the cells using the key to move from
cell to cell. Columns showing the "n/r" label are left blank. Figure 4.7 Bearing units.
The primary unit for horizontal angle is degrees, using the scientific convention in which
zero degrees is to the east and the angle increases in the counterclockwise sense, thus north is 90deg.
Clicking on the abbreviation "deg" in the Hor angle column reveals four options for angular units:
deg, rad, N-deg, N-rad, corresponding to degrees (scientific), radians (scientific), degrees (bearing,
surveying convention, measured clockwise from the north), and radians (bearing). Selecting the N-
deg unit causes VP to convert to the surveying convention, as shown in Figure 4.7.
The foregoing unit conversion exercise demonstrates the way units are selected in VP. To
continue, return the horizontal angle unit back to its original value and change the effluent flow and
effluent concentration units to MOD and ppm respectively. After entering the appropriate values
from the problem description above the diffuser table should look like the one in Figure 4.8. As far
as the diffuser table is concerned, the "base case" is completely defined.
Diffuser, How, Mixing Zone Inputs
Port
elevation
Vertical
angle
Hoi
angle
Numc
ports
n/i
n/i
Acute
IM zone
Chronic
ruin zone
Port
depth
Effluent
flow
Effluent
salinity!*]
Effluent
temp
deg N-deg
Effluent
cone
ppm
20
10
49 0.05
25 100|
Figure 4.8 Completed diffuser table with user-specified units MOD and ppm.
4.11
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Documenting the project
It is usually a good idea to write meaningful notes in the project memo edit box found in the
upper left quadrant of the diffuser tab. Figure 4.9 shows an example.
The ambient table
The ambient table requires only one change of units in the concentration column (to ppm),
to be compatible with the diffuser table. The completed table is given in Figure 4.10. Note that two
depths must be specified even though the second row contains no information except an arbitrary
depth. The second row is prepared as soon as one
tabs past the last column in the table. The
extrapolation parameters indicate that the
ambient values are constant in the water column.
However, even if the extrapolation parameters
were changed by clicking on them, the fact that
Project C:\Plumes\One port
there is only one row data would be interpreted
by VP to indicate that the ambient values are
constant.
Project "C:\Plumes\One port" memoj
A single port, ocean discharge
no ambient stratification
UM3 was specified as the initial model
units on concentration changed to ppm and flow to MGD
Compatible models: UM3, DKHW, Brooks far-field solution
Incompatible models: PCS is for surface discharges,
KRPIELD requires at least 4 ports
Figure 4.9 Project notes.
jtion
Ambient Inputs
Depth or Height
Extrapolation (sfc)
Extrapolation (btm)
Measurement unit
Measurement
depth or height
m
Current
speed
depth
constant
constant
m/s
Current
direction
depth
constant
constant
deg
Ambient
salinity
depth
constant
constant
psu
Ambient
temperature
depth
constant
constant
C
Background
concentration
depth
constant
constant
B^H
Pollutant
decay ratef)
depth
constant
constant
s-1
n/r
depth
constant
constant
m/s
n/r
depth
constant
constant
deg
Far-field
diffusion coeff
depth
constant
constant
rn0.67/s2
1
Ambient file list
Filename
One-Port.001.db11
"
0.1
JO
90
33
0.0003
Figure 4.10 The completed ambient table for the one-port project.
4.12
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The arbitrary depth of 50m could have been set to any other value, however, a depth greater
than or equal to the port depth is strongly recommended to force VP to extrapolate to that depth
(when extrapolation for one or more columns is on). Also, the ambient values could have been input
on the second line, leaving the first line blank except for the surface depth (which does not have to
be zero).
Running the models
An initial analysis is ready to be performed. A click on the model logo will cause the target
model UM3 to be run. Alternatively, the AU ( key sequence) short cut may be used to start
UM3. Finally, it may be selected from the Models menu. The four-panel graphical output is shown
in Figure 4.11 after the Scale button to the left of the graphics panel was pushed.
The numerical output on the Text Output tab should look something like that in Figure 4.12.
There is a variety of information given but one prediction that might be extracted from the text
output is that the predicted dilution at the acute mixing zone boundary is 785.5 to one. If the
corresponding pollutant concentration of 0.124ppm easily satisfies all applicable water quality
Help
Clear al
Plume Elevation
Clear 2a
10
15
?20|
5 30
35-
40
Clear 2b 45
50
Clear 1aj
Clear 1b|
Style-
P 4-pl
<~ diln
10 20 30 40 50 60 70 80 90 100
Horiz. Distance from Source (m)
cus ifjrj
Plan View
I
Scale!
To File
80
60
40
| 20
1 0
1 -20
ift
-40
-80-
-200 -150 -100 -50 0 50
West-East (m)
100 150 200 250
0
5
10
15
I20
01
°30-
33
40
45-
Ambient Properties
50
Jl
—.t
• P
• P
8 10 12 14 16 18 20 22 24
Density (sigma-T)
Plumes Dilution Prediction
10
20 30 40 50 60 70 80 90 100
Horiz. Distance from Source (m)
Figure 4.11 First graphic adjusted by pressing the Scale button on the Graphical Output tab.
4.13
-------
criteria, the analysis might be done.
It is worth noting that the max dilution reached message is triggered by the fact that the value
in theMaximum dilution reported edit box on the Special Settings tab is set by default to 10000. As
soon as UM3 predicts a higher dilution the run is terminated. In reality, a truly buoyant plume, one
that is not subject to nascent density effects, will rise to the surface. This can be done by setting a
higher dilution limit, say 100000. The effect of this change is explored below.
/ Windows UM3. 11/14/00 10:24:27 AM
Case 1; ambient file C:\Pluies\One port.001.db; Diffuser table record
P-dia P-elev V-angle H-angle Ports AcuteMZ ChrncMZ P-depth Ttl-
(i) (i) (deg) (deg) () (i) (i) (i) (M<
0.05 1.0 20.0 90.0 1.0 10.0 100.0 49.0 0
Froude number : 9.62
Depth Amb-cur P-dia Polutnt Dilutn x-posn y-posn
Step (i) (i/s) (m) (ppi) () (m) (i)
0 49.0 0.1 0.05 100.0 1.0 0.0 0.0;
100 48.75 0.1 0.276 13.8 7.077 0.0 0.596;
200 47.94 0.1 1.026 1.905 51.11 0.0 2.032;
300
338
400
467
46
44
41
35
.14
.92
.72
.26
0.1
0.1
0.1
0.1
3.08
4.558
8.538
16.69
0.263
0.124
0.0363
0.00963
370
785
2681
10104
1
5
2
9
0.0
0.0
0.0
0.0
1 .
J. .
£lo Eff-sal Teip Polutnt
3D) (psu) (C) (ppi)
.05 0.0 25.0 100.0
6.212;
10
23
60
.05;
.27;
.45;
acute zone.
lax dilution reached.
10:24:27 AM. aib fills: 2
Figure 4.12 Initial UM3 prediction displayed on the Text Output tab.
What happens when things go wrong?
The last thing the Visual Plumes programmers want to happen is for things to go wrong. But,
the reality is that it is difficult to build a large application like VP without inadvertently
programming bugs. Some problems are system specific and are virtually impossible to anticipate.
Annoying problems may be reported. In an email communication to the email address given above
it is usually helpful to attach the input files with which the problem is associated.
A common problem with programs that shuttle information between files, like changing
projects, is proper re-initialization of all variables. Before giving up on a problem totally, it
sometimes works to simply exit and restart VP. Moving between tabs may also be helpful. A known
bug in VP results in the Style radio group indicating one style of graphics while VP actually displays
another. Pushing a different radio button helps to synchronize these two components.
4.2.4 Modifying the project
Among the most common changes made to VP output are adding variables to the text output
and customizing the graphics.
Adding and removing output table variables
Due to the fact that both effluent and current are directed northward, this problem is a two-
dimensional problem in the y-z plane (in VP the x-axis points towards the east). This is the reason
4.14
-------
why all values in the x-posn column in Figure 4.12 are 0.0. For this project the x-axis position of the
plume element is uneventful and it may as well be removed from the output table. This may
accomplished by clicking on the Selection List pull-down list on the Special Settings tab, Figure
4.13, and finding and clicking the x-posn selection. The selection is removed from the Selected
Variables list. In the same way the centerline dilution (CL-diln) might be added to the list.
Far-field variables
The plume in the simulation listed in Figure 4.12 is
halted prematurely by the maximum dilution criterion,
consequently, the chronic mixing zone is never reached. In
anticipation of running the simulation into the far field, and,
due to the fact that the outfall is to the open ocean, this is a
good time to add the 4/3Eddy variable to the output list. If this
variable is not added to the list the more conservative constant
eddy-diffusivity approach is assumed to apply.
To obtain far-field output the Brooks far-field solution
option must be checked on the Model Configuration radio
panel. Doing so changes the remaining column headers on the
ambient tab from "n/r" to Far-field current speed andFar-field
current direction). As it takes a relatively short amount of time
(about lOOOsec) for the plume element to move from source to
chronic mixing zone boundary, the current is assumed to be
uniform. To be conservative, a diffusion coefficient of 0.0003
may be assumed. Making these changes (inputting 0.1, 90, and
0.0003 in the last three columns) and rerunning UM3 yields the
text output shown in Figure 4.14.
A discussion of the far-field diffusion coefficient is
presented in Figure 4.5.
Analyzing the revised output
Selection List
Selected Variables
Itpul
rn di
Lltpl.
nda
1
Jj
Incnnnt _±
AcuteMZ
ChrncMZ
P-depth
Tti-flo
Eff-sal
Ternp
Polutnt
Bottom
4/3Eddy
Density
Amb-den
Pj
-speed
Dilutn
CL-diln
3^^^^^^^^|
y-posn
Build-up
Time
ExtraVar f
Arnb-cur
P-dia
Polutnt
Dilutn
x-posn
y-posn
0
000
;iose panel
Figure 4.13 Adding and
removing variables from the
output table.
The new output reveals some interesting facts. Most importantly, the plume element reaches
the chronic mixing zone before it hits the surface, consequently, even though the Brooks far-field
algorithm has been linked in, it is never used. For the same reason, the values in the Polutnt and
4/3Eddy columns are identical, suggesting that the former variable could have been removed from
the output table.
4.15
-------
/ Windows UM3. 11/14/00 12:14:32 PM
Case 1; ambient file C:\Pluies\One port.001.db; Diffuser table record 1:
P-dia P-elev V-angle H-angle Ports AcuteMZ ChrncMZ P-depth Ttl-flo Eff-sal
(i) (i) (deg) (deg) ()
0
.05 1
Froude number:
Step
0
100
200
300
338
400
500
502
549
Aib-cur
(m/s)
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
.0 20.
9.
P-dia
(i)
0.05
0.276
1.026
3.08
4.558
8.538
23.18
23.64
37.71
0 90.0
62
Polutnt
(ppm)
100.0
13.8
1.905
0.263
0.124
0.0363
0.00501
0.00482
0.0019
1.0
4/3Eddy
(ppi)
100.0
13.8
1.905
0.263
0.124
0.0363
0.00501
0.00482
0.0019
(i)
10.0
Dilutn
0
1.0
7.077
51.11
370.1
785.5
2681.2
19423.9
20208.6
51255.9
(m)
100.0
CL-diln
0
1.0
3.027
17. G5
108.1
220.2
721.7
5078.3
5281.7
13314.6
(i) C
49.0
y-posn
(m)
0.0
0.596
2.032
6.212
10.05
23.27
97.68
100.6
200.5
(MGD)
0.05
(psu)
0.0
Temp Polutnt
(C) (ppm)
25.0 100.0
acute zone,
chronic zone,
surface.
Outside chronic zone
Figure 4.14 Text output with plume hitting the surface.
Another interesting comparison is between the Dilutn and Cl-diln columns (the dilution and
centerline dilution columns). The centerline is substantially less diluted than is the plume element
on the average. However, the average dilution, as it is associated with the total mass of the plume
element, is a primary UM3 variable. The centerline dilution is estimated based on assumed
concentration and velocity profiles. This relationship can be summarized by a peak-to-mean ratio
between average and centerline values. These dilutions are graphed in the lower right-hand panel
of Figure 4.11. Peak-to-mean ratios are still the subject of research in the plume modeling
community (Frick et al., 2000).
Far-field output revisited
For the sake of this demonstration, let it be assumed that there is a second pollutant that is
discharged at 200ppm and subject to acute and chronic mixing zone boundaries of 50 and 500m
respectively. A new proj ect could be started or the changes could be treated as a separate case. If the
latter, it is only necessary to make a second row on the diffuser table and to input the new values in
the respective columns, as shown if Figure 4.15. Before running the second case press the clear
buttons on the text and graphics tabs. Also, be sure that the row-marker triangle appears to the left
Diffuser, flow, Mixing Zone Inputs
Port nA
diarnetei
Port
elevation
Vertical
angle angle
Her
Nurnoi
ports
f
n/r
nA
til
nA
Acute
mix zone
Chionic
mix zone
Port
depth
Effluent
flow
Effluent
salinity!']
Effluent
temp
Effluent
cone
m
deg
psu
0.05
Figure 4.15 Two concentrations, two sets of mixing zones, two cases.
1
4J
yu
i
1U
50
in
500
v
U.UJ
u
a
1UU
'200
4.16
-------
of the second line of data. If not, move the cursor out of the row, click somewhere, and click on the
row a second time.
The output for Case 2 is shown in Figure 4.16. (Notice that Case 2 is associated with row 2
in Figure 4.15, but in Figure 4.16 it is labeled Case 1. When a new run sequence is started, by
running a model, VP always resets the label to Case 1.) Due to the fact that the chronic mixing zone
boundary is now outside of the initial dilution zone, the Brooks far-field algorithm output is
appended to the former output. The dilution at the chronic mixing zone boundary is almost 65000
to one. This is characteristic of plumes in deep water where there is nothing to stop a plume from
rising and achieving it maximum dilution potential.
The far-field interval in Figure 4.16 implies that the Far field increment (m) edit box was set
to 50m on the Special settings tab.
/ Windows UM3. 11/14/00 1:02:47 PM
i~ci.se 1 ~ ambient +• -• i = f~~ • v ID i -11™=.=^ i"i« =
P-dia P-elev
(m) (m)
0 . 05 1
Froude number :
Amb— cur
Step (m/s)
0 0.1
100 0 . 1
200 0.1
300 0 . 1
400 0 . 1
454 0.1
500 0 . 1
549 0.1
4/3 Power Law .
. 0
V— angle H— angle
(deg)
20 . 0
9 . 62
(deg)
90 . 0
Ports AcuteMZ ChrncMZ P-depth Ttl-flo Eff-sal Temp Polutnt
(5
1 . 0
P-dia Polutnt 4/3Eddy
cone dilutn
( ppm )
2.08E-5 51367
1.39E-6 52843
4.95E-7 55515
2.68E-7 58606
1.74E-7 61798
1.25E-7 64966
. 2
. 0
.4
. 1
.5
.0
(m)
0 . 05
0 . 276
1 . 026
3 . 08
8 . 538
14 . 66
23.18
37 . 71
Farf ield
width
(m)
43 . 85
50 . 35
57 . 14
64 . 21
71 . 55
79 . 15
( ppm )
200.0
27 . 61
3 .811
0 . 526
0 . 0726
0 .0249
0 . 01
0 .0038
dispersion
distnce
Cm)
250 . 0
300 . 0
350.0
400 . 0
450.0
SOO.O
( ppm ^
200.0
27 . 61
3.811
0 . 526
0 . 0726
0.0249
0 . 01
0.0038
based
time
C hrs )
0 . 138
0 . 276
0.415
0 . 554
0.693
0 . 832
(m)
50 . 0
Dilutn
()
1 . 0
7 . 077
51 . 11
370 . 1
2681 . 2
7811 . 4
19423 . 9
51255 . 9
on wastef
(ppm)
0 . 0
0 . 0
0 . 0
0 . 0
0 . 0
0 . 0
(m)
500 . 0
CL-diln
( )
1.0
3 . 027
17.85
108 . 1
721 . 7
2062.4
5078 . 3
13314.6
Cm) (MGD) (psu) (C) (ppm)
49 . 0 0.05 0.0 25 . 0 200 . 0
y— posn
Cm)
0.0;
0 . 596;
2.032;
6 . 212 :
23 . 27;
50.1; acute zone.
97 . 68;
200.5; surface.
ield width of 37.71 m
Cs-1)
0 . 0
0 . 0
0.0
0 . 0
0.0
0.0
Cm/s) (mO . 67/s2)
0.1 3.00E-4
0.1 3.00E-4
0.1 3.00E-4
0.1 3.00E-4
0.1 3.00E-4
0.1 3.00E-4
Figure 4.16 Case 2 with far-field output
Customizing graphics
A crude way to customize the graphics, or, to make the plots fit the graphics panels, is to use
the Scale button on the Graphical Output tab. For single runs this often frames the graphics well,
however, the scaling algorithm does not work as well when multiple plots must be scaled.
The graphic panels may be customized individually by double-clicking in the margins of
each graphic (outside the plot area). Figure 4.17 shows one of the Graphics control windows, for
the four-panel dilution graph, that can be accessed in this way. This control is set to customize the
horizontal axis. The values next to the Minimum and Maximum edit boxes are extreme values
encountered during the plotting process. They serve as guides for framing the graphic but are not
reliable indicators when many runs are graphed.
4.17
-------
It is important to refer to the Auto Scale
check box. If it is checked the inputted minimum
and maximum values will not be accepted. To
manually change the settings, the Auto Scale check
box should not be checked. Visual Plumes always
attempts to reset Auto Scale to off at the beginning
of each project.
While for finished products the graphics
may be highly customized, the VP list files only
store selected settings, for example, minimum,
maximum, and increment for each coordinate axis,
and, legend on or off. Consequently, such
customized graphics should be saved in some
manner before exiting the project. The To File
button may be used to create bitmap files of the
graphics panels. The bitmap files are each over two
megabytes and should be converted to more
compact formats or deleted from the directories
Graphics control
General Horizontal Axis Vertical Axis 1 Legend) Series I
Minimum
Maximum
Increment
Auto Scale
Grid Lines
Axis Title
1600.00
(0.00)
(500.00)
None T Solid (? Dotted
Horiz. Distance from Source (m)
OK
Cancel
promptly. A customized version of the graphical Figure 4.17 Graphics control for the four-
output is shown in Figure 4.18. Panel dilution graph frame.
Ambient Properties
5
10
15
ga.
62i
S30
35'
«.
43
y
•
*
/
'
•
7
'
/
,
]
]
|
|
|
]
!
!
!
!
— Plume profile
- Plume Profile
+ Pfume Bndry
+ Plume Bndry
0 50 100 150 200 250 300 350 400 450 500 550 600
Horiz. Distance from Source (m)
600
550
500
450
^400
E
^350
z300
^250
"200
150
100
50
0
Plan View
'
•
•m
'
!
v
\
J
X
•
/
.
- Piume path
— Plume path
• Outline
* Outline
-40 -30 -20-10 0 10 20 30 40 50
West-East (m)
5-
10-
15-
I"
f 2S
°30-
35
40
45
•
I
!
;
i i
i i
• S
J
-.""V"»"v-ri-«-y -
24.1 24.2 24.3 24.4 24.5
Density (sigma-T)
80,(
70,(
o"0,<
XV
140,1
iD
30,
aw
10,
- Amb. density
- Amb. density
• Plume density
* Plume density
Plumes Dilution Prediction
00 •
m:_
00
00
00 \
00-
/
/
~/^-<^
/
/
/
^^
/
/
1
/
/
- Centerline
- Average
- Centerline
- Average
0 50 100 150 200 250 300 350 400 450 500 550 600
Horii. Distance from Source (m)
Figure 4.18 Customized graphics output.
4.18
-------
4.2.5 Adding another ambient scenario
The example above shows the great dilution potential of plumes discharged to deep,
unstratified receiving water. This modification to the proj ect illustrates the profound effect of density
stratification on dilution while providing an opportunity to develop multiple ambient scenarios.
Creating a second ambient input file and table
To start this exercise it is important that the ambient tab is the active tab. Click on the File
menu and select Save ambient file as command. (The Add existing ambient file command is reserved
for adding existing files and cannot be used to create new ambient files. If the ambient tab is not the
active tab, VP will assume that an entirely new project is to be created. One should make sure that
the File menu option is not File project as.)
Once the Save ambient file as command is issued the Save as dialogue window should appear
with the default filename Oneport.002.db. This ambient filename can be changed to any filename
consistent with the ambient file naming convention, however, if the default name is accepted it
establishes a sequence of names that is easily manipulated in the Ambient file list on the diffuser tab.
The disadvantage is that one would have to remember what ambient scenario is stored in what could
be project having many ambient files.
For the purposes of this tutorial, the default name is accepted. VP then adds the new file to
the Ambient file list., closes the previous file One port. 001. db, and puts One port. 002. db on the
ambient tab. Thus, the way the Save ambient file as command works is that it closes the existing
ambient file after making a copy of it and giving the copy a new name.
A density stratified scenario
To add realism to this example and to illustrate some of VP's more general capabilities, a
fairly elaborate ambient scenario is proposed. To get to the input that looks like that in Figure 4.19,
the lines could be erased (using the key) and input started over. The following
alternative way affords opportunities to practice editing skills.
First, click on any cell in the first (Om) row of the ambient table and press the key.
This will insert a new first line. Enter a 0 in the first column to establish the row (otherwise it will
disappear if you move off the row). Move to the second row, repeat the procedure and insert another
line and enter a depth of 3m. Now move to the temperature column and enter the value 20C. Next,
move to the first column, third row and change the value to 20m. Move to the 50m row and insert
another row, making its depth 40m and its salinity 33.1. Still in the salinity column, move the cursor
up to the Extrapolation (btm) row and click until it shows extrapolated. Finally, delete the decay rate
value (0) from the third row and re-input it on the first. To delete the value from the cell, click on
it a second time to select only the value and then press the key. The ambient tab should
now look something like Figure 4.19.
4.19
-------
Arr
Depth 01 Height
Extrapolation (sfc)
Extrapolation (btmj
Measurement unit
L
bient file list
:ilenarne
Oneport.001.db11
Oneport.002.db11
I
Measurement
depth or height
m
Current
speed
H9HI
constant
extrapolated
m/s
0
3
20
«
50
0.1
Current
direction
Ambient
salinityf")
Ambient
temperature
depth depth depth
constant constant constant
constant extrapolated constant
deg psu |c
90
33
33.1
20
15
Background
concentration
depth
constant
constant
ppm
100
Pollutant
decay ratef1]
depth
constant
constant
7-\
0
Far-field
current speed
depth
constant
constant
rn/s
0:1
Far-field
current direct
depth
constant
constant
d^
90
Far-field
diffusion coeff
depth
constant
constant
m0.67/s2
0.0003
Figure 4.19 The density-stratified scenario: Oneport.002.db.
This ambient table emphasizes that not all cells need to be filled, in fact, an important
attribute of VP is to avoid redundant input. This is not so much a convenience to the user as it is a
way to be able to examine the table to gain an appreciation for the data that are available and to
make comparisons with similar tables easier.
Before continuing, if desired, any text and graphics that have accumulated might be cleared.
One way to clear the board is to exit and restarting VP; if that path is chosen the new scenario can
be re-established by clicking on the One port. 002.db filename in either Ambient file list. Once again,
VP is able to recover the changes from a previous session from the project's List file, but, fine
changes to the graphics panels (like customized labels and titles) are not currently stored for future
reference.
CAUTION: It is a good idea to check the name of the ambient input file recorded at the top
of the text output for each run to assure the right ambient input is being used.
To appreciate the effect that the new input and extrapolation setting have on the output, go
to the Special Settings tab and add the ambient salinity (Amb-sal) and temperature (Amb-tem) to the
Selected Variables list. This will cause these variables to be output variables and will show how they
change as the plume element rises through the water column.
Customized graphics
One of the graphics styles available is the custom graph accessed by clicking the cus radio
button on the Style cluster on the Graphical Output tab. The abscissa (x-axis) and ordinate (y-axis)
of graph panel can be specified on the Graphics settings panel on the Special Settings tab. To set the
variables, push the Abscissa (x) and Ordinate l(y) radio buttons, each time selecting the desired
coordinate variable from the Custom variables pull-down list. In this case time (Time) and pollutant
concentration (Polutnt) are selected for plotting. The time is the time required for a given plume to
travel from the port to any point along the plume trajectory. (The second ordinate is not presently
fully implemented).
If the Casecount variable is selected for the x-axis, VP graphs "summary" statistics. For
example, if the corresponding y-axis variable is Poltnt (average pollutant concentration in the
4.20
-------
plume) then the predicted concentration at maximum rise will be plotted for every case in the run.
Maximum rise could be either at some intermediate level in the water column or when the plume
hits the surface.
Comparing models and interpreting the results
In the One port project memo it is stated that UM3, DKHW, and the Brooks far-field
algorithm are appropriate for this problem. PDS would not be used with this input because it is a
surface discharge model, and, NRFIELD would not be used because it is an empirical model for line
sources, requiring at least four ports (two T-risers) to be applicable. This example provides an
opportunity to compare the UM3 and DKHW initial dilution models. Some of the model predictions
are shown on the 4-panel graph in Figure 4.20, UM3 output in red (the trajectory with the greater
rise and slightly lower average dilution) and DKHW in blue. Note that the legend for the elevation
view has been turned off on the Special Settings tab.
Plume Elevation
10-
20
'30-
10
20
30 40 50
Horii. Distance from Source (m)
60
70
80
Ambient Properties
23 23.2 23.4 23.6 23.8 24 24.2 24.4 24.6 24.8
Density (sigma-T)
Plan View
-20
-10 0 10
West-East (m)
30
VYesi-c«3L 1/11,1 nurii.
4.20 One port output for the density stratified ambient scenario
10 15 20 25 30 35 40 45
Horii. Distance from Source (m)
50
Figure
From the predictions it is apparent that, compared to the unstratified case in Figure 4.16, the
plumes do not reach the surface and the dilution attained is much smaller. The average dilution is
4.21
-------
less than 5000 compared to over 50000 previously. Even relatively weak stratification has a
profound effect on dilution. Stronger density stratification would further reduce dilution. The solid
lines in the Ambient Properties panel plots the stratification in sigma-T units (for example, 24o T is
equivalent to 1024kg-m3). It can be seen how the plume element changes its buoyancy (compare
point density to ambient density at the same depth) as it rises through the trapping level, the point
at which the average plume density and ambient density are equivalent. As the plume element
possesses upward momentum at this point it passes through this level and becomes negatively
buoyant. The negative buoyancy above the trapping level decelerates the plume element, reducing
the vertical velocity of the element until the vertical velocity reverses and the plume falls back
towards the trapping level.
Under ideal conditions a plume will oscillate about a varying trapping level at the so-called
Brunt-Vaisala frequency as a wave form. Check this by pressing the 1 (to 2nd max rise or fall) radio
button on the UM3 max vertical reversals radio group and rerunning UM3. The simulation passes
through maximum rise and is continued to the next trapping level. Subsequent trapping levels vary
slightly because entrainment continues to change the average density of the element.
Extrapolation
In setting up the ambient table in Figure 4.19, the salinity column Extrapolation (btm) cell
was toggled to the extrapolated setting. In Figure 4.20 the effect of this setting is reflected by the
fact that the density continues to increase (is stable) below the 40m depth. Effectively, the density
is extrapolated from the values at the 20 and 40m levels. On the other hand, shallower than 3m the
density is constant because surface extrapolation is not specified.
Zooming graphics
Ambient Properties
37-
Any of the graphics can be dynamically
zoomed. Using the mouse, click and drag an
imaginary box, corresponding to the rectangular
area which is to be included, from upper left to
lower right. A "rubber-band" box will appear that
shows the zoom area. Upon releasing the mouse
button the graph is re-scaled. The initial scale can
be restored by creating a box in the opposite
sense, in other words, by starting from the lower
right-hand corner and releasing the mouse button
at any upper left-hand corner. Figure 4.21 shows
the results of a dynamic zoom on the Ambient
Properties panel. Magnified in this way, the Figure 4.21 Density modeling details.
predicted depths of the trapping levels can be
read more easily, varying from about 42m for UM3 to about 44m for DKHW.
24.75
24.8
24.85 24.9 24.95
Density (sigma-T)
25.05
4.22
-------
The peak-to-mean ratio
Another significant difference in the predictions is of the centerline dilution (Plumes Dilution
Prediction panel in Figure 4.20). While the average dilutions compare favorably, the centerline
dilutions differ by about a factor of two. As both models are fundamentally predicting average
dilutions, the reason for the difference is in the way the centerline dilutions is calculated. Both
assume a 3/2-power profile but integrate in a different way to estimate the peak-to-mean ratio
between centerline and average plume concentrations. The results are shown.
Recent experiments by Roberts (2000) suggest that the peak-to-mean ratio calculated by
UM3 may be substantially too high. This problem is likely to be the focus of future research.
Custom graphics
The custom graphic set up in the Customized graphics section above is given in Figure 4.22.
The rapid decay of pollutant concentration due to entrainment as a function of time is apparent.
Predicted Relationships
10 11 12 13 14 15 16 17 18 19 20
Figure 4.22 Custom graphic showing pollutant concentration plotted
versus time.
Tips to remember
When the Case selection Base or selected case radio button is selected, it is important to
remember to click on the desired row, or case, before running the models. The case-indicator
triangle (») should be pointing to the appropriate case before running the models. The correct Case
4.23
-------
Number should show in the Parameters for selected row panel in the lower left quadrant of the
diffuser tab. Similarly, when multiple ambient files are displayed in the Ambient file list, be sure to
select the desired ambient file (or scenario) before running the models. The correct filename should
be displayed on the protruding tab at the top of the ambient tab.
On the ambient tab, if any extrapolations are indicated, as they are for salinity in the One
port.002.db file, then a 0 depth and a depth below the depth of the discharge port should be
specified. This will assure that any ambient pairs of data are properly extrapolated and that the
density profile is plotted fully on the Ambient Properties graphics panel.
Partnership with the user
If one simply reads this tutorial, the One-port example may appear to have been developed
quickly and smoothly. In reality, the act of creating the tutorial encountered difficulties that were
generally overcome by drawing on experience, but, in a couple of instances minor bugs were
revealed that had to be resolved. Not to resolve them would risk adding to the frustration and
annoyance that the user may feel when things do not work as advertised or the procedure is not
intuitive.
There is no question in the minds of the authors that, as
N urn of
ports
Port
spacing
n/r
m
with its predecessor, Visual Plumes will give the best results if IJiiiuser,
its application is partnership between the developers and users, r
The user does not share the experience of the developers, but, 3Je_
the reverse is true also. Until models are perfect, and this 3
development project shows that this one is far from that, the 901
best that can be hoped for is that there exist a partnership
between developers and users that will draw on the talents of
both to make an imperfect tool serve the needs of the user. Fi§ure 4'23 Multi-port diffuser.
4.3 Multi-port discharge
Specifying multi-port diffusers
The single-port example above can easily be changed to a multi-port example by specifying
more than one port in the Num of ports column of the diffuser tab, Figure 4.23. Once so specified,
the Port spacing label appears in the column to the right of the Num of ports column and a value
must now be specified. A two-port diffuser, as shown, would have significant end effects and would
represent a conservative analysis.
Some assumptions
The assumptions for multi-port plume prediction vary somewhat with model. The UM3
model treats multi-port plume prediction the same as single-port plume prediction up to the point
merging. One important assumption is that all plumes in a given linear diffuser, with the exception
4.24
-------
of orientation, are identical. In contrast, the NRFIELD (RSB) model is based on the assumption that
multi-port plumes can often be assumed to be emitted from line sources.
With all three VP models it is assumed that the ports point perpendicular to the axis of the
diffuser, therefore, staged diffusers, which have ports pointing at an acute angle to the diffuser, can
only be modeled by making additional assumptions.
Merging
Merging theory is covered in some detail in Baumgartner, Frick, and Roberts (1994). UM3
uses the concepts of effective spacing and reflection from a plane to help estimate the effects of
merging. Effective spacing is an estimate of the true spacing between plumes at any point. With the
generalization of UM3 to three dimensions, additional assumptions regarding the merging of plumes
are made. Most importantly, when the angle between the current and the instantaneous plume
element direction is less than 20deg, the effective spacing is no longer trigonometrically reduced.
An important simplification involving cross-diffuser merging
Diffusers with ports on both sides of the diffuser pipe discharge plumes into opposite
directions, creating co-flowing and counter-flowing plumes. Counter-flowing plumes are discharged
up-current and will generally rise and bend back into the direction from whence they came,
eventually merging with the co-flowing plumes that are discharged on the opposite side of the pipe
in direction of the current. This is called cross-diffuser merging.
One way to model cross-diffuser merging is to model the counter-flowing plumes first and
to use the output from them to establish background conditions, especially pollutant concentrations,
for subsequent co-flowing plume runs. This can be a tedious undertaking.
An alternative approach, that represents a major simplification and that appears to be fairly
accurate based on the results of informal modeling trials, is to treat the diffuser as if all ports are on
one side with half the spacing. In the context of merging plumes, this approach works well when the
distances of interest are somewhat beyond the point of merging. Thus, there is only a limited range
of distances, beyond the point of merging and this point where the assumption is unimportant, where
the modeling results will suffer some level of uncertainty.
4.25
-------
4.26
-------
5 Advanced Considerations
5.1 Time Related Data, Time-Series Files
The value of time-series files
For maj or diffusers or special studies, there may be a need for detailed analyses to adequately
describe performance under a range of conditions. In such cases, it is often useful to run the plume
models with measurement data taken specifically to predict the likely performance of the outfall
under a range of conditions actually recorded during a monitoring study. VP addresses this need by
allowing the use of time-series input from files, such as from monitoring reports, in lieu of data
specified in the input tables.
Once data are formatted in the prescribed fashion including the information echoed under
the time-series filename row of eligible variables, viz.,Port depth, Effluent flow, etc. on the diffuser
table, and Current speed, Current direction, etc., on the ambient table, VP can read the time-series
files in place of the input table and provide the corresponding prediction and output. In this way, VP
can analyze literally thousands of cases in a systematic fashion. The additional time and effort
(which depends on the amount of data manipulation required to get the time-series into VP
compatible format) may then be recovered from not having to create the numerous ambient input
files that would otherwise be required.
VP can cycle through the time-series files repeatedly to simulate initial and far-field dilution.
For example, a time-series effluent flow file that records only the diurnal cycle of a wastewater
treatment plant may be combined with a very long current meter file thousands of records long.
When VP reaches the end of the short effluent flow file it will simply reset it and read it again, as
many times as necessary. In addition, VP will synchronize time-series files of unequal time
increments. Each file must be set up to start at the same time (time "zero") even though the user has
control over when the simulation begins through the Start time column on the Diffuser tab. The
ending time and time increment determine how many cases are analyzed.
A tutorial gives a complete time-series analysis example to help illustrate the main points
of this capability.
Linking time-series files
The Diffuser and Ambient tabs both can accommodate time-series files. The linkage is
accomplished in the Time-series files (optional) panels, Figure 5.1, after the time-series files are
created, as is explained subsequently. Given the associated files exist, they may be linked in by
clicking on the cell that displays the click for file prompt in the appropriate column. When this
prompt is visible it indicates that no file is presently linked to this column, the default configuration.
However, the replacement of the prompt by a filename is not a guarantee that the corresponding file
is linked in if the file is not in the indicated directory. Clicking a file off and re-linking it will
establish whether or not the time-series file is actually available.
5.1
-------
Given that "TS series.vpp.db" is the name of the project file listed on the Diffuser tab, the
default name for the "borrow project" will be the same and will appear in the edit box after the
Borrow time-series from project label. If another project is to be referenced, it can be made the
borrow project by clicking the Borrow time-series from project edit box to pop-up a directory
dialogue. Once the correct references are established and the file "TS series.vpp.flo" exists, a click
on the click for file cell in the Effluent flow column will open the time-series file.
Preparing diffuser table time-series files
Time-series files must be created external to VP using an appropriate ASCII text editor
(which can be a word processor that can save files in ASCII format). Each time-series file is headed
by a line of information that allows the data in the file to be properly interpreted, followed by a
Time Series-Files (optional)
Borrow time-series from project: |CAPIumes\Ketchikan.vpp.db
Port
depth
Effluent
flow 1
Effluent
salinity^)
Effluent
temp
Effluent
cone
click for file
Figure 5.1 Window for linking effluent (diffuser table) time-series files to Visual Plumes.
listing of the data. Given a project name of "TS series", the following data is an example of an
effluent flow time-series file:
1.05MGDTS series.flo
2
3.2
5
4.5
3.5
The first line is interpreted to mean that the time-series increment is 1.0 hour, there are five
periods, and the unit of the values in the file is MGD. When it is clicked, the filename replaces the
click for file prompt and the time-series increment and period values are displayed in the cells
immediately below the filename. The name of the file on the header line in the sample file above is
not required, read, or used by VP. It's presence is recommended for documentation purposes.
The data above are flows at hour zero (2MGD), hour zero plus one (3.2MGD), hour zero plus
two (5MGD), through hour five (3.5MGD). If hour zero corresponds to midnight, the data would
represent flows from midnight to one, one to two, etc.. If more than five hours were simulated, the
data would be repeated, five to six a.m. would be 2MGD, etc.. The value in the Start time column
will determine whether the first datum used is 2, 3.2, 5, or some other value.
CAUTION. Upon linking a time-series file, i.e., upon clicking on the click for file prompt,
VP clears existing data in the corresponding column of the diffuser table, here the Effluent flow
column, because it is superseded by the time-series file data. If there is important data in this column
5.2
-------
pertinent to another part of the study, it might be best to create another project before linking in
time-series files.
Time-series file extensions
The file extensions for the time-series (tan) flow variables are:
dep: port depth,
flo: effluent flow
sal: effluent salinity
tern: effluent temperature
pol: effluent pollutant.
Ambient Time-Series Files
The ambient time-series files are more complicated because the information is not scalar by
nature. A time-series effluent flow variable (one of those under the tan headers on the diffuser tab)
is described by a single number at each measurement time. Ambient data, on the other hand, are only
represented by a single value if the ambient property is constant with depth. The ambient variables
may require multiple inputs for each measurement time, corresponding to the available depths at
which measurements are recorded. Consequently, the ambient time-series file header array contains
additional information defining the depths of the subsequent columns of numbers. For example,
consider the time-series input file "TS series.001.spd" for current speed:
1.00 6.00 m/s 0.0 constant extra m 10 15 20 25 30 TS series.001.spd
0.150.160.160.160.20
0.150.160.170.180.19
0.140.130.120.11 0.10
0.100.200.300.400.50
0.20 0.20 0.20 0.20 0.20
0.21 0.21 0.220.230.24
As before, the header line provides information on measurement units, depths, and other
pertinent parameters. The values of the first line have the following meanings:
1.00 time increments (hr),
6.00 Total period (hr),
m/s units of measurement (m/s).
0.0 depth or height (depth = 0.0; height would be indicated by a positive value defining
the distance between the port and the surface),
constant surface extrapolation information (constant in this case, other options are
extra(polated) or lin(ear-to-zero)
extra bottom extrapolation information (same options as above)
m the units of the depths at which the measurements were made (m),
5.3
-------
10... the depths (10, 15, 20, 25 and 30m in the example; must correspond to the number
of columns),
TS series... the file name (the filename and other appended text is optional).
Both time increments and total period must be expressed in hours.
Following the header line is a matrix of currents with rows representing consecutive evenly
spaced times and columns representing the different depths. For example, the current during the
sixth hour at 25 meters depth is 0.23 m/s. See the previous section for a discussion of the time
convention.
A detailed discussion of depth and height is given in the following section. Briefly, if
measurements are recorded depth-wise a value of 0.0 is indicated after m/s in the header line. If
measurements are recorded height-wise, the height of the measurement datum (for example, Mean
Lower Low Water, or MLLW) above port depth will be entered.
The file extensions are:
spd: ambient current
dir: ambient current direction relative to the x-coordinate
sal: ambient salinity
tern: ambient temperature
pol: ambient pollutant concentration
rat: ambient pollutant decay rate (or solar insolation)
far: ambient far-field current
dis: the ambient far-field dispersion coefficient.
When an ambient time-series file is linked to VP the corresponding column in the ambient
table receives the depths in the time-series file: 10, 15, 20, 25, and 30m. This information is used
by VP to interpolate and extrapolate the times series data. Caution as with the diffuser table, any
existing values in the column are overwritten. When a time-series file is linked in, the values in the
corresponding column in the ambient table are depths and the unit of the column will be a depth unit.
5.2 Depth vs. Height
CAUTION: This section describing the height mode describes capabilities of VP that exist
but have not been independently tested.
5.4
-------
Ditfusar Anchor
Weight
Instrument
Float
or Buoy
Figure 5.2 Two measurement configurations comparing height and depth-based measurement
scenarios.
The Diffuser tab allows for a Port depth time-series input file. This is to accommodate
variable water body depth arising from river stage variations, reservoir and lakes levels, or tides.
Variable water-column depths pose programming problems when data are used that were collected
from an instrument platform moored to the bottom, because its depth will vary with time. This
problem, illustrated in Figure 5.2, can be overcome by allowing for both depth-based and
height-based ambient time-series input files.
Figure 5.2 depicts a diffuser running perpendicular to the plane of the paper with current
from left to right. A variable tidal surface is shown, which could just as well be a changing stage of
river flow or surface elevation of a reservoir. Two measurement strategies are depicted, one in which
an instrument is suspended from a buoy and a second one in which instruments are moored to the
bottom, the mooring held more or less vertical by a float.
It should be apparent that in the buoyed case the depth of the instrument stays constant even
as the depth of the water column changes. In the moored case, however, the depth of the instrument
is variable, depending on the water column depth. In order to maintain a level of simplicity in
programming, VP uses the same algorithm to interpolate both depth and height based ambient data.
For this to work, certain rules for creating height based input files must be observed. For example,
given the current speed file TSseries. OOl.spd, recorded on the header line of the ambient time-series
file, the value of 0.0 following the file units of m/s must be replaced by the height of water above
port depth corresponding to the appropriate datum, such as MLLW or Mean Water Level (MWL).
5.5
-------
In the Sand Island example in a following tutorial, it might be 69.8m. One could also think of this
to be the depth to port level measured from the water datum.
An ambient file similar to the depth file above but using height and a diffuser at a MLLW
depth of 33 m, might be as follows (changed parameters in italics):
1.00 6.00 m/s 33.0 constant extra m 23 18 13 8 3 TS series.001.spd
0.150.160.160.160.20
0.150.160.170.180.19
0.140.130.120.11 0.10
0.100.200.300.400.50
0.20 0.20 0.20 0.20 0.20
0.21 0.21 0.220.230.24
Once the height-based ambient data mode is established, VP will take the base case port
depth and use it to compute the corresponding depths at which the height-based data were obtained.
In other words, at run time VP will offset the interpolation depth for height-based ambient
time-series files. In this way the same interpolation algorithm used for depth specific ambient files
can be adapted to height-specific files.
5.6
-------
6 Additional Applications
This section describes several sample problems that demonstrate the use of VP. These
problems are included in the built-in help system as additional tutorials and predate the tutorial given
in Section 4. Some of the material complements the tutorial in Section 4, but some is redundant. An
effort is made to suggest the possibly redundant nature of passages with appropriate headings. For
example, the section below on editing data has been covered to some extent in the tutorial in Section
4. As VP has evolved substantially over its development cycle, in some cases the material may not
reflect the most recent changes and improvements to VP.
The sample problems given here are available with the VP setup CD and are ready to run.
6.1 Oil well problem
The following problem is based on cases where offshore drilling rigs are discharging effluent
as a by-product of the drilling exploration process. The industry wants to run several cases to
determine the effects created by varying the effluent density and flow. The problem provides an
opportunity to compare the single-port models, UM3 and DKHW.
This project is on the Visual Plumes CD as a prepared example (Oil wells.vpp.db), however,
it is described here as if it were developed from scratch. It is up to you whether you want to start
from scratch or not.
Editing data
Some of the fundamentals of editing data are presented in Section 4. The hints here
recapitulate and expand on the topic.
To overwrite a value a existing value, enter the cell and type the new value before doing
anything else. Editing an existing value requires first selecting the cell and pressing to put
the cell in edit mode. The standard editing keys, like or , may then be used to move
about the cell to change or add characters. After first exiting the cell editing mode, for example, by
clicking on another cell, the entire row may be deleted by holding down the key while
pressing the key.
Editing data with popup menus
When the cursor is in the diffuser or ambient tables, a &elete Precedin9lines
right-click of the mouse brings up a popup menu, which includes Delete this and following lines
options for the wholesale deletion of rows of data (Fig. 6.1). Another Font [Ditch
option is Fontpitch. This is a useful option when input values are too Help
large for the boundaries of the cell. However, notice that values can ^ ,
usually be examined in their entirety in the Parameters for selected ~
row list on the Diffuser tab by selecting the cell to be examined. Figure 6A Popup menu'
diffuser and ambient tables.
6.1
-------
Units conversion and the Label only option
The first column in the diffuser table is for the port diameter,
which is 11.75 in. Before entering the value one would change the unit
by clicking on it.
The second column is not required (it is reserved for the
conduit depth used in PDS) but has the units of meters. The fact that
the column is not required may be ignored to illustrate the Label only
-Units Conversion—i
C Convert data
(*" iLabei only
-. V.:
•"-
option. For the sake of practice, without first changing the unit, enter ° P •
a value of 11.75 into this empty cell and then imagine that you filled in an entire column of values
before realizing that the units do not match the data. To change meters to inches without affecting
the inputted values in the column, click the Label only option on the Units Conversion panel (Fig.
6.2). Then click on the units cell in the column with the newly input value and select the in unit. In
response to this command only the unit label changes, as desired.
After the label has been corrected, be sure to return the Units Conversion panel back to the
Convert data mode. When done the test value may be deleted.
Oil well diffuser and effluent input conditions
This is a multi-run problem (effluent flow and effluent temperature vary). The following
values describe the produced water discharges.
Port diameter
Port elevation
Vertical angle
Horizontal angle
Number of ports
Acute mix zone
Chronic mix zone
Port depth
Effluent flow
Effluent salinity
Effluent temperature
Effluent concentration
11.75in
50m
90deg
90deg
1
10m
100m
50m
10000, 6000, 2000bbl/day
31psu
16.46, 38.49, 74.96C
lOOppm
The base case should look like Figure 6.3. Remember, to change the units (flow and
concentration) before entering the rest of the data.
Diffuser, How, Mixing Zone Inputs
Port
diametei
•i
0.29345
n/r
rn
Port
elevation
m
50
Vertical
angle
deg
90
Hoi
angle
deg
90
Numof
potts
1
n/i
m
n/i
s
n/r
s
n/i
s
Acute
rain zone
m
10
Chronic
ruin zone
rn
100
Port
depth
rn
50
Effluent
flow
bbl/d
10000
Effluent
salinity!")
psu
31
Effluent
temp
C
16.46
Effluent
cone
ppm
100
m
Figure 6.3 Oil well project base case for given input conditions.
6.2
-------
Adding other cases
Again, the purpose of the study is to determine the effects of flow rate and densities
(effectively, salinity and temperature) on dilutions. To obtain a permit to build or operate an outfall,
it is necessary to establish limits on flows, if any, that will meet water quality criteria. To determine
the dilution, or concentration, of the different effluent flows at varying densities, the user might set
up various cases representing the range of conditions likely to be encountered. In this problem there
are three effluent flows, each with three different densities, nine cases in all. The two columns that
will need additional input values representing are the effluent flow and density columns, both found
in the green section of the diffuser table.
The easiest way to add these values is to click on the column that requires additional input,
using the down-arrow key to create a new line. The first column chosen is the Effluent temp column
(it could just as well be the Effluent flow column). By changing the temperature of the effluent the
implied density changes as well, salinity held constant. The following values will be input into the
effluent temperature column going from top to bottom: 16.46, 38.489, 74.961, repeated two more
times.
Finally, under the effluent flow column, go down to the fourth line and type in 6000
(bbl/day). VP interprets this to mean that the first three cases have the same flow. Beginning with
the fourth case, it will use all of the input values from the base case except the effluent flow and
temperature. Repeat the procedure on the seventh line, entering 2000. There should be a total of nine
lines in the diffuser table. Clicking on the last line after scrolling the window will show Case 9 in
the Parameters for selected row panel. Don't panic when the base case is no longer visible, it is still
there, however, when moving from row to row, press the Parameters for selected row button to
update the variables in the panel.
Useful parameters
The Parameters for selected row panel shows useful information. The densimetric Froude
number is a key similarity parameter that gives information about the relative importance of
buoyancy and momentum on plume rise. A low value, especially one less than unity indicates the
plume is dominated by buoyancy, a large value, commonly 10 to 100, indicates momentum is
dominant. A value of unity represents conditions near the point at which horizontally discharged
effluents begin to no longer fill the nozzle. The buoyancy is so great that the effluent squeezes
through the upper portion of the orifice leaving space underneath the exiting flow for ambient
inflow. This process can radically alter the performance of the diffuser. Flex valves offer a way to
increase the Froude number.
The panel also reports effluent density and velocity. These are frequently of interest. The
latter is sometimes an indicator of internal diffuser hydraulics. Low pipe velocities can lead to
deposition within the pipe which will then alter the distribution of port velocity in multi-port
diffusers.
As one uses the tab key to move from column to column in the diffuser table, the values in
the panel change. This offers a way to see the value converted into the primary units, if the column's
6.3
-------
unit is something other than the primary unit. This is useful because the base case may be out of
view.
Salinity, temperature, and nascent density
If you wonder where the temperature used in this problem came from, the answer is from
density. In the original problem, neither effluent salinity or temperature were provided. This is a
problem from the viewpoint of the nascent density effect because buoyant brines can become
negatively buoyant as they rise through the water column and entrain ambient water. While the non-
linearities in the equation of state may not be important in some cases, it is always best to specify
both salinity and temperature. Therefore, supposing it is known that temperature is the variable
determinant of density, VP input is based on the presumption that a guess of the value of salinity will
probably lead to better results than using a linear equation of state. (A similar argument holds if
salinity is the variable determinant of density.) The linear equation of state essentially assumes that
the mixing process results in densities that fall on the straight line that can be constructed between
the ambient and effluent densities on a density diagram. This is not generally a good assumption.
This problem is intended to be instructive. No
In this problem the density for the base case was 22.6oT, or 1022.6kgm"3. This is easily
established by clicking on the units (remember to revert to the Convert data option on the Units
Conversion radio group, Figure 6.2). The salinity was not given but it is known that it is in the
neighborhood of 31psu. (It could be 33psu, in which cases the temperatures would need to be
readjusted to produce the desired densities.) To establish the original densities for the other cases,
it would be necessary to first input 31 (psu) in the first three cells in the column to force VP to
convert that cell to a density value. The corresponding densities are 15.6oTand-4.4oT. In converting,
VP may report -4.40004oT for -4.4oT. These conversion errors occur because VP uses a Newton-
Raphson method to solve the highly non-linear equation of state when converting from temperature
to density.
Notice the process of changing salinity units causes the column header to change to density
if a density unit is selected.
Substitute diffuser backup file
If you entered a number of 31psu values in the salinity column to see the conversion to
density, you may now wish to erase them. The normal way to do this would be to erase each cell
individually.
In this case, if you started this problem from the prepared case (i.e., you did not enter all the
input values from scratch), and, you have not otherwise modified the file since it was opened then
VP still has the original backup file for reference. To re-establish the backup file one may use the
Substitute diffuser backup file from the Edit menu.
6.4
-------
Multiple runs
To set VP up for multiple runs, the Sequential, parse ambient case selection radio button in
the Case selection panel should be highlighted. This selection will run the cases from the top to the
bottom on the Diffuser tab, but will only do so with the ambient table indicated on the ambient tab.
(If there were case number ranges after the filename, it would also select the appropriate ambient
files for those cases, after parsing or extracting that information from the filename.) The Model
configuration checklist also should be checked as appropriate. For this problem requiring estimates
at the mixing zone boundary set at 100m, the Brooks far-field solution option should be selected.
The Graph effective dilution option may also be checked. The After run go to radio group options
may checked and changed, for example, to Graphics. The completed diffuser tab should look
something like Figure 6.4.
Project C:\Plumes\Oil weUs
Ambient file list
Filename Case:
Project "C:\Plumes\Oil wells" memo
11.75inports ( = 0.29845rn)
current: 11.5cm/sec
open water dispersion coeff = 0.000462
- After run go to tab
(~ Diffuser
T Ambient
C Special
T Text
(• Graphics
Model Configuration
Units Conver:
Convert data
f Label only
UM3
_ Brooks far-field solution
Graph effective dilution
Average plume boundary
Amb. current vector averaging
Tidal pollution buildup
Same-levels time-series input
- Case selection
(* Ease or selected case
("" Sequential all ambient list
f Sequential, parse ambient
C All combinations
It
l_
Port
diameter
Hi
11.75
InA
m
Port
elevation
m
50
Vertical
angle
deg
90
Hor
angle
deg
90
Numof
ports
1
nA
m
n/r
min
nA
hr
nA
hr
Acute
mix zone
m
50
Chronic
mix zone
m
200
Port
depth
m
50
Effluent
flow
bbl/d
10000
6000
2000
E [fluent
salinityf)
psu
31.0007
Effluent
temp
C
16*
33.4S9
74.961
16.46
3S.4S9
74.961
16.46
38.4S9
Effluent
cone
ppm
100
3
1
u
Figure 6.4 Completed Diffuser tab for the Oil well problem.
Oil well ambient input conditions
The discussion about the linear and non-linear equations of states given in the section
Salinity, temperature, and nascent density is not repeated here. Once again, the ambient temperature
is estimated simply to define the problem in terms of the more accurate non-linear equation of state.
The corresponding ambient input values are given below. Once again, remember, to change
the units (salinity/density column and concentration) before entering the data.
Measurement depth or height
Current speed
Current direction
0, 50, 100m
0.115m/s
90deg (same as port discharge)
6.5
-------
Ambient density
Ambient temperature
Background concentration
Pollutant decay rate
Far-field current speed
Far-field current direction
Far-field diffusion coefficient
25.1, 25.6, 26.1sigmaT (OT) at depth
15C
0 ppm
Os-1
0.115m/s
90deg
0.000462m0.67/s2, m2/3s"2 in more elegant
format
The discharges are discharged about from mid-depth from platforms in water of about 100m
depth, so the input depths are realistic.
From the value of zero in the first column, first row, it is apparent that the values are depths.
Ambient data was apparently collected at depths of 50m and 100m. The bottom density value would
not be required if the salinity Extrapolation (btm) is set to Extrapolated. The completed ambient
table should look like Figure 6.5.
Ambient Inputs
An
Depth or Height
Extrapolation (sfc)
Extrapolation I btm)
Measurement unit
blent file list
Filename
Oilwells.001.db
Measurement
depth or height
m
0
50
100
Current
speed
depth
constant
constant
rn/s
0.115
Current
direction
Ambient Ambient Background
densit^") temperature concentration
depth depth depth depth
constant constant constant constant
constant constant constant constant
deg RI^H C ppm
90
25.1 15 0
mjjjjjjj
26.1
Pollutant
decay ratef]
depth
constant
constant
s-1.
0
Far-field
current speed
depth
constant
constant
rn/s
0.115
Far-field
current direct
depth
constant
constant
deg
90
Far-field
diffusion coeff
depth
constant
constant
m0.67/s2
0.000462
Figure 6.5 Completed ambient table for the Oil well problem.
Completing the Special Settings tab
The Custom graph coords, radio button cluster on the Graphics settings panel allows one
to specify the coordinates of the custom graph. By defining the abscissa and the ordinate, the x and
y-axis, respectively, a customized graph can be created. For the sake of practice, the plume diameter
versus distance along the plume might be selected. Click on the Abscissa (x) radio button and select
y-posn (both the discharge and current are in the y-direction, 90 degrees from the x-direction). Then
click on the Ordinate 1 (x) button and select P-dia.
To avoid cluttering the 4-panel graphic, the starting case and maximum number of graphs
to be plotted may be specified as shown in the Start case for graphs and Max detailed graphs edit
6.6
-------
boxes (starting case 1 and number of cases 3). The completed Special Settings tab should look
something like Figure 6.6.
Running the models
The models appropriate to this problem are UM3 and DKHW because they are the only
submerged, single-port discharge models in VP. Figure 6.7 shows that UM3 is the target model,
hence the square blue icon with the yellow plume on the diffuser or ambient tabs might be used to
run that model. Alternatively, the hot key, , could be used to run UM3. The 4-panel style
graphics are shown in Figure 6.7. The display has been customized according to Section 2.2.5.
Graphics settings
4-panel
dilution
P concentration
C custom
- Custom graph coords. -
(~ Abscissa (K)
<* Ordinate 1 M
(~ Ordinate 2 (y)
Custom variables
Start case for graphs Man detailed graphs
Diffuser port contraction coefficient [|
Light absorption coefficient
|0.16
PDS sfc. model heat transfer —
r Low (T Medium
High
WRUELD/FREIELD input variables
Output medium —
P Tent Output tab
Output to file
-
Selection List
Selected Variables
Arab-cur
Amb-sal
P-dia
4/3Eddy
Dilute
y-posn
Text output forma
Standard output
C Brief output
Figure 6.6 Completed Special Settings tab for the Oil well problem.
6.7
-------
Plume Elevation
20
Ambient Properties
30
r
D
40
— Plume profile
— Plume Profile
• Plume Bndry
* Plume Bndry
10 15 20 25 30 35 40
Horiz. Distance from Source (m)
50
25.4 25.6
Density (sigma-T)
g
•
______
s
\
_____
^
./
- Plume path
- Plume path
• Outline
• Outline
-20 -15 -10 -5
10 15 20 25
West-East (m)
Plumes Dilution Prediction
1,400:
1,200:
1,000
o SOD ;
600-
400-
200:
0
30
40 50 60 70 80 90 100
Horiz. Distance from Source (m)
Figure 6.7 4-panel style graphics for the Oil well problem. UM3 model predictions, cases 1-3.
Summary graphics
Plumes
Wait for minimized DOS window to finish;
then close it to continue
To continue with the comparison, the DKHW model
should be run next. First go to the graphics tab and select 2
(blue) from the Series radio cluster. Next select (run) DKHW
from theModels menu. The DOS window will appear which will
automatically close depending on Windows system settings, or,
it may have to be closed manually after the word "finished"
appears in the DOS window's title bar. Because the manner of
the window closing is unknown, VP displays the message shown Fjoure 6.8 DOS close message
in Figure 6.8 as a reminder to close the DOS window after the
finish message appears. The summary dilution graphic is shown in Figure 6.9. Note that the mixing
zone values (triangles) have been cleared off the display with the Clear Ib and Clear 2b buttons.
6.8
-------
Near-field and Mixing Zone Dilutions
1,900
1 ,800 -
1 ,700
1 ,600
1,500
1,400
1,300
1 ,200 •
1 ,1 00 -
1 ,000
700
300
200
100
n
-; 1
*
_. J •
f
' : B :
> : ' " i" '": •
: : ; 4
: • : :
: «. * *
•
4-
^ ;
A :
^ ;
I Near-field dil
* Near-field dil
A Mix zone dil
V Mix zone dil
456
Case sequence
10
Figure 6.9 A comparison of UM3 (red squares) and DKHW (blue diamonds).
Figure 6.9 demonstrates the potential value of Visual Plumes as a way to compare different
models to lay the foundation for model improvement. The substantial differences in runs 3-6 are
current topics of investigation. From continuity it might be concluded that the UM3 predictions are
more correct for the three middle runs than is DKHW. But, to make a value judgement is not the
point of exercise, it is entirely possible that in some range of conditions continuity would favor the
DKHW model. Furthermore, DKHW may generally give better estimates of centerline dilutions,
compared to UM3.
The important point is that VP, as a platform for competing models, can facilitate the process
of modeling development by identifying areas of disagreement. In the future, it is foreseen that this
capability will be further enhanced after the capability to display verification data together with
predictions is added.
Custom graph
To complete the discussion, note that the custom graph shows a zigzag curve of plume
diameter at maximum rise. The units are in inches, consistent with the units on the diffuser tab. To
display the graphic in meter units, it would be necessary to change the Port diameter units on the
diffuser tab to meters.
6.9
-------
In general, UM3 displays the most complete graphics. For example, there is no zigzag curve
for DKHW. The reasons are twofold, first, UM3 was essentially co-developed with VP whereas
DKHW is an independent application, and second, in some cases the independent models must be
modified to output the variables required by VP to plot specific graphics.
6.2 The Tidal Pollution Background Buildup Capability
As large populations live in coastal areas and many industries are located there, discharges
to estuaries and tidally influenced rivers and channels are not uncommon. Such waters are
significantly influenced by the tides, causing fluctuations in the velocity of the channel and even
periodically reversing the sense of flow, from downstream to upstream. If there are flow reversals,
then, even in the absence of diffusion, the conditions exist to cause a buildup of pollution from a
particular discharge in the receiving water. During periods of flow reversal, the receiving water
loaded with pollutants from the source in question can travel upstream. On returning on the ebb tide,
the polluted volume of water passes over the discharge a second time, or even multiple times if the
freshwater discharge is relatively small compared to the tidal flow. Thus, the discharge participates
in raising the ambient pollution background, over and above what might otherwise be there due to
the presence of other nearby sources or to natural occurrence or distant sources.
General theory
If these waters are reasonably one-dimensional in character, VP has a simple way for
estimating the buildup of background pollution that is self generated. The general approach is fairly
simple, ignoring the influence of most of the channel details, at least upstream and downstream, and
dispersion on distribution of pollutants. It depends only on knowing the cross-sectional area of the
channel at the point of discharge and the water velocity in the channel as a function of time.
Consequently, it must be used with the time-series capability. At the source a representative reach
of channel is defined which should be small to prevent the discharge over a period of time from
being distributed over a volume of ambient water that is unrealistically large. That would tend to
underestimate the level of background. On the other hand, for the sake of memory (currently 200
bins of storage), the fetch length must be large enough to avoid overflowing the upstream end of the
array, since information of that pollution would be lost. VP reports when the upper limit of the array
is exceeded, in which case the fetch length should be increased. If the fetch length is not increased,
one symptom of an inadequate fetch length is the maximum reported concentrations begin to
decrease after peaking (loss of pollutant). This might happen after building up to a maximum
sometime in after the first week or so of the simulation.
The terms bin, cell, and fetch length are used synonymously. The cell represents one in a
series of ambient water volumes that are continuously connected to define the tidal estuary.
Mass conservation only
The model is mass conservative, however, an important underlying assumption is that no
redistribution of carrier water from the source is necessary. In other words, all volume contributed
by the source is maintained in the fetch element to which it was discharged whenever that element
6.10
-------
passes over the point of discharge until that element finally ceases to pass over the discharge due
to the presence of freshwater flow or until the fetch element reaches the coastline and fails to return
on subsequent tide cycles. That is to say unnatural water elevations can be implied by this approach
that would be eliminated if the discharged water were routed by a hydrodynamic model. As a result,
comparison between measured and observed concentrations at any given time may be adversely
affected. However, over a long period of time, considered statistically, the approach is expected to
give realistic results. In other words, while a modeled high concentration may not be observed at the
stated time, such a measurement is likely if flow conditions continue to follow the same pattern.
More assumptions
This approach is most convenient when the source is isolated from other sources, so that
"natural" background is easily defined, and when the source is sufficiently far upstream so that a
fetch element does not reach the mouth of the channel during a single tidal cycle. If the natural
background is known, it may be entered as a time-series file, unless it is zero or invariant in time,
in which case it may be entered as constant (at least at any given depth).
The mouth of the channel must be established by specifying its bin (array element) at the
start of the simulation, actually, time zero, when the source is assumed to discharge to element 100.
This is done by estimating the volume of water existing between the source and the channel mouth.
Dividing this volume by the fetch element volume results in the number of bins that must be
subtracted from 100 to establish the initial location of the channel mouth. If this number is greater
than 100 and it is known that a fetch element can reach the mouth within one tidal excursion, then
the length of the fetch element should be increased to reduce the number of elements to under 100.
However, if that is not the case, maximum resolution should be pursued with the first restriction in
mind, in other words, the upstream distance should be sufficient to avoid the loss of information
about the content of the fetch at that terminus.
If tidal velocities are not specifically recorded and available, they can sometimes be
estimated or synthesized from knowledge of maximum current speeds under known flow conditions.
A simple harmonic program might then be used to generate a time-series current record, including
the effect of freshwater drift in the calculation.
Also, since current velocity in VP is a vector quantity, both speed and direction must be
provided. Speed must always reported as positive because direction determines the sense of flow.
If current velocity is actually recorded, any direction in a given 180 degree sector will represent
upstream flow and the remaining sector will represent downstream flow. (Water movement is
reported in the direction toward which it flows, opposite the convention used for winds.) On the
Settings tab the user specifies the central upstream direction. For example, for western coastline and
a channel oriented west to east, 90 degrees would represent the central upstream direction.
6.3 Advanced application: time-series files
6.11
-------
The following problem has two parts. Part one involves a conservative pollutant, meaning
that it does not decay over time. Part two involves a non-conservative pollutant that does decay with
time. This problem is based on a publicly owned sewage treatment work (POTW) on the East Coast.
The discharge is seaward of tidewater, but consists mainly of freshwater, in other words it discharges
into a tidal river. The effluent has secondary treatment. It should be noted that in the second part the
effluent concentration of bacteria of 1,000,000 colonies/100 ml, which is used in this problem, is not
realistic for secondary treated waste. A high value is chosen to demonstrate the interplay of the tidal
background pollutant, the pathogen model, and the total concentration. The POTW analyst wants
to run a number of cases to determine the concentration of both the conservative and
non-conservative pollutants over time. In order to meet regulatory requirements, the POTW must
demonstrate it can meet water quality criteria to be issued a discharge permit not requiring additional
treatment.
The projects are bundled with the VP software and are called MD_metal and MD pathogen
respectively.
6.3.1 Conservative pollutant
Diffuser table input
To set up VP to show all column headers that are relevant to a time-series application, the
Tidal pollution buildup option should be checked on the Model Configuration checklist.
The diffuser and flow input values are given as follows:
Port diameter O.lm
Port elevation 0.2m
Vertical angle 90deg
Horizontal angle 90deg
Number of ports 12
Port spacing 0.455m
Starting time 1 s
Ending time 720 hours
Time increment O.Shr
Acute mix zone 10m
Chronic mix zone 50m
Port depth 5.79m
Effluent flow leave this column blank. The effluent flow is changing over time, therefore,
time-series file will represent the values.
Effluent salinity Opsu
Effluent temperature 28.42C
Effluent concentration 65ppm
Creating diffuser table time-series files
6.12
-------
Time-series files are created in spreadsheets or word processing programs and are brought
into VP as ASCII files. In other words, when you save the file in a word processing program using
save as option, choose the Save as an ASCII file delimited text option. Save the file to a name that
has the same name as the project, and a suffix the same as the type of data file. For example, in this
case, the time-series file is for effluent flow. The extension for flow isflo, therefore, the full name
should be MDjnetal.flo.
There is a standard format that must be followed when creating time-series files. The first
line is always a header line. On the header line, the first number is the time increment used for this
time-series file. This will be dictated by the measurement time interval of the data provided by the
POTW. The time increment is assumed to be 1.0 hour. The second value on the header line is the
number of records in the file. Here a daily record is assumed to be available, hence 24 records. The
next value on the header line is the unit of measurement, literally the unit as it is spelled on the
appropriate unit popup list, m3/s. Following the unit is the optional name of the project followed by
its extension.
The next line should contain the flow at the start time (in other words, starting at time zero)
and proceed with flows on each line representing the flow at the increasing time increments. For
example, the first five lines (the header line and four data lines) should look like the following list.
A fragment of the effluent flow input file
1.0 24.000 m3/s MD_metal.flo
0.155
0.170
0.194
0.225....
There should be 20 additional lines of flow input representing the flow over 24 hours. If the
model is run for a time that is longer than the number of records present in the time-series, the
records recycle, starting over at the beginning. In this case because the number of records is equal
to a 24-hour period, the 25th hour period (the next 24-hour period) starts back at the beginning
record.
After saving the effluent flow file as an ASCII file with the name given above it is ready to
link into the proj ect. To do so click on the click for file in the cell under the Effluent flow label in the
Time Series Files (optional). Be sure that the borrow references the right proj ect path and name, e.g.,
c:\plumes\MD metal. Click on the borrow edit box to navigate to the right project if necessary.
6.13
-------
Diffuser, How, Mixing Zone Inputs
Start
spacing |time
Ending
time
Time
increment
Acute
Chronic
Port
depth
Effluent
flow
Effluent
salinity!']
hr
psu
> 0.1
0.2'j 90 90 12 0.455
20
0.5 101 50 j 5.79
Model Configuration
_ Brooks far-field solution
-------
Ambient table input
Input values into the Diffuser and Ambient tabs. The values used in this example problem are:
Measurement depth or height
Current speed
Current direction
Ambient density
Ambient temperature
0 and 5.79m
Leave blank, input from time-series file
Leave blank, input from time-series file
Opsu
28.4C
Ambient Inputs
Depth or Height
Extrapolation (sfc)
Extrapolation (btm)
Measurement unit
>
Measurement
depth or height
m
0
3.79
Current
speed
depth
constant
constant
m/s
Current
direction
depth
constant
constant
EH^^HI
HHHH
Ambient
salinity
depth
constant
constant
psu
°
Ambient
temperature
depth
constant
constant
C
28 .4
Background
concentration
depth
constant
constant
col/dl
0
Pollutant
decay rate(:':)
depth
constant
constant
s-1
0
n/r
dept
con;
con:
m/s
Figure 6.11 Ambient table input, current speed and direction columns are blank pending time-
series file linking..
Background concentration
Pollutant decay rate
Oppm
Os-1
The ambient table should look something like Figure 6.11. Notice that the current speed and
current direction columns are left blank pending time-series files being linked in.
Creating ambient time-series files
The time-series file may be created in the same manner as above and saved as an ASCII file.
The naming of ambient time-series files is a little different than it is for the diffuser time-series. The
base name for time-series files is the ambient table file name in which the db extension is replaced
by a three-letter extension specifying the variable contained in the file. See section 3.4, Files and
Filename Conventions. The names areMD metal. 00Lspd and MDjnetal.001.dir.
The Ambient time-series files have a standard format that is slightly different than that of the
Diffuser time-series files. The first line is similar with the first value being the time increments,
followed by the number of records in the file, followed by the literal name of the unit. After that, the
Ambient time-series files differ from those of the Diffuser tab. Differences include: the measurement
depth or height, extrapolation information both at the top of the water column and the bottom of the
water column, the units of the depths at which the measurements were made, the depth in those
units, and the file name. If the value is 0 after the units, the data is assumed by VP to be depth-based
6.15
-------
(referenced from the surface), a positive value would indicate that the input is height-based
(referenced from port depth). For example, the first six lines of this current speed time-series file
would appear as follows:
0.5 1920 m/s 0 constant constant m 0 5.79 MD_metal.001.spd
0.16590.1659
0.31550.3155
0.4462 0.4462
0.5498 0.5498
0.61960.6196....
Do not add blank lines at the end of the file.
As you might have noted from the first line of this time-series, there are 1920 records (or
rows of data) in this file. There are that many different current records. Tidal currents cycle
approximately over a lunar month (although the lunar-solar cycle is much longer, approximately
18.6 years). The value of 1920 derives from the longest period in the synthetic record. To use the
time-series file that has already been created for these different currents, click on borrow edit box
and navigate to the appropriate time-series reference file, hereMD metal.001.db. The time-series
file for the current direction is set up the same way. Both are linked in clicking on the corresponding
click for file cell.
The completed ambient tab should look something like Figure 6.12.
Time-Series Files (optional)
Borrow time-serie j files from project j C:\Plumes\MD_metal. 001
Time-series filename
Time inclement I hrs)
Cycling period
File measurement unit
HEiHSffi
0.5000
1920.0000
m/s
C:\PlLimes\MD.
0.5000
1920.0000
deg
click for file
click for file
click for file
click for file
click for file
click for file
click for file
Figure 6.12 Foreshortened ambient table showing current speed and direction time-series files
linked.
6.16
-------
Special settings
UM3 tidal pollutant buildup parameters
When the Tidal pollution buildup option is .
checked, the UM3 tidal pollutant buildup parameters Channel width (m) |42.98
panel components becomes visible on the Special channel seg. length (m)
Settings tab, as shown in Figure 6.13. The important
variable determined by the actual channel is the channel Upstream dir (deg) [90
width. The product of the channel width and the depth
of the channel should equal the cross-sectional area of '
the tidal channel. Based on this area and the average Coast concentration fo"
depth of the channel (5.79m) the channel width is ~~~
Computed to be 42.98m. Mixing zone depth (m) [Q
The upstream direction is also fixed by the
geometry of the channel. In this case the freshwater flow internal array cells used =
at the diffuser is approximately from east to west, hence
the upstream direction is 90deg. This variable should be Figure 6.13 The UM3 tidal pollutant
determined by the position of the current meter which, buildup parameters panel.
ideally, is located near the diffuser.
The discharge is located at bin 100, there are 100 bins upstream and 100 bins downstream
of the source. In this example the discharge is about 20 miles upstream, more than the distance of
a single tidal excursion, hence the coast bin is set to zero. In general, the position of the coastal bin
is computed by dividing the mean downstream channel volume by the mean volume of a single
channel segment. The volume of the channel segment is the product of the cross-sectional area and
the channel segment length. If the downstream volume is less than 100 segment volumes, then the
coast bin is identified correspondingly. For example, if the downstream volume is 50 times the
channel segment volume, then the coast bin is 50.
The concentration at the mouth of the channel may be specified in the Coast concentration
edit box.
Comments on optimizing UM3
The most tedious part of using the Tidal-buildup-of-background-pollution capability is
determining an optimum segment length, which is done by varying the channel segment length. The
key point to remember is that for the highest resolution the number of cells used should approach
the number of cells available, viz. 200. This is a trial and error process. VP provides feedback on
the number of array storage cells actually used in the simulation. A large value, but one less than
200, 199 would be optimum, indicates that no values were ever discarded at the upstream end. This
is the most mass-conservative approach. However, for many hours of simulation, the lowest
effective dilution will not always be associated with the largest number of cells. This is due to the
fact that the cell that contains the highest background may never again cross the diffuser at a time
that corresponds to the simulation time of any
subsequent run. Internal array cells used = 199
In this example, a process of trial and error
Figure 6.14 Optimum tidal resolution.
6.17
-------
result in the maximum number of cells, 199, as shown in Figure 6.14, indicating the optimum resolution.
Tidal buildup capability caveats
In the big picture, this capability should not be seen to be a substitute for actual, measured
background pollutant data. Rather, this capability is useful when measurements are unavailable or
for planning purposes. The pollutant-buildup capability does not include dispersive and other effects
that will influence pollutant concentrations in tidal rivers.
The custom graph
For a look at the synthesized tidal current speed the Amb-cur can be specified as the ordinate
on the Graphics settings panel on the Special Settings tab.
A UM3 simulation
Figure 6.15 shows the results of the UM3 simulation. The effect of pollutant buildup is
apparent. During the first couple of days dilutions show a regular pattern of high dilutions during
times of maximum currents and relatively low dilutions during times of low currents. However, as
background concentration increase, the effective dilution shows a steadily decreasing trend.
However, after about 10 days (500 half hour periods) the effective dilutions show an increasing
tendency.
6.18
-------
Near-field Dilutions
95
85
70
60
50
45
35
1 00 200 300 400 500 600 700 300 900 1 ,000 1 .1 00 1 .200 1 ,300 1 ,400 1 ,500
Figure 6.15 Month-long simulation showing the effect of tidal recirculation and background
pollution buildup on effective dilution. Note customized graph title (which is not maintained in
the list file).
The reason for the increasing tendency in effective dilutions in the middle of the period in
Figure 6.15 can be understood by studying the current speed plotted on the custom graph, Figure
6.16.
6.19
-------
Current Speed
100 200 300 400 SOO 600 700 800 900 1,000 1,100 1 ,200 1,300 1,400 1 ,500
Figure 6.16 A thirty day record of the synthesized tidal current speed in the channel.
Figure 6.16 shows the ambient current responding to daily ebb and flood tides in addition
to monthly spring and neap tides. The tendency for effective dilutions to increase beginning about
hour 300 (12.5 days, or at case 600) is associated with the transition from neap to flood tides. The
steady freshwater flow is sufficiently low that increasing flood tides temporarily increase the
effective dilutions.
However, the minimum effective dilutions occur around hour 500 (case 1000) as each
successive tide becomes weaker.
6.3.2 A pathogen
The difference between a non-conservative pollutant and a conservative pollutant is the
decay time, represented in VP by the Pollutant decay rate column on the ambient tab. Conservative
pollutants do not decay with time whereas non-conservative pollutants do. Pathogens are an example
of a non-conservative pollutant, which may decrease, or occasionally increase, with time. To create
a new proj ect that contains many of the values from a proj ect that has previously been created, open
the previously created project, which in this case will be the project created for the above exercise.
If starting from scratch, immediately after opening the MD jnetal proj ect, rename \iMD_pathogen
6.20
-------
using the Save project as command. Alternatively, the project is on the Visual Plumes CD and may
be opened directly.
Changes to the diffuser tab
A couple of minor changes to the diffuser tab are to the project memo and to the Effluent
cone column. The effluent concentration a million col/lOOml. In general, this column might be the
primary candidate for linking to a times-series file, proj ects would then be associated primarily with
the pollutant of concern. This is reflected by the modifiers metal andpathogen for these two related
projects.
Effluent flow borrow files on the diffuser tab
While there are reasons to separate pollutant constituents under different projects, many of
the time-series files are likely to be shared by projects. Such files should not be duplicated under
new names simply because the new project will search for time-series files using the new project
name as a reference. This is the purpose of the Borrow time-series from project edit box, to specify
a project from which to borrow time-series files. WhenUMS is run, VP will establish the time-series
files to link to the project. If a time-series file for the identified variable is found under the project
reference, that file is linked in. For the time-series file that name would be MD_pathogen.flo.
However, \fMD_pathogen.flo is not found, then VP will try to find a time-series file referenced to
the borrow project, i.e., it will search forMDmetal.flo.and link it to VP if the file exists.
The relevant portions of the diffuser tab are shown in Figure 6.17.
The Pollutant decay rate time-series file
The hardest part of the project is to create a time-series file for the Pollutant decay rate
column. This has been done; the file MD_pathogen.001.rat is included on the Visual Plumes CD
and should be ready to link to the proj ect. The beginning contents of the file with annotations, added
here but not found in the file, in italics are listed below:
6.21
-------
Project C:\Plumes\MDjmthogen
Coliform pollution on a tidal river. Linked files for effluent
flow, current speed, current direction, and decay (in
langleys/hr, the Mancini model using solar insolation
[representing the effect of UV radiation])
Ambient file list
Filename Cases
[
After run go to tab -
r Diffuse!
T Ambient
T Special
T Text
(• Graphics
-Units Conversion" j
-------
Custom graph
To show how solar intensity varies with time it
is useful to add the Decay variable to the custom
graph, as shown in Figure 6.18.
UM3 output
The UM3 effective dilution output for the
pathogen problem is shown in Figure 6.19. Again, the
graphical appearance of the output reflects customized
changes to the axes ranges. The corresponding solar
insolation is shown if Figure 6.20; it shows a basic
pattern of five sunny days followed by five very
cloudy ones.
Additional model input
D iff user port contraction coefficient 1 1
Light absorption coefficient
1
LC
KE
Graphics settings
Style
(~ 4-panel
r dilution
~ Custom graph coords. -
C Abscissa (x)
<* iCirdinate 1 (j)'j
r Ordinate 2 (ji)
!-ltflrt nflSR fnr nranhs
|0.16
C" concentration
(• custom
Custom variables
(Decay _J
May HRtflilfiH nranhs
Figure 6.18 Composite graph of relevant
parameters on the Special Settings tab.
85
-E*
.1
i 45
* 4D
o 4U
CX3
5
0 u
,
|*i ^ i *
r* i ^ i '
r*i ^ i 4
0 1DO 200 300 400 500 600 700 000 900 1,000 1,100 1,200 1,300 1,400 1,500
Case count
¥iftffe 6.49 not permanent.
Analysis
The effective dilution pattern shown in Figure 6.19 is not as distinctive as is the one for the
conservative pollutant (Fig. 6.15). The lack of pattern is due to the fact that the pollutant is
6.23
-------
constantly decaying in the background, thus the buildup of pathogen is not very great. The effect of
the long-term buildup of background pathogen is barely discernible except during cloudy periods
6.24
-------
6.4 Application of the surface discharge model, PDS
6.4.1 General comments regarding the PDS (PDSwin.exe) model
The PDS model uses only a subset of Visual Plumes input variables. As with the other
models, most of these must be defined on theDiffuser and Ambient tabs while the remainder are on
the Special Settings tab.
PDS assumes a shoreline, cross-sectionally rectangular surface discharge. The variables
defining the discharge include Conduit Width, Conduit Depth, Horizontal Angle, and Region of
Interest (ROI).
6.4.2 Sample PDS problem
Input conditions
This problem investigates a thermal plume generated by cooling water discharged from a
power plant into a large lake. Discharge is from a channel perpendicular to the lake's shore. A
parameter of interest is the distance along the plume centerline to the 2.0 deg C excess isotherm and
the total surface area within it. A large region of interest (ROI) of about 8000m may be tried to
capture the 2 degree excess temperature isotherm.
Input conditions for the problem are as follows:
Discharge channel width: 30 ft
Discharge channel water depth: 4 ft
Total discharge rate: 230 MOD
Discharge temperature: 27 C
Discharge salinity: fresh water, use 0.001 psu
Discharge angle: 90 degrees (in the y-direction)
Ambient temperature: 13 C
Ambient salinity: 0.001 psu
Ambient current: 0.005 m/s
Current direction: parallel to shore (zero degrees)
Surface heat transfer: Low for conservative case
As PDS is a surface discharge model the depth of discharge is zero. The depth on the first
row of the ambient table should also be zero. As always, a second ambient depth is required, assume
it is 10m. The rest of the second row should be left blank since PDS assumes well mixed ambient
conditions.
Go to the Special Settings tab. For a conservative result PDS sfc model heat transfer
parameter may be set to low. On the Graphics settings panel, set the custom graph to display plume
temperature versus distance, y-posn and Temp for the abscissa and ordinate respectively.
6.25
-------
The diffuser and ambient tabs are shown in Figures 6.21 and 6.22. The relevant input
parameter settings on the Special Settings tab are shown Figure 6.23.
Project C:Tlumes\A PDS run
Ambient file list
Filename Cases
Project "C:\Plumes\APDS run" memo|
A basic PDS run. Note, port depth defined in meters
controls the units on the output tabs.
C:\PlumesV\ PDS run.OOO.db 1 2
Alter run go to tab
T Diffuser
r Ambient
C Special
<* Text
(~ Graphics
Model Lonhgurahon
Units Conversion
Convert data
Label only
PDS
Brooks far-field solution
Graph effective dilution
Average plume boundary
Amb. current vector averaging
Tidal pollution buildup
Same-levels time-series input
- Case selection
Base or selected case
Sequential, all ambient list
Sequential, parse ambient
All combinations
t
Diffuser, Flow, Mixing Zone Inputs
Port Conduit
diameter depth
30 4
n/r nA Hor
angle
nA
m deg deg
90
n/r
m
n/r
£_
n/r
hr
n/r
hr
n/r
Chronic
mix zone
m m
8000
Port
depth
m
0
Effluent
How
MGD
230
Effluent
saiinitjf)
psu
0.001
Effluent
temp
C
21
Effluent
cone
ppb
100
Fronde number
0.302
Eff density fkq/m31 996.57617
Port vel I'm/si 0.153
P-dia (ml
9.1441
P-dia |
30.0
Case No.
1.0
Time Series-Files (optional)
Borrow time-series from project: plumes'* PDS run
Time-series filename
Time increment fhrs]
Time cvclina period
Measurement unit
Port
depth
imi^H
Effluent
flow
click for file
Effluent
saliniti/("]
click for file
Effluent
temp _,
click for file
Effluent
cone
click for file
Figure 6.21 A foreshortened diffuser tab showing A PDS run project input.
Depth or Height
Extrapolation (sfc)
Extrapolation (btm)
Measurement unit
Measurement
depth oi height speed
Ambient
temperature
n/r
constant
constant
m/s
depth
constant
constant
depth
constant
constant
deg
psu
depth dept
constant con;
constant cons
ppb
10
0.05
0.001
13
45
Figure 6.22 A foreshortened diffuser tab showing A PDS run
project input.
6.26
-------
Additional model input
Diffuser port contraction coefficient
Light absorption coefficient
J0.16
[•
PDS sfc. model heat transfer —
Low r Medium
High
Text output settings
Selection List
[Temp
Graphics settings
[-Style —
& 4-panel
C dilution
C concentration
C custom
NTLFTELD/FRMEL:
Custom graph coords.
C Abscissa (x)
. Depending on system
configuration, the DOS window may have to be closed when PDS is finished running. Figure 6.24
shows the 4-panel graphic display.
6.27
-------
Plume Ele
0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000
Horiz. Distance from Source (m)
Ambient Properties
-2
Densrty (sigma-T)
Plumes Dilution Prediction
8,000
7,000-
6,000-
? 3,000-
o 4,000-
| 3,000
2,000
1,000-
0
- Plume path
- Plume path
i Outline
• Outline
-1,000
0 1,000 2,000 3,000
West-East (m)
0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000
Horiz. Distance from Source (m)
Figure 6.24 A foreshortened diffuser tab showing^ PDSrun project input.
The most relevant project output is the custom graphic shown in Figure 6.25. Based on it,
the 2.0 degree excess temperature (15 C in this case) on the plume centerline is about 3400 m from
shore. (Surface plumes dilute much slowly than submerged plumes). VP output does not give the
areas within isotherms but the original PDS output does. This can be found by using a word
processing package or text editor to view the PDS.out file in the VP default directory; it lists a much
more detailed output than the VP text output given below. At the bottom of the file, you will see a
table giving surface areas within selected isotherms. For this example, you will see the 2.0 degree
surface isotherm encloses an area of about 4,000,000 m2.
6.28
-------
Surface Discharge Temperature Decay
200 400
600
800 1,000 1,200 1,400 1,600 1,800 2,000 2,200 2,400 2,600 2,800 3,000 3,200 3,400
Distance (m)
Figure 6.25 Temperature vs. distance for A PDS run. For one-time purposes, many of the
graphics display features have been modified for greater readability.
/ PDS surface discharge model
Case 1; ambient file C:\Plumes\A PDS run.000.db; Diffuser table record 1:
Temp
(C)
27.0
y-posn
(m)
10.56;
11.34;
25.84;
84.7;
121.0;
315.4;
344.9;
782.0;
790.2;
1572.2;
1580.5;
2952.2;
3001.4;
5499.4;
Cnduit
(ft
30.
wCnduit d H-angle
) (ft) (deg)
0 4.0 90.0
Amb-cur
Step (m/s)
1 0.05
2
15
28
33
93
105
225
226
367
368
536
542
788
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
05
05
05
05
05
05
05
05
05
05
05
05
05
Temp
(C)
27.0
26.
21.
18.
18.
16.
16.
16.
16
15.
15.
15.
15.
14
35
79
74
17
97
88
11
.1
54
54
07
06
.6
ROI Ttl-flo Eff-sal
(m) (MGD) (psu)
8000.0 230.0 l.OOE-3
Polutnt
(ppb)
5.000E-8
4
3
2
1
1
1
1
1
9
9
7
7
6
.762E-8
. 135E-8
.049E-8
.845E-8
.420E-8
.387E-8
.114E-8
.111E-8
.200E-9
.183E-9
.599E-9
.559E-9
.057E-9
Dilutn
0
2.0
2
3.
4.
5.
7.
7.
8.
9
10.
10.
13.
13.
16.
.1
19
88
42
04
21
97
.0
87
89
16
23
51
x-posn
(m)
-9.44
-10.
-22.
-61.
-82
-168
-179
-286
-288
-340
-339
-190
-181
545
14
05
63
.3
.5
.0
.7
.1
.1
.9
.6
.2
.4
6.29
-------
6.5 Ocean outfall problem
Background
This problem represents an actual technical assistance request, as it developed. Some
preliminary discussions are omitted. The email explaining the needs of a mixing zone analysis
included suggestions:
"A good analysis will have all the mandatory information on the diffuser and flow: port
diameter, number of ports, port spacing, vertical angle, bell or sharp edged port, port depth, effluent
flow, effluent salinity and temperature, and effluent pollutant cone..
"For ambient, we will need at specified depths, salinity and temperature, current speed (and
direction, if available), background pollutant concentration, decay rate (if not conservative). If all
isn't available, we will have to find other sources or use estimates.
"You say the applicant doesn't have much data. If they did, we could talk about time-series
files and more sophisticated analysis."
In response, the following information was provided:
"Will you still be able to do the initial dilution calculation for Sadog Tase WWTP? I am also
interested in determining what the dilution factor would be 49 feet from the diffuser (i.e., at the
boundary of the Zone of Initial Dilution under 301(h) regulations) and 100 meters from the diffuser
(per the mixing zone allowed under EPA's Ocean Discharge Criteria, 40 CFR 125.121(c)).
"I've been able to track down the following information for the Sadog Tase WWTP outfall."
Problem description
Data provided by the permit reviewer with comments by the analyst in italics. Note: some
parameters and conditions were changed to increase the instructive value of the problem.
1. Port diameter: 6 inches. (From AS-BUILT drawing: Sewer outfall (off-shore) detail trench area
and diffuser assembly, DWG. NO. SH-OS-004, SHT. NO. 4/4.)
{English units should be reminder to change the units before inputting data. ]
2. Number of ports: 6. The last three ports are closed (with a blind flange). The end of the diffuser
is also closed with a blind flange. (From AS-BUILT drawing: Sewer outfall (off-shore) detail trench
area and diffuser assembly, DWG. NO. SH-OS-004, SHT. NO. 4/4.)
[Some confusion about whether there are three open ports or six, therefore will do both analyses.}
3. Port spacing: 19.68 feet. (From AS-BUILT drawing: Sewer outfall (off-shore) detail trench area
and diffuser assembly, DWG. NO. SH-OS-004, SHT. NO. 4/4.)
4. Vertical angle: 90 degrees (?). Each port is on a "riser" which rises vertically from the diffuser
pipe lying on the sea floor. The upper portion of each riser makes a 90 degree turn, so that when
6.30
-------
viewed from the side (i.e., elevation view), diffuser ports open towards the viewer [therefore,
horizontal discharge, not 90 deg}. The opening of each diffuser port alternates 180 degrees from
the adjacent port. (From AS-BUILT drawing: Sewer outfall (off-shore) detail trench area and
diffuser assembly, DWG. NO. SH-OS-004, SHT. NO. 4/4.)
[Spacing is effectively 19.68ft if all ports are open, otherwise, twice that distance is assumed. Note,
for a diffuser with only three ports, end effects will be important if merging occurs. }
5. Bell or sharp edge port: The opening of the port is not a "square" shape, it is a "circle" shape.
Does this mean that it is "bell" shaped? (From AS-BUILT drawing: Sewer outfall (off-shore) detail
trench area and diffuser assembly, DWG. NO. SH-OS-004, SHT. NO. 4/4.)
[Note confusion about port shape; the sharp-edged port, assumed (see settings tab), could be tested
by changing the contraction coefficient to 0.61. ]
6. Port depth: 49 feet below sea level. (From 1995 NPDES application, Standard Form A.) [Note,
depth is the basis of the size of the mixing zone in 301(h) applications.}
1. Effluent flow: 3.0 MGD annual average (1998); 4.8 MGD (average daily design). (From Mike
Lee in fact sheet for 08/12/99 draft permit.)
[High flow is modeled. ]
8. Effluent salinity: 1.7 - 19.0. (From 1992 301(h) application, pp. 45 - 46.)
[As this is an ocean outfall, the lower salinities will generally produce higher dilution. However,
the very high effluent dilutions appear to be outliers. The reason for modeling 4.5psu no longer
known.}
9. Effluent temperature: 20.0 - 30.0 degrees Celsius. (Estimated range from 1992 301(h)
application, pp. 44 - 46.)
[Permit reviewer and analyst decided to model the range, i.e., both 20 and 30C.}
10. Effluent pollutant concentration:
Enterococci: 3,000 #7100 mL [analyzed past holding time of 30 hours]
Nitrate-nitrogen: 4.6 mg/L
Total nitrogen: 2.19 mg/L
Orthophosphate: 0.71 mg/L
Total phosphorous: non-detect [error?]
Unionized ammonia: 0.23 mg/L
Copper: 8.4 ug/L (using RP approach in 1991 TSD, statistically est. as high as 62 ug/L)
Nickel: 1.2 ug/L (using RP approach in 1991 TSD, statistically est. as high as 81 ug/L)
Silver: 1.5 (using RP approach in 1991 TSD, statistically estimated as high as 11 ug/L)
Zinc: 58 ug/L (using RP approach in 1991 TSD, statistically est. as high as 429 ug/L)
[Each pollutant could be the basis for another project (sub-project).}
6.31
-------
NOTE: CUC (permittee) staff have indicated that the effluent plume surfaces most of the time. This
is based on fecal coliform data collected at the surface above the outfall (i.e., they always find it at
the surface above the diffuser). Based on this assumption, do we need salinity and temp, data at
different depths, or is this fine for a first attempt modeling run?
[Information on stratification is not available but would be invaluable. As it stands, all that can be
done is to do a sensitivity analysis.}
11. Ambient salinity: 30 - 36 ppt.
12. Ambient temperature: 25 - 30 degrees Celsius.
13. Current speed: Assume 0.
[Zero current is not necessarily the most conservative assumption. Both zero and 5cm/'sec currents
will be modeled. The higher current case will be assumed to have a small density stratification.}
14. Background concentration: 0.
15. Decay rate: ?
[The pollutant modeled is Coliform. In tropical water a decay rate corresponding to a T-90 time of
one hour is fairly representative. With zero current, the travel time to the mixing zone boundaries
will be very long. A more realistic velocity might be 5cm/sec.}
Comments about currents and stratification
This problem is fairly typical of the kind of information available to the permit writer. As
will be seen, the available information often is not as complete as a scientist, or even, permit writer,
would like. For example, currents and density stratification are two variables that strongly affect the
initial dilution process, for which there frequently is limited data. After all, ambient sampling and
data collection is expensive. However, one of the strengths of VP is the ability to determine how
sensitive the problem may be to variations in conditions that are only partially specified.
You might try creating a project to analyze this problem on your own. The no-current
assumption is quite common, often being considered to represent a worst case analysis. However,
the far-field current cannot be zero (the effluent must be able to move to the mixing zone boundary).
Concerning the "worst-case" assumption, when the dilutions of interest are to be specified at fixed
distances, like mixing zone boundaries, the worst case may not correspond to the no-current
assumption, rather, to some higher current speed. It is easy to set up VP to determine likely
worst-case current speeds, as is shown subsequently.
The choice of graphing the effective dilution is actually irrelevant, since there is no
background pollution.
6.32
-------
Project C:\Plumes\Sadog Tase AugOO
Ambient file list
Filename
An example potentially involving four flow and discharge
scenarios and two ambient input files.
Ambient scenario 1: no current, no stratification.
Ambient scenario 2: 5cm/sec, small stratification
(C:\Plumes\Sadog Tase AugOaOOLdbT
- After run go to tab ~
T Diffuser
C Ambient
C Special
r Text
(• Graphics
Model Configuration
Units Conversion—
(• Convert data
<" Label only
_ Brooks far-field solution
Graph effective dilution
Average plume boundary
Amb. current vector averaging
Tidal pollution buildup
Same-levels time-series input
p Case selection —
f* Base or selected case
f Sequential, all ambient list
C Sequential, parse ambient
f All combinations
Diffuser. Plow. Mixing Zone Inputs
Parameters for selected row |
Froude number 23.23
Eff density [ka/m3) 999.0613
Portvelfm/sl 3.843
Time Series-Files (o
Time-series filename
itional)
Port
depth
EUS^^^I
Borrow time-series from project: | C:\Plumes\Sadog Tase AugOO
Effluent
flow
Effluent
«**f]
Effluent
temp
Effluent
cone
click for file click for file click for file click for file
Figure 6.26 Diffuser tab for the Sadog Tase outfall.
Diffuser tab representation
The diffuser tab is shown in Figure 6.26. Notice the association of several ambient files
shown in the Ambient file list. Once these files are cloned from a template file, they can be added
to the list by right-clicking the Ambient file list window. Clicking on the name will then place the
selected file on the diffuser and ambient tabs where it may be modified as appropriate.
Creating new ambient files and editing the Ambient file list
To create a new ambient file, from the
ambient tab select the Save ambient file as
command from the File menu. VP will attempt to
increment the current filename. If that file is
selected and already exists, you are asked whether
to overwrite the existing file. Generally, it is a good
idea to edit the filename before accepting it.
However, if a name is overwritten, the filename
will appear twice on the Ambient file list. The
redundant name can be removed on the diffuser tab
Add file
Add all xxx
Insert file
Insert all xxx
Remove selected files
Remove selected and following files
Help
by selecting the desired file and then right clicking _. , „ . ,. «,. *. ,•
J . , . _. ,%_ „, & Figure 6.27 Ambient file list edit pop-up
to reveal the pop-up menu in Figure 6.27. Choose
1 menu.
6.33
-------
the Remove selected files command to remove the redundant filename from the list. The file is not
affected, i.e., it is not deleted.
The unstratified ambient scenario
The unstratified ambient scenario is shown if Figure 6.28. For greater readability, the right-
click menu has been used to increment the font size. The user may wonder why this was done above.
Ambient Inputs
Measurement
depth or height
m
Current
speed
Current
direction
Ambient
salinity
depth depth depth
constant constant constant
constant constant constant
rn/s
deg
Ambient
temperature
Background
concentration
depth depth
constant constant
constant constant
psu |C
> 0 0 0 29
50
ppb
30 0
Pollutant
solar radn(")
depth
constant
constant
52.651
Far-field
current speed
depth
constant
constant
rn/s
0.01
Far-field
current direct
depth
constant
constant
deg
0
Far-field
diffusion coeff
depth
constant
constant
m0.67/s2
0.0003
Figure 6.28 Unstratified ambient scenario showing increased font size using right-click menu.
6.5.1 The Mancini bacteria decay model
Measurement
depth or height
Depth or Height
Extrapolation (sfc)
Extrapolation (btm)
Measurement unit
rn
Pollutant
decay rate[x
Pollutant
| solar radnf
depth
constant
constant
T90hr
depth
constant
52.651
The actual input to the
Pollutant decay rate column was one
hour T-90 time (90 percent of the
organism will die in one hour). The
unit was then changed to ly/hr showing
that for the given conditions of
salinity, temperature, and absorption
(no effect, as this is a surface value), a
one hour T-90 time corresponds to a
solar radiation intensity of 52.651 ly/hr.
Some points should be
emphasized. The Mancini
(1978) can be used at different levels.
The UM3 is model is the only model that can dynamically implement the Mancini model at depth,
in other words, using absorption coefficient to modify the decay rate at depth. For the other models,
VP will convert the solar insolation values to the primary units, per sec. Even VP will give different
predictions depending on whether or not the Mancini model is implemented dynamically, which
happens when the chosen unit is ly/hr.
o;
15.24
1
140.66
Figure 6.29 Composite graphic showing a conversion
mode from decay rate ^o the corresponding solar intensity.
6.34
-------
Figure 6.29 shows how a conversion from T-90 time to ly/hr works in the Pollutant
decay/Pollutant solar radn column. First inputting T-90 time values and then converting to solar
intensity units (ly/hr) yields the surface solar intensities required to cause the desired T-90 time at
depth. This shows the effect of the absorption of radiation in the water column. At the surface it only
requires 52.65 ly/hr to produce a decay rate T-90 time of one hour, however, at 15.24m (50ft) it
would require 140.7 ly/hr to produce the same decay rate. In reality, the T-90 time will increase with
depth; bacteria in submerged effluent have a much better chance for survival.
Known bug. This exercise revealed a bug. The Mancini value is not properly converted when
the water column (first column on the ambient tab) depths are in units other than meters. Thus,
before using the Mancini model the water column depths should be returned to units of meters. The
Measurement depth or height column is unique, to change its units one first double clicks in the blue
units cell.
6.5.2 Assumptions, the user's domain
Information provided by the analyst includes the assumption about an open-water far-field
diffusion coefficient. A value that is in widespread use is 0.000452. Here a more conservative value
of 0.0003 is used.
The extrapolation (sfc) cell in the header grid above the ambient table shows that values
above and below the indicated depths will be held constant. However, if there were additional
entries in any column in the first row, VP will interpolate the indicated values between the given
depths, but extrapolate outside of those depths if the constant specification were changed to
extrapolate.
Graphic output with pan and zoom
The graphical output for the unstratified base case is shown if Figure 6.30. To run the base
case with the stratified case, one would click on the stratifed ambient file in the Ambient file list. For
the plume elevation, the pan capability (right-button drag) was used to center the graphic. Other
adjustments are apparent. A help button is available to provide instructions on manipulating the
graphics.
6.35
-------
Plume Elevation
Amta
, 220^
5 10 15 2(
Horiz. Distance from Sou 200 -
Plan View
160
-e
o
"5
o
o-i
100-
50-
0
-50-
-100-
^
^^
•
•
•
"
v
•
i— 1 d.n "
o :
^ 1201
a
on -
d.n "
0-
c
•
/
f
I
1
} 5
m
m
-**--- -
0 1C
— Plume profile
— Plume Profile
* Plume Bndry
* Plume Bndry
20-
Plumes Dilution Prediction
40-
300
0 100 200
West-East (ft)
Figure 6.30 Unstratified ambient scenario output (retouched graphics).
50 100 150 200 250 300 350 400
Horiz. Distance from Source (ft)
400
The plan view shows the far-field algorithm predictions as the widely spaced points. Note
that VP plots a single plume up to the point of merging or until the initial dilution phase is complete.
If plumes do not merge before the far-field algorithm takes over, the dispersion will be considerably
underestimated.
The dilution panel shows the classical difference between the initial dilution phase (rapid
increase in dilution) and the far-field phase (less rapid dilution).
6.36
-------
Plume Elevation
Ambient Properties
50-L2
150
100
50]
0
-50]
-100
-150
10 20 30 40 50 60
Horii. Distance from Source (ft)
70
Plan View
ir
m
i *
••JT
Jin
B
m
m 4
•
•* •
•*•
s
•*
i
•
•*
f
•
0 2 4 6 8 10 12 14 16 18 20 22 24
Density (sigma-T)
Plumes Dilution Prediction
0 100 200 300 400
West-East (ft)
Figure 6.31 Stratified ambient scenario output (retouched graphics), UM3 (red), DKHW (blue).
0 10 20 30 40 50 60 70 80 90 100
Hnri7 Distance frnm Source fffi
Stratified case
Figure 6.30 shows UM3 and DKHW runs for the stratified scenario. The difference for the
stratified scenario is the entry of 29C at 50ft depth. The stratification is plotted in the upper-right
hand panel. The plumes still reach the surface but the effect of stratification is apparent. DKHW
predicts considerably less rise, therefore the predicted plume has a much longer initial dilution
phase. This effect is exaggerated by the fact that UM3 stops the initial dilution calculation upon any
portion of the plume impacting the surface whereas DKHW continues this phase until the centerline
hits the surface. The greater DKHW pollution prediction is also apparent in the dilution graphic.
6.37
-------
A bug is apparent in the plan view. DKHW far-field prediction is based on the unmerged
waste field width, whereas UM3 uses the width of the waste field (the sum of one plume diameter
and the width of the diffuser). This discrepancy may be corrected on any future version of VP.
Running multiple cases
To run all cases, select the Sequential, all ambient list option on the Case selection radio
group. Existing text and graphics might first be cleared with the appropriate buttons on the text and
graphics tabs.
Near-field Dilutions
Qcn
ijn
"4 II II
280
??n
160
100
40
j
i
t ..A
1
K
1
i
,j
{
1
4
"•
W-
r
1
>
]
.. |
>
i
1
4
>
1
e
t
1
0123456789
Case sequence
Figure 6.32 Stratified ambient scenario concentrations, UM3 (red square), DKHW (blue).
Graphic customized to improve visibility of title and labels.
10
The dilutions for the unstratified case are lower than for the stratified in part due to the
higher current and the surface impaction condition. To show cases where higher currents lead to
reduced dilution, more experiments are necessary. Also, it should be borne in mind that the mixing
zone predictions (graphed by VP as triangles) have been cleared from Figure 6.31.
6.38
-------
Text output
Below is a partial listing of the text output for this problem. The text was edited in VP to
remove excessive lines of output (indicated by ....). Also, cases 1,2, and 8 are shown for UM3,
followed by a sample for DKHW (Case 1).
Diffuser table record 1:
P-dia P-elev V-angle H-angle Ports Spacing AcuteMZ ChrncMZ P-depth Ttl-flo Eff-sal
(in) (ft) (deg) (deg)
6.0 3.0 0.0 0.0
Froude number: 11.64
Amb-cur P-dia Polutnt
Step (m/s) (in) (col/dl)
0 0.0 6.0 17000.0
100 0.0 39.75 2427.7
200 0.0 108.3 482 .6
248 0.0 188.3 181.0
Plumes not merged, Brooks method may be overly conservative.
Const Eddy Diffusivity. Farfield dispersion based on wastefield width of
cone dilutn width distnce time
(col/dl) (m) (m) (hrs) (ppb) (ly/hr) (m/s)(m0.67/s2)
106.839 93.38 20.58 14.94 0.205 0.0 51.61 0.01 3.00E-4
53.09 104.5 2.694 0.0 51.61 0.01 3.00E-4
file C:\Plumes\Sadog Tase Aug 00.001.db; Diffuser table
Dilutn
Plumes not merged, Brooks method may be overly conservative.
Const Eddy Diffusivity. Farfield dispersion based on wastefield width of
cone dilutn width distnce time
(col/dl) (m) (m) (hrs) (ppb) (ly/hr) (m/s ) (mO . 67/s2 )
179.181 77.03 15.93 14.94 0.061 0.0 51.61 0.01 3.00E-4
file C:\Plumes\Sadog Tase Aug 01.002.db; Diffuser table
Ports Spacing Temp
0 (ft) (C)
3.0 39.36 20.0
Froude number: 24.95
Amb-cur P-dia Polutnt Dilutn x-posn
Step (m/s) (in) (col/dl) () (ft)
0 0.08 6.0 17000.0 1.0 0.0;
100 0.08 40.21 2343.2 7.146 7.446;
200 0.08 192.0 314.7 51.68 41.12;
245.0 217.9 73.81 49.09; acute zone,
107.7 144.7 67.32; trap level, surface,
/ DKHW
6.39
-------
Case 1; ambient file C:\Plumes\Sadog Tase Aug 00.001.db; Diffuser table record 1:
AcuteMZ ChrncMZ P-depth Ttl-flo Eff-sal
P-dia P-elev
(i
6
Froude
Step
0
2
26
27
39
48
49
53
54
56
58
60
63
64
68
69
74
7 9
83
n) (ft)
.0 3.0
number :
Amb-cur
(m/s)
0.0
0. 08
0.08
0. 08
0.08
0. 08
0.08
0. 08
0.08
0. 08
0.08
0. 08
0.08
0. 08
0.08
0. 08
0.08
0. 08
0.08
V-angle
(deg)
0.0
H-angle
(deg)
0.0
Ports
0
6.0
Spacing
(ft)
19.68
11.64
P-dia
(in) (
6.0
16.42
24.92
25.67
39.45
60.08
62 .68
74 .72
79.13
87. 4
95.04
102.2
115.6
122. 0
147.5
153. 8
198.3
254. 7
288.8
Polutnt
col/dl)
17000.0
8812 . 9
5800.1
5632 . 9
3643.4
2329.1
2220.8
1795.7
1665.9
1449.0
1276.3
1135.2
919.1
834 .6
594.6
551.4
352.1
223 . 7
170.5
Dilutn
0
1.0
1. 929
2. 931
3. 018
4. 666
7.299
7.655
9. 467
10.21
11.73
13.32
14 . 97
18.5
20.37
28.59
30.83
48.28
76. 0
99.7
x-pos
(ft
0
2 . 9
3.8
3 . 9
5.4
7 . 7
8.0
9.4
9.9
10.
11.
12.
14.
14.
17.
17.
20.
22.
24.
. 52;
Plumes not merged, Brooks method may be overly conservative.
Const Eddy Diffusivity. Farfield dispersion based on wastefield width of 31.33
cone dilutn width distnce time
(col/dl) (m) (m) (hrs)(col/dl) (ly/hr) (m/s)(m0.67/s2)
154.586 99.78 33.01 14.94 0.0422 0.0 52.66 0.05 3.00E-4
42.065 116.5 48.62 104.5 0.54 0.0 52.66 0.05 3.00E-4
6.40
-------
7 Model Theory
7.1 Visual Plumes
The text in this section is presently limited. It is planned for expansion.
7.1.1 Bacteria models
The traditional implementation of pathogen decay in VP is a simple first order, or
exponential, decay. However, four-stressor (salinity, temperature, solar insolation, and water column
absorption) Mancini bacteria model (1978) is implemented in VP and described in limited detail in
Section 6.5.1. Further information may be found in Keyes (1999).
7.1.2 Tidal buildup capability
The tidal pollution background buildup capability is described in some detail in Section 6.2.
Future additions to this capability to include other main tributaries (or sources) to the tidal channel
are planned.
7.1.3 Nascent density
The simplest analogy to the nascent density effect in plumes is pond overturning in winter.
It is well known that the equation of state for water is non-linear. Unlike most substances that
contract continuously upon cooling, fresh water expands before freezing below about four degrees
Celsius. A pond cooling warming slowly in late winter may overturn because, as the surface water
warms above OC, it becomes denser than the bottom water with the result that the pond will
suddenly "overturn," with denser, but warmer, surface water replacing the colder, but less dense,
bottom water. This mixing will typically be accompanied by increased turbidity.
A similar principle can have profound effects on thermal plumes (Frick and Winiarski,
1978). Consider a fresh water thermal discharge at 60C to a uniformly cooled lake at OC. The
temperature in the plume will cool continuously to zero as it mixes in lake water (see Figure 7.1).
The density will increase correspondingly, and the plume will begin to rise, until the average plume
temperature approaches approximately 8C. However, below that temperature the plume's density
will be greater than the ambient density at OC and the plume will first decelerate its upward motion,
then reverse its upward velocity, and finally sink to the bottom.
For a long time it was believed that the nascent density effect was potentially important only
in cold, fresh receiving water. Many discharges, like the sewage effluent in Figure 7.1, behave in
the traditional way. However, some DOS PLUMES users found other circumstances in which the
7.1
-------
Density of Seauater
6(1
so
Temperature (C)
Figure 7.1 Density diagram for fresh and seawater. Three mixing lines are shown for a warm
brine, a typical sewage effluent, and a thermal discharge.
nascent density effect is important. Figure 7.1 shows the mixing line for a brine, perhaps derived
from a water desalination process, discharged to ocean water. It is discharged at about 42C and
43psu. As it mixes with seawater it first becomes denser, but, at below about 28C it also becomes
denser. This characteristic of starting buoyant but becoming denser has led to this process being
called the nascent density effect.
The fact that buoyant plumes, which ordinarily are expected to rise to the surface given no
ambient density stratification, can end up at the bottom of the water column has profound
7.2
-------
implications on regulatory decision making. It would mean that the benthic, not the pelagic,
biological community would be affected by the effluent.
File 7.2 shows plume dilutions from simulated plumes all possessing the same buoyancy on
discharge (effluent density in all cases is 10 sigma-T units, or 1010kg/m3), discharging to three
ambient scenarios (ambient discharge level density about 15.4 sigma-T units), and otherwise
identical. The eight effluent cases have temperatures ranging from OC to 70C in IOC increments,
with salinity adjusted to give the constant effluent density. Based on similarity, as expressed by
sharing the same densimetric Froude number, all plumes should perform identically. However,
dilutions vary widely at maximum rise.
This example illustrates the weakness of some schemes that use linear similarity theory to
categorize flow, as these will lead the analyst to conclude that all of these plumes will develop
identically in these three flow scenarios. On the other hand, the agreement between UM3 and
DKHW is remarkably good in this range.
Additional information on the nascent density effect is available in the DOS PLUMES
manual and in the PowerPoint presentation lagdensity.ppt file on the Visual Plumes CD (Winiarski
subdirectory). This is rudimentary guidance planned for completion.
Near-field and Mixing Zone Dilutions
1,UUU
1,500
1,400
1,300
1,200-
1,100
1,000
900 •
1 800
b
700
600
300
400-
300
200-
100
0 -
I
; 4. : ; : : : i i : : :
"f " " : ; ' : ' " ' : ; ' ; :"
'. ± ' ' ': ':'.'.''':
t • ; 7 " '. i i : i i i "
f . .' ' . ... : , ;. . . .L : '•. . . .'
: :. . ...:.... ....: :. . .; ; ; .; .. ...: .. .
* : : * : - 1 i '] ; :
""••• t " : rt r- : r ; •; -=
^•-••^
i ; ; ; ;'"f i ! i ; ; •
T '. : : ! ;"" ;"" ">"" " *"" ' : "
'•- • » ; : ' : i : : » : :' •"
: - • • v ; t ; ;••:•••-•
: ; '-.... .: '. i ;. .. - : : f ;.. -
: • .. : ; •...». : ; : '... m . :
: , t ^ : • if*; • :f
2 4 6 8 10 12 14 16 18 20 22 24
Case sequence
• Near-field di!
» Near-field dil
A Mix zone dil
V Mix zone dil
• Verification
Figure 7.2 Maximum rise dilutions rrom eigm equal density erriuent now scenarios discnarg
to three ambient receiving waters. Red squares correspond to UM3 output, blue diamonds to
DKHW output.
7.3
-------
7.2 UM3 theory
7.2.1 Established theory
UM3 is a Lagrangian initial dilution plume model based on the UM model described in some
detail in Baumgartner, Frick, and Roberts (1994), also known as PLUMES (now DOS PLUMES to
differentiate it from Visual Plumes. The complete PLUMES manual is available on the Visual
Plumes CD in the 3rd Edition, DOS PLUMES directory (DOSManual subdirectory).
DOS PLUMES manual on the Visual Plumes CD
Two versions of the PLUMES manual are included on the CD, in the original WordPerfect
format (wpd files) and in pdf format. With time printer and graphics technology has changed
considerably and users typically have had difficulty printing their own manuals. In the CD version
many of the original graphics have been scanned and saved asjpg files. Unfortunately, this process
results in some degradation in graphic quality which is particularly noticeable in the/^version of
the manual.
7.2.2 Three-dimensional generalization
Single Ports: Visual Plumes UM has been modified for three dimensions. This change is
possible by using vector math and by generalizing the Proj ected Area Entrainment (PAE) hypothesis
(Winiarski and Frick, 1976; Frick, 1984). The modification adds a term to the PAE hypothesis which
represents the entrainment entering the plume element from the side represented by a vector pointing
at right angles to the plane formed by the instantaneous direction of motion of the plume element
and the gravitational acceleration vector. Thus, for example, a port discharging eastward will form
a plume element that will turn northward if there is a component of the current directed northward.
Multiple Ports: The behavior of multi-port plumes is the same as single-port plumes up to
the point of merging. After merging the sideway component of entrainment is distributed over all
plumes. The problem of parallel currents is solved by assuming that for angles of less that 20
degrees, measured between the plane of the individual plume element motion and to a horizontal line
at right angles to the local current, there is no further reduction in the effective spacing between
adjacent plumes, which would otherwise reduce to zero when currents are parallel to the orientation
of diffuser pipe. This approach is suggested by the findings of Roberts (1979)
7.4
-------
7.5
-------
8 Model Availability and Performance
The text in this section is presently limited. It is planned for expansion.
VP is available on CD. Until it may be obtained through EPA's Center for Exposure
Assessment Modeling, Ecosystems Research Division, Athens, GA, USA webpage:
ftp://ftp.epa. gov/epa_ceam/wwwhtml/products.htiTu Visual Plumes may be obtained by contacting
Walter Frick, frick.walter@epa.gov.
8.1 Model verification and comparison
The Visual Plumes models have a long history of verification beginning for UM3 in 1975
(Frick and Winiarski, 1975; Frick, 1984; Baumgartner, Frick, and Roberts, 1994). The DKHW
model is similarly represented by a long history (Kannberg and Davis, 1976; Davis, 1999).
Independent verification exercises are also available, e.g., Fergen, Huang, andProni (1994).
One of the aims of Visual Plumes is to provide a platform for independent mixing zone
models. In this vein, DKHW, NRFIELD, and UM3 are three models that are all designed to predict
the same behavior of plumes in the initial dilution region. They may be seen to be competing
models. By supporting competing models Visual Plumes is intended to encourage continued model
innovation.
One way to further encourage model development is to provide the means to compare model
predictions with experimental or field data. The Verify button on the graphics tab serves this purpose
by enabling the user to link in and display verification files and data. The Fan-Run-16 proj ect based
on Fan (1967) illustrates one way this capability may be used (Fig. 8.1). Expanded examples of
plume verification are planned for future releases of Visual Plumes.
8.2 Troubleshooting
8.2.1 Problems and solutions
Base case disappears from view
Use the scroll bar on the diffuser table to move it back into view.
File corruption
Files can become corrupted through a crash or other abnormal termination. Normally, at
program termination or before opening new projects (i.e., before storing the current project files),
VP inserts header information at the top of the database files that helps it interpret the data, e.g., the
U
-------
Plume Elevation
0.2 0.3
Horii. Distance from Source (m)
Figure 70 Comparison of plume trajectories and plume diameters: DKHW (blue shorter line)
and UM3 (red line) with Fan Run 16 (Fan 1967), jagged black line.
units of each column, the next time the project is run. These header lines are absent from the file
when the program terminates abnormally. When VP is next run it examines the input data to check
for the presence of the header information. If it does not find it, VP alerts you to the corruption. VP
will then attempt to reestablish the integrity of the file by reading the project List, if available. Thus,
unless the user has incorrectly modified the List file, a full recovery will be accomplished (except
for customizing details that are not saved in the List file). If a List file is not found, VP goes through
a standard recovery procedure that provides default header information, including primarily MKS
units (the units at the top of the list of units in each units popup) and other default data.
When a corrupted file message is issued, it is a good idea to check the units listed for all your
variables. If they are not what they originally were, select the Label only radio button on the diffuser
tab and change the units of each variable to the desired values. This will not change any of the
values, just the labels so they agree with the values. Once done, be sure to change back to the default
Convert data option.
File not found: linking time-series files after save as new name
If an old project that used time-series files is reopened and run, the File not found error
message can appear if in the interim the time-series files have been moved or renamed. Check to be
sure the time-series files exist and are in the correct project or borrow paths.
8.2
-------
Graphics panels are empty
If no graphics appear try using the Scale button to rescale the axes. If there is still nothing
shown, check the graphics settings on the Special Settings tab need to be revised. For example, the
Start case for graphs number may be higher than the number of cases run.
Parameters for selected row panel does not change
Calculation of densimetric Froude number and effluent velocity, and, conversion to density
on the Parameters for selected row panel are done only upon pressing the button. The other values
are updated when clicking on the cells in the diffuser table or on the tab key being used. Moving up
or down in the column using the arrow keys does not update the conversions.
When time-series files are linked in, only the first case is evaluated in this panel.
Using backup files to recover from a crash
Data corruption in VP is now fairly rare. An alternate way of handling corrupted files is to
use the backup files VP creates upon opening each project. The backup files all have extensions that
begin with an ~ so that backed-up .db files look like .~db files and the backed-up List files look like
.~ls files. These files contain the last used values but not your most recent changes. Something like
Windows Explorer can be used to manually rename the files.
Substitute backup file commands
CA UTION: The ambient file substitution command on the Edit menu only works for the first
file in the ambient file list.
Quitting VP to force variables to be reinitialized
VP is a substantial program; it is difficulty to foresee all the problems that users will sooner
or later encounter. Sometimes you may get errors you don't understand, some of which may mean
that some variable has not been reinitialized. Under these circumstances, try exiting VP and
re-starting it. If you think the problem is important to you, please contact one of the authors.
Models do not run when the tables show ] [ in the row pointer
The diffuser and ambient tables must show the row pointer (>•) before the models will run.
Values do not changed when a new unit is selected
Make sure the Convert data option is selected on the Units Conversion radio group.
Wrong ambient file shown in text output
8.3
-------
This can happen when multiple ambient files are listed on the Ambient file list and the
Sequential, all ambient list option is selected on the Case selection radio group. Be sure that the row
pointer (>•) points to the base case before beginning the run.
8.2.3 Hints
Direct access files
VP's db files are direct access files, changes are permanent. On exiting, when the Pre-exit:
File Editing Dialogue Window appears all files have been closed and may be manipulated as files.
File filters
The Pre-exit: File Editing Dialogue Window has filters to help with the disposal of unwanted
files in the Files of type pull-down edit box. The files displayed in the window can be changed to
reflect filtering. Care should be taken when selecting the files for deletions.
Froude number, model parameters
The Parameters/or selected row must be pushed to update the first three rows of information
on this panel. For the action to work the Base or selected case option must be selected on the Case
seletion radio group and the row pointer (>•) must be showing on the selected row.
Reestablish backup file by saving
VP makes backup files upon opening a project. Sometimes it is a good idea to quit VP and
restart just before making exploratory changes, this way desirable changes can be reestablished by
substituting the back up files if the exploratory changes do not work out.
Tidal buildup capability
Remember to adjust the coast bin when changing the segment length.
Creating VAR files
When running DOS PLUMES from VP, VP can only define the independent variables, it
does not provide dependent variables (white in DOS PLUMES), the stop criterion, output table
variables, and other DOS PLUMES settings.
8.2.3 Known or suspected bugs
Far-field dilution not graphed to the end of the simulation
8.4
-------
This problem appears to be corrected by quitting VP and restarting.
Graphics panel and Style button disagree
This is fixed by selecting the desired Style button again.
Mancini model usage
Be sure that Measurement depth or height unit is returned to m before running the models.
To change the unit, double click on the blue cell to put it into the change mode, then click again and
change the unit. Also, remember that in general VP does a conversion to decay rate unit s-1 (per
second) when the models are run. Only UM3 uses the Mancini model in a dynamic sense. See
Section 6.5.1.
8.5
-------
-------
9 Extended Bibliography
9.1 Selected references
Davis, L.R., 1999. Fundamentals of environmental discharge modeling. CRC Press, Baton Raton,
FL.
Fergen, R.E., H. Huang, and J.R. Proni, 1994. Comparison of SEFLOEII field initial dilution data
with two EPA models: UM and CORMIX. WEFTEC '94, Chicago, IL.
Frick, W.E., DJ. Baumgartner, L.R. Davis, W.S. Lung, and P.J.W. Roberts, 2000. Modeling
consistency, model quality, and fostering continued improvement. Proceedings of Marine Waste
Water Discharges 2000. Genoa, Italy, 28 Nov to 1 Dec, 2000.
Frick, W., A. Sigleo, S. Emerman, and J. Keyes, 1999. An innovative theory of turbulence. A
Power-Point presentation forming the basis for a presentation to the Estuarine Research Federation
Meeting, New Orleans, LA, September 1999. This slide show gives the user a broad understanding
of turbulence and its relationship to entrainment; in file: WF99436b.ppt.
Keyes, J., W. Frick, and A. Dufour, 1999. "A Case Study Using the EPAs Water Quality Modeling
System, the Windows Interface for Simulating Plumes (WISP)." Hydrology Days (1999) conference,
Colorado State Univ., Ft. Collins, CO.
This work presents a tour of VP capabilities, including an application of the
time-series capability and the Mancini bacterial decay model. In file: paper.wpd,
Keyes, J., 1999. A case study using the EPAs water quality modeling system, the Windows Interface
for Simulating Plumes. A Power-Point presentation expanding on the materials covered in Keyes
et al., 1999 (above); in file: Presentation2.ppt.
Mancini, J.L., 1978. Numerical estimates of coliform mortality rates under various conditions.
Journal of the Water Pollution Control Federation, Nov 1978, pp. 2477-2484.
Massachusetts Water Resources Authority (MWRA), 2000. What about the new outfall?
http://www.mwra.state.ma.us/harbor/html/outfall_update.htm
Roberts, P.J.W., 2000. Experiments providing information on plume peak-to-mean ratios. Personal
communication.
9.1
-------
9.2 Extended bibliography
The bibliography found in the DOS PLUMES manual is reproduced here.
Akar P. J. and G.H. Jirka, July 1990. CORMIX2: An expert system for hydrodynamic mixing zone
analysis of conventional and toxic multiport diffuser discharges. EPA/600/3-91/073, ERL, Office
of Research and Development, USEPA, Athens, GA 30613.
Albertson, M.L., Y.B. Dai, R.A. Jensen, and H. Rouse, 1948. Diffusion of submerged jets.
Transactions of the American Society of Civil Engineers, pp 1571-1596.
Anon., 1982. Code of Federal Regulations. Parts 122 and 125. Modifications of secondary
treatment requirements for discharge into marine waters. Federal Register. Vol 47, No. 228. pp
53666-85. (November 26, 1982).
Anon., 1983. Clean water act amendments of 1983. Report of the committee on environment and
public works, United States Senate. Report No. 98-233. September 21, 1983. U. S. Government
Printing Office. Washington.
Anon., 1987. Water quality act of 1987, Public Law 100-4, February 4, 1987. Congress of the
United States. U. S. Government Printing Office. Washington.
APHA, 1975. Standard methods for the examination of water and wastewater. 14th Edition.
American Public Health Association. Washington. 1193 pp.
Baker, E.T., J.W. Lavelle, R.A. Feely, G.J. Massoth, and S.L. Walker, 1989. Episodic venting of
hydrothermal fluids from the Juan de Fuca Ridge. Journal of Geophysical Research.
Baumgartner, D., W. Frick, P. Roberts. 1994. Dilution Models for Effluent Discharges (3rd Ed).
EPA/600/R-94/086, U.S. Environmental Protection Agency, Pacific Ecosystems Branch, Newport,
Oregon.
Baumgartner, D.J., W.E. Frick, W.P. Muellenhoff, and A.M. Soldate, Jr., 1986. Coastal outfall
modeling: status and needs. Proceedings Water Pollution Control Federation 59th Annual
Conference. Los Angeles, CA. (October 7, 1986).
Baumgartner, D.J., and D.S. Trent, 1970. Ocean outfall design Part I, literature review and
theoretical development. NTIS No. PB 203-749. (April 1970).
Behlke, C.E. andF.J. Burgess, 1964. Comprehensive study on ocean outfall diffusers. Oregon State
University, Engineering Experiment Station, Department of Civil Engineering. 26pp. May 1,1964.
Bodeen, C.A., T.J. Hendricks, W.E. Frick, D.J. Baumgartner, J.E. Yerxa, and A. Steele, 1989.
User's guide for SEDDEP: a program for computing seabed deposition rates of outfall particulates
9.2
-------
in coastal marine environments. EPA Report 109-ERL-N. Environmental Protection Agency,
Newport, OR 97365. 79 pp.
Brater, E.F. and H.W. King, 1976. Handbook of hydraulics for the solutions of hydraulic
engineering problems, Sixth Edition. McGraw-Hill, NY.
Brooks, N.H., 1956. Methods of analysis of the performance of ocean outfall diffusers with
application to the proposed Hyperion outfall. Report to Hyperion Engineers, Los Angeles California
(April 5, 1956).
Brooks, N.H., 1960. Diffusion of sewage effluent in an ocean current, pp 246-267. Proceedings
of the First Conference on Waste Disposal in the Marine Environment. Ed. E. A. Pearson. Pergamon
Press. New York. 569 pp.
Brooks, N.H., 1973. Dispersion in hydrologic and coastal environments. EPA-660/3-73-010.
(August 1973).
Carhart, R.A., AJ. Policastro, S. Ziemer, S. Haake, and W. Dunn, 1981. Studies of mathematical
models for characterizing plume and drift behavior from cooling towers, Vol. 2: mathematical model
for single-source (single-tower) cooling tower plume dispersion. Electric Power Research Institute,
CS-1683, Vol. 2, Research Project 906-01.
Carhart, R.A., AJ. Policastro and S. Ziemer, 1982. Evaluation of mathematical models for
natural-draft cooling-tower plume dispersion. Atmospheric Environment, Vol 16, pp. 67-83.
Carr, V.E., W.D. Watkins, and J.F. Musselman, 1985. Ocean Outfall Study, Morro Bay California.
Report to Region IX Shellfish Specialist. Northeast Technical Services Unit. Davisville, R.I. U.S.
Department of Health and Human Services. 74 pp.
Callaway, RJ. 1971. Application of some numerical models to Pacific Northwest estuaries, pp
29-91. Proceedings Technical Conference on Estuaries in the Pacific Northwest. Oregon State
University, Engineering Experiment Station Circular 42. (March 19, 1971).
Cheung, V., 1991. Mixing of a round buoyant jet in a current. Ph.D. Thesis, Dept. of Civil and
Structural Engineering, University of Hong Kong, Hong Kong.
Davis, L.R., 1999. Fundamentals of Environmental Discharge Modeling. CRC Press, Boca Raton,
FL.
Davis, L.R. and E.Hsiao, 1991. An experimental/analytical investigation of buoyant jets in shallow
water. Oregon State University, Corvallis OR.
9.3
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Doneker, R.L. and G.H. Jirka, 1990. Expert system for hydrodynamic mixing zone analysis of
conventional and toxic submerged single port discharges (CORMIX1). EPA/600/3-90/012, ERL,
Office of Research and Development, USEPA, Athens, GA 30613.
Fan, L.N., 1967. Turbulent buoyant jets into stratified or flowing ambient fluids. Report No.
KH-R-15, W.M. KeckLab. ofHydraulics and Water Resources, California Institute of Technology,
Pasadena, California.
Fischer, H.B., EJ. List, R.C.Y. Koh, J. Imberger, and N. H. Brooks, 1979. Mixing in inland and
coastal waters. Academic Press. New York. 483 pp.
Frick, W.E., DJ. Baumgartner, and C.G. Fox, 1994. Improved prediction of bending plumes.
Journal of Hydraulic Research, Vol. 32, No. 6, pp. 935-950.
Frick, W., C. Sproul, and D. Stuart. 1997. Bacterial Impacts of Ocean Outfalls: Legal Challenges.
Journal of Environmental Engineering, Vol. 123, No. 2, February, 1997.
Frick, W.E., C.G. Fox, andD.J. Baumgartner, 1991. Plume definition in regions of strong bending.
Proceedings of the International Symposium of Environmental Hydraulics (December 16-18,1991).
Frick, W.E., C.A. Bodeen, D.J. Baumgartner, and C.G. Fox, 1990. Empirical energy transfer
function for dynamically collapsing plumes. Proceedings of International Conference on Physical
Modeling of Transport and Dispersion, MIT, (August 7-10, 1990).
Frick, W.E., 1984. Non-empirical closure of the plume equations. Atmospheric Environment, Vol.
18, No. 4, pp. 653-662.
Frick, W.E., 1981. A theory and users' guide for the plume model MERGE, revised, Tetra Tech Inc.,
Environmental Research Laboratory, Corvallis, OR.
Frick, W.E. and L.D. Winiarski, 1978. Why Froude number replication does not necessarily ensure
modeling similarity. Proceedings of the Second Conference on Waste Heat Management and
Utilization. Dept. of Mechanical Engrg., Univ. of Miami (December 4-6, 1978).
Frick, W.E. and L.D. Winiarski, 1975. Comments on "The rise of moist buoyant plumes". J. of
Applied Meteorology, Vol. 14, p. 421.
Grace, R.A., 1978. Marine Outfall Systems. Prentice-Hall. Englewood Cliffs. 600 pp.
Gremse, F., 1980. Transmittal of the DPHYDR program. Personal communication.
Hendricks, T.J., 1983. Numerical model of sediment quality near an ocean outfall. NOAA Final
Report on Grant # NA8ORAD00041. Seattle, WA.
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Hendricks, T., 1982. An advanced sediment quality model. Biennial Report for the years 1981-82.
SCCWRP. Long Beach, CA. pp 247-257.
Hoult D.P., J.A. Fay, and LJ. Forney, 1969. A theory of plume rise compared with field
observations. J. of Air Pollution Control Association, Vol 19, pp. 585-589.
Hunt, J., 1990. Particle Removal by coagulation and settling from a waste plume. Oceanic
Processes in Marine Pollution, Vol. 6. Physical and Chemical Processes: Transport and
Transformation. Eds. DJ. Baumgartner and I.W. Duedall. Krieger Publishing Co. Malabar Florida.
248 pp.
Isaacson, M.S., R.C.Y. Koh, andN.H. Brooks, 1978. Sectional hydraulic modeling study of plume
behavior: San Francisco Southwest Ocean Outfall Project. W.M. Keck Laboratory of Hydraulics
and Water Resources, California Institute of Technology, Technical Memorandum 78-2.
Isaacson, M.S., R.C.Y. Koh, and N.H. Brooks, 1983. Plume dilution for diffusers with multiple
risers. Journal of Hydraulic Engineering, ASCE, Vol. 109, No. 2, pp 199-220.
Jirka, G., 1992. Review comments of "Dilution models for effluent discharges (draft)."
Jirka, G. and S.W. Hinton, 1992. User's guide for the Cornell mixing zone expert system
(CORMIX). National Council of the Paper Industry for Air and Stream Improvement, Inc..
Technical Bulletin No. 624. February, 1992.
Jones, G.R., 1990. "CORMIX3: An expert system for the analysis and prediction of buoyant surface
discharges" Masters Thesis, Cornell University.
Kannberg, L.D. andL.R. Davis, 1976. An experimental/analytical investigation of deep submerged
multiple buoyant] ets. USEP A Ecological Research Series, EP A-600/3 -76-101, USEP A, Corvallis,
OR.
Koestler, A., 1964. The act of creation. Macmillan Company, New York, NY.
Lee, J.H.W., 1992. Private communication. Letter of 24 Nov 1992.
Lee, J.H.W. and V. Cheung, 1990. Generalized Lagrangian model for buoyant jets in current.
ASCE J. of Environmental Engineering, Vol. 116, No. 6, pp. 1085-1106.
Lee, J.H.W., Y.K. Cheung, and V. Cheung, 1987. Mathematical modelling of a round buoyant jet
in a current: an assessment. Proceedings of International Symposium on River Pollution Control
and Management, Shanghai, China, Oct 1987.
Ludwig, R. 1988. Environmental Impact Assessment: Siting andDesign of Submarine Outfalls. EIA
Guidance Document (1988). MARC Report Number 43.
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Mancini, J., 1978. Numerical estimates of coliform mortality rates under various conditions. Journal
of Water Pollution Control Federation. November 1978.
Martin, J.L. and S.C. McCutcheon, 1999, Hydrodynamic and transport for water quality modeling,
Lewis Publ, Boca Raton, FL
Menzie, C. A. and Associates, 1986. Technical Information and Research needs to Support A
National Estuarine Research Strategy. Battelle Contract No. 68-01-6986 Final Report to EPA.
Various Paging. (January 1986).
Morton, B.R., G.I. Taylor, and J.S. Turner, 1956. Turbulent gravitational convection from
maintained and instantaneous sources. Proceedings of the Royal Society of London. A234:pp 1-23.
Morton, B.R., 1959. Forced plumes. Journal of Fluid Mechanics. 5: pp 151-197.
Muellenhoff, W.P., A.M. Soldate, Jr., D.J. Baumgartner, M.D. Schuldt, L.R. Davis, and W.E. Frick,
1985. Initial mixing characteristics of municipal ocean outfall discharges: Volume 1. Procedures
and Applications. EPA/600/3-85/073a. (November 1985).
National Research Council (NRC), 1984. Ocean disposal systems for sewage sludge and effluent.
Washington, DC. National Academy Press, 126pp.
Okubo, A., 1962. A review of theoretical models of turbulent diffusion in the sea. Chesapeake Bay
Institute, The Johns Hopkins Univ., Tech Report 30, Reference 62-20.
Ozretich, R.J. and D.J. Baumgartner, 1990. The utility of buoyant plume models in predicting the
initial dilution of drilling fluids. Oceanic Processes in Marine Pollution, Vol. 6. Physical and
Chemical Processes: Transport and Transformation. Eds. D. J. Baumgartner and I.W. Duedall.
Krieger Publishing Co. Malabar Florida. 248 pp.
Policastro, A. J., R. A. Carhart, S.E. Ziemer, andK. Haake, 1980. Evaluation of mathematical models
for characterizing plume behavior from cooling towers, dispersion from single and multiple source
draft cooling towers. U.S. Nuclear Regulatory Commission Report NUREG/CR-1581 (Vol. 1).
Pomeroy, R., 1960. The empirical approach for determining the required length of an ocean outfall.
pp 268-278. Proceedings of the First Conference on Waste Disposal in the Marine Environment.
Ed. E. A. Pearson. Pergamon Press. New York. 569 pp.
Rawn, A.M., F.R. Bowerman, and N.H. Brooks, 1960. Diffusers for disposal of sewage in sea
water. Proceedings of the American Society of Civil Engineers, Journal of the Sanitary Engineering
Division. 86: pp 65-105.
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Roberts, P.J.W., 1977. Dispersion of buoyant waste water discharged from outfall diffusers of finite
length. W. M. Keck Laboratory of Hydraulics and Water Resources, California Institute of
Technology. Pasadena CA. (Report #KH-R-35).
Roberts, P.J.W., 1989. Dilution Hydraulic Model Study of the Boston Wastewater Outfall. Report
Number SCEGIT 89-101, School of Civil Engineering, Georgia Institute of Technology.
Roberts, P.J.W., W.H. Snyder, and DJ. Baumgartner, 1989 a. Ocean outfalls I: submerged
wastefi eld formation. ASCE Journal of Hydraulic Engineering. 115. No. 1. pp 1-25.
Roberts, P.J.W., W.H. Snyder, and DJ. Baumgartner, 1989 b. Ocean outfalls II: spatial evolution
of submerged wastefield. ASCE Journal of Hydraulic Engineering. 115. No. 1. pp 26-48.
Roberts, P.J.W., W.H. Snyder, and DJ. Baumgartner, 1989 c. Ocean outfalls III: effect of diffuser
design on submerged wastefi eld. ASCE Journal of the Hydraulic Engineering. 115. No. l.pp 49-70.
Roberts, P.J.W., 1990. Outfall design considerations. The Sea. Ocean Engineering Science. Vol
9. Eds. B. LeMehaute and D. M. Hanes. Wiley and Sons. New York, pp 661-689.
Roberts, P.J.W., 1991. Basic language RSB program. Personal communication.
Roberts, P.J.W., 1993. "Hydraulic Model Study for the Boston Outfall. I: Riser Configuration,"
To be published in Journal of Hydraulic Engineering.
Schatzmann M., 1979. An integral model of plume rise. Atmospheric Environment, Vol. 13, pp.
721-731.
Spiegel, E.A. and G. Veronis, 1960. On the Boussinesq approximation for a compressible fluid.
Astrophys. J., 131, pp 442-447.
State Water Resources Control Board, 1988. Water Quality Control Plan for Ocean Waters of
California, California Ocean Plan, Sacramento. (September 22, 1988).
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discharges. CERL Publ. 043, 90 pp. U. S. Environmental Protection Agency Environmental
Research Laboratory, Corvallis, Oregon.
Tetra Tech, 1980. Technical evaluation of Sand Island wastewater treatment plant section 301(h)
application for modification of secondary treatment requirements for discharge into marine waters.
Prepared for U.S. EPA, Washington, D.C..
Tetra Tech, 1982. Revised Section 301(h) Technical Support Document. Prepared for U. S.
Environmental Protection Agency. EPA 430/9-82-011. (November 1982).
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Tetra Tech, 1984. Technical review of the Sand Island wastewater treatment plant section 301(h)
application for modification of secondary treatment requirements for discharge into marine waters.
Prepared by Tetra Tech, Inc.
Tetra Tech, 1987. A simplified deposition calculation (DECAL) for organic accumulation near
marine outfalls. Prepared for USEPA. Washington, D.C.
Turner D.B., 1970. Workbook of atmospheric dispersion estimates. Office of Air Programs
Publication No. AP-26. USEPA, Research Triangle Park, North Carolina.
U. S. Environmental Protection Agency, 1982. Revised Section 301(h) Technical Support
Document. EPA 430/9-82-011. (November 1982)
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1986).
Ward, G.H. Jr., and W.H. Espey Jr., Eds., 1971. Estuarine Modeling: An Assessment. Capabilities
and Limitations for Resource Management and Pollution Control. EPA Water Pollution Control
Research Series. 16070 DZV 02/71. 497pp. February, 1971.
Weast, R.C., 1978. CRC Handbook of Chemistry and Physics. CRC Press, Inc., Cleveland, OH
44128.
Weil J.C., 1974. The rise of moist buoyant plumes. Journal of Applied Meteorology, Vol. 13, No.
4.
Winiarski, L.D. and W.E. Frick, 1976. Cooling tower plume model. USEPA Ecological Research
Series, EPA-600/3-76-100, USEPA, Corvallis, Oregon.
Winiarski, L.D. and W.E. Frick, 1978. Methods of improving plume models. Presented at Cooling
Tower Environment u 1978. University of Maryland. (May 2-4 1978).
Wood, I.R. and M.J. Davidson, 1990. The merging of buoyant jets in a current. Proceedings of
International Conference on Physical Modeling of Transport and Dispersion, MIT, (August 7-10,
1990).
Wright, S.J., 1984. Buoyant jets in density-stratified crossflow. J. of Hydraulic Engineering., ASCE,
110(5), pp 643-656.
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9.9
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Appendix: Notes and important recent changes
Revised: 6 March 2002, pre-CEAM-release revision 24 July 2001, 30 April 2001
Adapted from the Visual Plumes Readme file.
» Abstract«
Visual Plumes is Windows software for simulating jets and plumes and for assisting in the
preparation of mixing zone analyses, TMDLs, and other water quality applications. This file
contains information to help you install and run Visual Plumes, as well as product news, including
descriptions of recent additions and changes, hints, caveats, and other relevant comments.
» Table of Contents «
Abstract
Introduction
Installation
Filename convention
Project list file
Support
Hints
Limitations
Recent changes
Earlier changes
Troubleshooting
Extra (optional) files
Mixing zone course material: Introduction
Mixing zone course material: Table of contents
Mixing zone course material: Optional folders
Example: Fan-Run-16 (optional exercise)
Another optional example
References
»Introduction «
The Visual Plumes compact disk (CD) or the U.S. EPA Athens web page contains all the
software and documentation necessary to implementthe U. S. EPA Visual Plumes model. The Visual
Plumes setup software is found in the Visual Plumes (VP) Setup folder. For convenience, the latest
executable is also found in a sub-folder called Latest-executable. WordPerfect and PDF versions of
the manual are found in the Visual Plumes Guidance folder.
Visual Plumes has passed peer review, i.e., it has been peer reviewed, the reconciliation process
has been completed, and permission to disseminate Visual Plumes has been granted.
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Events accompanying "small-science" software development make it difficult to synchronize
final versions of both software and the manual. For example, an update of the context-sensitive help
is not available at this writing. The passage of time has given users time to identify problem areas
and to request additions and changes. Consequently, some screen depictions shown in the manual
(and other guidance) are no longer identical to current renditions. The authors apologize for the
problems associated with this situation. It may help to remember that only the senior author is an
EPA employee and most of the other work represents donated time and effort. Users are encouraged
to let EPA know the value of mixing zone modeling software and guidance so that more resources
may be devoted to it in the future.
The instructional material found in the folder entitled "Mixing zone course units" is based on the
California State Water Resources Control Board mixing zone course (February 2000, presented by
Walter Frick and Debra Denton) and subsequent similar courses. These materials are intended as
classroom visual aids, however, they will hopefully also prove useful in an unassisted context.
»Installation «
Visual Plumes must be installed before it will run correctly. The installation software for Visual
Plumes (VP) is found in the Visual Plumes (VP) Setup folder. The filename is Setup.exe. When
installing it is recommended that you adopt the default folders and settings, creating a file folder
called Plumes. When done, the VP executable, Plumes.exe, will be found in that folder. The name
Plumes continues the DOS tradition. The executable can be renamed, for example, you might call
it VP.exe. For updates normally only Plumes.exe will need to be replaced.
It is recommended that you contact me, the senior author, for the latest compile as the web
version ofPlumes.exe is updated relatively infrequently. Send email to frick.walter@epa.gov
Test run Plumes.exe. If you have problems it may be necessary to first change the Windows
properties of the files. That is, before you access the example files you may have to first deselect
their 'read only' property: in Windows Explorer, select all the project files (the project database files
with extension .db, and project list files with extension .1st) and then right click: select Properties,
and click off the Read-only option.
» Filename convention «
Be aware of the new naming convention. For the main project file (which stores the diffuser
table), it is the project name followed by .vpp.db, for example, MD-Pathogen.vpp.db (project name:
MD-Pathogen, followed by project marker: .vpp, followed by database file extension: .db). There
should be no periods in the project name itself. When opening a project from within VP, VP will
only show the project names in the dialog box.
The ambient files follow a similar format, a project name followed by .XXX.db, where XXX is
a numeric sequence like 001, 002, etc., for example, MD-Pathogen. 00 l.db or
Winter-such-and-such.OlO.db. Note there can be many ambient files and, internally, a project might
refer to ambient files from other projects. (Spaces are not recommended in the file name.)
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» Project List file «
Visual Plumes creates and maintains project "list" files. List files record many (but not all)
customized settings. The list filename format is the proj ect name followed by .1st, for example, MD-
Pathogen.lst. (For advanced users, the time-series files follow a similar format.)
» Support«
After trying VP, you may wish to call me at 706/355-8319 for a short phone tutorial. If you are
doing official work you are always welcome to let me know so that I can provide the latest version
ofVP.
Let me know if you have questions. (Email: frick.walter@epa.gov).
» Hints «
In the ambient tab input table: to extrapolate below a pair of ambient data points an additional
line reflecting deeper depths should be appended, even if depth is the only value on the line. This
makes the appropriate changes to the ambient input table on the Text tab and stratification profile
on the Graphics tab. A brief troubleshooting section is found in the manual.
» Limitations «
Important: In the usual depth mode, a surface (zero depth, 0) line must be specified in the
ambient table. Without this line the ambient array is not set up correctly.
One user reported that VP does not run DKHW (and presumably other models) when installed
in the E: partition. The same problem occurs when VP is installed as a subdirectory, as for example,
to Program Files.
» Recent changes «
6 March 2002
* 20 Feb 2002: fixed a bug that prevented VP from updating the ambient profile when running
multiple NRFIELD runs.
* 7 Feb 2002: fixed a bug that prevented proper plotting of density profile on the 4-panel graphics
tab. Fixed ambient-table bug affecting interpolation of far-field velocity.
* 23 Jan 2002: fixed bug that resulting in the incorrect depth being passed to NRFIELD.
* 29 Nov 2002: fixed failure to graphic initial DKHW run when running multiple cases.
* 14 Ang 2002: fixed file opening bug when running NRFIELD.
* Date uncertain: fixed far-field algorithm bug resulting in incorrect concentrations when running
in the constant-eddy-diffusivity mode.
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The special settings tab now offers two equations of state, the new one being a function of pressure
as well as salinity and temperature (Text output settings panel). There is also a button to explicitly
select the farf-field diffusivity option (Additional model input panel).
Previous changes
* Additional controls on display of the input tables on the Text tab are found on the Special settings
tab. The ambient table is now echoed at run time. Display can show the tables filled in or show only
those numbers explicitly entered in the tables. The latter option makes the differences between runs
more apparent. This selection is not recorded in the List file.
* UM3 includes a new output criterion, the "matched energy radial velocity]" message. For a plume
in shallow water in which the radius becomes greater than the depth of the element, UM3 computes
the depth and velocity at which the sum of the kinetic and potential energies in the plume element
correspond to the total energy of flow out of an annulus (a cylinder with a vertical axis) surrounding
the element. An experimental program is being developed to estimate additional dilution attained
in the spreading region around plumes discharged vertical into shallow water (as, for example, large
thermal discharges). For more information, call (see Support).
* VP now does a better job creating DOS PLUMES VAR files. The biggest problem revolves
around translating VP's three-dimensional input into DP's 2-D input. Fidelity between the two
inputs is not always easy to establish because UM and UM3 are substantially different models.
However, RSB output should still be identical. New users wishing to run DOS PLUMES should
consult the DOS PLUMES guidance bundled with VP.
* Corrected is a serious bug in the far-field 4/3-power-law solution.
* VP now supports three graphics series: red, blue, and green. (Also, black for verification).
* An exit-without-saving option has been added to the File menu.
* VP now maintains a list of previously accessed projects on the File menu.
* VP maintains more information in the list file, e.g., the graphics tick increment is now maintained.
» Earlier changes «
These changes were made after the WA and OR mixing zone courses, Dec 2000, but before April
2001.
* The farfield increment is now on the Special Settings tab, use it to control the number of
intermediate steps between the acute and chronic mixing zone distances.
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* Input for the UM3 Taylor (aspiration) entrainment coefficient has been added to the Special
Settings tab.
* The second ordinate has been enabled on the Custom-graph-coords radio control box on the
Special Settings tab. This allows output to a second y-axis on the Graphics tab (custom graphic).
Control over the right axis is different from the other graphics settings. Instead of double-clicking
in the margins of the graphics panel, the Right-axis settings button on the custom graphic is used to
reveal the control panel for this axis (see next comment).
* The Right-axis-settings button on the custom graph panel of the Graphics tab may be used to
create the right axis and control the corresponding settings and values. When struck, the settings
panel becomes visible. When satisfied with the settings, click the Show right axis radio button and
strike the Apply settings button to show the right axis plots. The variable plotted is specified on the
Special Settings tab (see previous comment).
* As part of our effort to provide a common platform for several competing models to help
researchers refine their products and to make it easier to compare models both between them and
with verification, a "verification" capability has been added to VP. An example is available in the
files associated with the Fan-Run-16 project, including the Fanl6.txt verification data file. For
further information see the note in the project's memo pad when running this example.
Verification in x-y format can now be superimposed on Visual Plumes predictions on the Graphics
tab. Clicking the "Verify" button gives access to ASCII input file. An example of file input data
excerpted from the example Fanl6.txt file is:
side view
0.0001 1.0145
0.0068 1.0157
0.0149 1.0158
0.0197 1.0161
0.0264 1.0159
density profile
17.3 0.0
25.2 1.0
Blank lines will cause a space between data. The key words (side, profile, path, dilution,
effdilution, concentration, and generic) will shift plotting to the corresponding graphic panel,
namely, the elevation, density profile, plan view, and dilution on the four-panel graphs, and dilution,
concentration, and the generic custom panels. Units should correspond to the ones chosen in Visual
Plumes.
* A clear graphics button has been added to the Graphics tab to allow verification data to be cleared
from the graphics panels.
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* The "Thick" button on the Graphics tab increases the thickness of the solid lines when increased
legibility is needed.
» Troubleshooting «
Sometimes users encounter problems. When those problems can be clearly linked to a cause the
necessary changes are made to prevent the problem in the future. However, some file handling and
initialization problems are difficult to identify or may be system specific.
Try to remember to Exit without saving when encountering a serious problem. This can protect
important work. Then back up important project files before experimenting further.
A remedy that sometimes works is to exit VP and restart. If that still does not work the offending
files can sometimes be reconditioned using the reset commands on the Edit menu or the right-click
options on the diffuser and ambient data tables. If that does not work the project files should be
replaced by backup files and the VPSETUP file might be erased before restarting VP. Please help
us improve VP by contacting us about problems (Walter Frick, 706-355-8319 or
frick.walter@epa.gov).
» Extra (optional) files «
Visual Plumes software includes many peripheral files that are not typically pertinent to the user.
Noteworthy in this regard are many graphics files, for example, encapsulated postscript files with
the EPS extension. For example, the DOS-PLUMES folder has a Original Files folder containing
a file called FBF93G8.eps. This is Figure 8 from Frick, Baumgartner, and Fox, 1994, showing the
difference between UM model predictions with and without correction for the negative volume
anomaly (relating to the "overlap" message sometimes encountered in running DOS PLUMES). It
may viewed in an application like GSview32.exe Version 3.4 (copyright 1993-2000, Ghostgum
Software Pty Ltd. Files with the PLT extension are Hewlett-Packard graphical language files that
may be accessed by special purpose applications like AutoCAD (copyright). Such programs have
usage requirements and idiosyncracies too numerous to list.
Users may peruse these files when wishing to use graphics used in Visual Plumes. In general, the
pertinent files are linked to the guidance files and have little other value.
» Mixing zone course material: Introduction «
The instructional materials are concentrated in PowerPoint presentations in the "Mixing zone
course units" folder and are roughly listed in introductory to advanced categories by the "Al"
through " A9" prefixes. For those users who do not have access to PowerPoint, a viewer is found in
the "A Powerpoint Viewer" folder.
VP software and documentation is contained in the "Visual Plumes (VP) Setup" and "Visual
Plumes Guidance" folders. WordPerfect and PDF versions of the draft manual may be found in the
"VP Manual" folder of the "Visual Plumes Guidance" folder.
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» Mixing zone course material: Table of contents «
MZ1 Introduction:
mzintro-Dec 2000.ppt: a general introduction to plumes (and mixing zone analysis)
Other material includes zipped copies of graphics.
MZ2 Fischer-et-al: (graphics reproduced courtesy of Academic Press)
Fischer-et-al.ppt: site and environmental complexities, model uncertainty, more on siting
MZ3 JennKeyes:
KeyesHydDays.ppt: Jennifer Keyes' Hydrology Days 1999 VP presentation
(A good look at VP capability but many changes to VP since then)
jenngraf.wpd: tide movement for 2 fresh water flows illustrating problem of recirculation
paper2wf.wpd: Keyes, Frick, and Dufour paper published in Hyd. Days 1999
proceedings
MZ4 Lagrange:
Lagmodels-21Sep2001.ppt: Look at a big outfall, general plume behavior, data stuff,
Lagrangian model
Lagmodels2.ppt: model complementarity and comparison, verification, plume element,
gravitational collapse, 3-D model
PhilBoston outfall turret design work, experimental visualization
Shallow Water Capability.ppt: DOE course slides illustrating very-shallow-water capability
Liseth graphics files showing cross-diffuser attraction
MZ5 Winiarski:
lagdensity.ppt: the very important topic of nascent density
WinFrick.ppt: Lagrangian Plume Modeling 101. Plume element, dynamics, time stepping
MZ6 HydroQual Wu
HydroWu.ppt: graphics from a bigger project, a good example
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MZ7 Class-Notes
VP-Tips.ppt
MZ8 Diverse-Issues
Material from the 2001 Alaska mixing zone course; Phil Roberts verification and papers;
material on tides
MZ9 Verification
Verification.ppt
ModelTestsMemo01.pdf: thermal discharge verification data
MZX Walter-etc
Chapman.ppt: critical tide factors
Roy w.ppt: Circulation model capabilities courtesy of Roy Walters
Such models could help determine beach impacts
» Mixing zone course material: Optional Folders «
DOS-PLUMES
Contains DOS manual (3rd Edition) and software (background reference for VP)
Optional-Presentations
HydrologyDays2001Parta.ppt: Part 1 of a poster presented at AGU Hydrology Days 2001,
Colorado State Univ, 2-5 April 2001. Compressible flow and turbulence theory
inspired by the concept of entrainment into plumes.
HydrologyDays2001Partb.ppt: Part 2 of a poster presented at AGU Hydrology Days 2001,
Colorado State Univ, 2-5 April 2001.
plumemovie.ppt: excellent LIF movie courtesy of Phil Roberts
Note: if click does not animate, avi movie files may need to be re-linked
VisualB&P.ppt: A poster describing Visual Plumes and Visual Beach (under development),
prepared for EPA, Athens Open House, 27 April 2001.
Walt.ppt: more LIF courtesy of Phil Roberts
Public-domain Powerpoint Viewer
For those who don't have it, a public domain PowerPoint viewer
» Example: Fan-Run-16 (optional exercise) «
One way to get a feeling for new software is to run a prepared example. The Fan-Run-16 project
provides an informative simple example of a Visual Plumes project. To run this example, start
Visual Plumes by clicking (or double clicking) on the Plumes.exe program in Windows Explorer
(or similar platform, or the Plumes icon if the program has been put on the desktop). The first time
it is worthwhile to read the credits window notes.
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If this is the first time Plumes.exe is run, VP will not yet have established a file called VPSETUP,
which contains the name of the last project run in VP. If this file is absent, VP starts with the "How
to proceed..." panel that helps to customize the program tabs. Based on the target model selected,
VP specifies required columns and attaches the chosen model to the yellow and blue model icon.
The headers on the required columns can be seen to change as different models are targeted. (This
does not prevent the user from subsequently selecting other models from the Models menu, however,
the input requirements can change when that is done.)
For this exercise, select the UM3 model and press the Continue button.
VP establishes a new project called "VP Plume 0" (or other number if a project by that name
already exists). There are always at least two data files attached to any given project; the first is
called the project file and has a ".vpp.db" extension and the second is an ambient file that will have
an extension like ".OOl.db".
One of the hardest ideas for new users to get used to is that the "db" files are direct access files,
which means that the files are updated any time a value is entered or modified. This means that a
"Save" option is redundant, the files are constantly being saved. The down side is that sometimes
users make changes they end up not wanting. VP does allow the re-establishment of backup files,
which it creates when it opens a project. One can also exit without saving. For important files, it is
highly recommended that backup files are kept in a separate folder.
This "getting started" exercise is a quick tour of the Fan-Run-16 project. To open it, choose the
"Open project" command from the file menu, navigate to the folder where VP has been installed,
and select and open the "Fan-Run-16.vpp.db" project file.
Take a look at the tab pages by clicking on the tabs at the top. Read the project memo on the
Diffuser tab; to read all of it, click in the memo space and use the arrow keys to navigate. Note one
ambient file is listed in the Ambient file list, the model icon should show "UM3" under it. The "base
case" is specified for running. Input data are listed on the first line of the diffuser table in the middle
of the tab. Since all the required diffuser and ambient data have been specified, pressing the
"Parameters for selected row" button will calculate the (densimetric) Froude number for the case.
Note that columns headed by "n/r" are not required and have not been filled with data. The optional
panel at the bottom contains information for linking time-series files and may be ignored.
Notice that most components have hints on the status bar at the bottom of the screen.
A nice feature about VP is the ability to select units. On the diffuser tab, click on the Effluent
Flow column unit (which should show about 0.000267MLD or million liters per day). A pop-up list
appears. Clicking on one of the selections makes the conversions. The Effluent density(*) column
allows conversions between salinity and density units. The * reminds the user that this is a mixed
units column, essentially there is athree-way relationship between density, salinity, and temperature.
See the manual for more detail.
Establish the graphics page by clicking on the Graphical Output tab. Click on the Style buttons
to get a feel for the available graphics panels; the "cus" option plots variables specified on the
Special Settings tab. For now, select the "4-pl" (four panel option), those are the panels for which
verification data are available.
Click the Verify button at the bottom left and select the Fanl 6.txt verification file from the dialog
window (some navigation may be necessary). The file contains x-y data points (referenced in the
project memo on the diffuser tab) outlining the plume to be simulated on the Plume Elevation panel
and the density stratification on the Ambient Properties panel. The plume outline should now be
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visible, if not, the axes may have to be adjusted. The Help button at the upper left gives basic
instructions on manipulating graphics. The Scale is often useful when scaling graphics for the first
time.
It is useful to bear in mind that many settings were previously customized when this project was
created. VP keeps settings information in the project "list" file, in this case, "Fan-Run-16.1st". If the
settings are changed the more important ones (like axis scales) are updated and maintained in this
file.
Fan Run 16 is a buoyant plume discharged to stagnant, stratified ambient. Its entry angle into the
trapping level (level of neutral buoyancy) causes some of the plume material to penetrate against
the prevailing motion of the plume, which is generally from left to right. Note that depth does not
correspond to the actual depth in the original experiment, in fact, often plume experiments are
inverted. However, the density stratification is faithfully expressed.
Now run UM3 by selecting it from the Models menu or by finding the model icon and clicking
on it or by pressing the u hot key. The predicted plume using the inputted and default
settings appears in red. Notice that UM3 predicts variables in addition to those that have
corresponding verification data available. Also, notice the "diln" and "con" are not very interesting
because the plot only has a single value. These two "summary" graphic panels are intended for
showing the end results of multiple runs.
Go to the diffuser tab and check the Average plume boundary option on the Model Configuration
checklist and run UM3 again. VP now plots an internal plume boundary at which the concentration
matches the average plume element concentration (based on the 3/2 power profile simulation). This
helps illustrate the fact that concentration tends to be greatest at the center of the plume and
"feathers" out to a value that matches the ambient. At the plume boundary it is difficult to
distinguish plume from ambient.
Select the Text Output tab and examine it. Notice that the trapping level is at 89.2cm depth. The
average dilution at maximum rise is 57.8. To add or remove output variables, use the "Text output
settings" panel on the Special Settings tab. For example, the Time variable might be added by
pressing the down-arrow symbol on the Selection List window. The identifier "Time" will then
appear on the Selected Variables list. Click on the word "Time" to add it to the list. Variables may
be removed from the list by toggling the selection again. This is the time for the plume element to
reach the specified point and factors into the decay of some pollutants, like bacteria.
Return to the graphics tab and select Series 2 (blue). VP automatically goes to the diffuser tab,
assuming some input changes are coming or that another case is to be selected to be run. Notice, if
there were multiple cases (like there are in the Astoria project) the solid right-pointing arrow will
indicate the selected case. Simply clicking on a line of data will select the case.
However, right now move to the Special Settings tab and modify the value of the aspiration
coefficient to 0.12. UM3 has only one tuned coefficient and this is it. Generally, a value of 0.1 is
recommended. Note that the status line indicates this value is not updated in the project list file. On
exiting the project the new value will revert back to 0.1.
Run UM3 again. Note the differences in rise and plume position. To view the outer boundary,
the Average plume boundary option on the diffuser tab must be turned off. To avoid clutter, the blue
inner plume symbols might be removed by pressing the Clear 2b button (note that the status bar
explains what is cleared by this button). Now run UM3 again.
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This kind of exercise for many runs might be done to optimize the aspiration coefficient. In this
case it appears that the higher entrainment coefficient possibly better simulates the plume traj ectory.
The 0.1 coefficient has the advantage of usually (but not necessarily always) giving a more
conservative dilution estimate (see lower right dilution panel).
Much more could be done and deduced from this exercise. For example, not much entrainment
occurs beyond the trapping level where the plume element enters the spreading layer. This is quite
different from the DOS Plumes UM prediction because UM3 addresses the "overlap" problem
described in the DOS Plumes manual. The user could try running the other models (except PDS,
which is a surface discharge model, and NKFIELD, which is a multi-port model).
Further experimentation is encouraged. Remember that if a backup folder of the files has not been
made it may be difficult to remember the original contents of the project. A backup folder will help
avoid re-installing VP to recover the original files.
To terminate this session, press the close button at the upper right corner or select Exit from the
File menu. Remember, your diffuser and ambient input data changes have been saved all along.
For polished work the graphics can be substantially customized. Double click in a graphics
margin to bring up the customizing dialog window for each graphic. Axis, titles, fonts, and more can
all be changed, however, remember only the more important settings are maintained in the project
list file.
The To File button can be used to make bitmap copies of the graphics panels (under the same
project name). They can then be further processed in programs like Paint. The 4-panel graphics are
first enlarged before they are saved and are considerably higher quality than the VP graphics.
The plume manual provides a step-by-step tutorial on developing VP project files.
» Another optional exercise «
The "nonlinear-vs-linear" project is interesting in that it illustrates multiple runs and also the
importance of the non-linear equation of state on plume behavior. Linear theory holds that all three
basic runs contained in the file (one for each ambient profile, or file on the ambient list) would give
the same prediction for all eight plume temperatures on the diffuser tab. This is because the cases
have been set up to have the same densimetric Froude number. (Test this by establishing a case on
the diffuser table by clicking on a line, followed by pressing the Parameters for selected case button
in the lower left panel. The Base or selected case on the Case selection radio button box must be
pressed to use the Froude number button. When satisfied, select the "Sequential, all ambient list"
option again.)
It is recommended that both DKHW and UM3 be run with this data (change the plotting color
for the second model). Reveal the dilution graph panel by pressing the "diln" radio button on the
Style box. Notice the wide range of maximum rise dilutions for the three sets of eight cases. On the
other hand, both models predict similarly. This exercise illustrates the potential dangers inherent in
similarity (or length scale) modeling and dimensional analysis when fluids wit non-linear equations
of state are being considered.
The three ambient input files may be viewed by clicking on the corresponding file names on the
ambient file list on either the diffuser or ambient tabs. These files are manipulated through pop up
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menus that appear upon right clicking on the ambient file list on the diffuser tab. More detail is
available in the manual.
» References «
Frick, WE, DJ Baumgartner, and CG Fox, 1994. Improved prediction of bending plumes. Journal
of Hydraulic Research, Vol 32, No 6
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Index
4-panel graphics 2.17
4/3 Power Law 3.4
Add all xxx 2.11
Adding cases 6.3
After run go to tab 2.4
All combinations 2.6, 3.1
Amb(ient) current vector averaging 2.7, 2.13
Ambient file list 2.4, 2.9
Ambient Files 2.5
Ambient tab 2.8, 3.3
Ambient Time-Series Files 5.3
Ambient variables 3.3
Ambient-Inputs panel 2.9
assumptions 4.24, 6.11, 6.35
Average plume boundary 2.4, 2.7
Base or selected case 2.6
blank lines caution (time-series files) 6.16
Borrow time series from project 2.8
Brooks far-field algorithm 1.6, 2.6
bugs 8.5
Case selection 2.4, 2.6
Channel seg. length 2.13
Channel width 2.13
Clear + 2.19
Clear all 2.19
Clear Display 2.16
Coastbin 2.13
Coast concentration 2.13, 6.17
concentration 4.5
Concentration graphic 2.18
Conservative pollutant 6.12
Context-sensitive help 4.9
contraction coefficient 2.13
Convert data 2.6, 3.5
Creating a second ambient input file and table . . 4.19
Creating additional ambient tables 2.11
Creating Ambient tables 3.4
Creating diffuser table time-series files 6.13
Creating new ambient files 6.33
cross-diffuser merging 4.25
Current speed 3.4
currents 6.32
Custom graph 6.9
Custom graph coords 2.15
Custom graphic 2.18
Customized graphics 4.20
Customizing graphics 2.20, 4.17
Database Files 3.5
densimetric Froude number 2.7, 6.3
density 6.4
density stratifcation 4.19
Depth 2.10,5.4
Diffuser tab 2.4, 3.1
Diffuser table 2.4, 2.5, 5.2
Diffuser variables 3.2
Diffuser, Flow, Mixing Zone Inputs 2.4
diffusers 4.1
dilution 4.3
Dilution graphic 2.17
DKHW 1.4
DOS PLUMES 1.5
DOS PLUMES manual 7.4
DP (see DOS PLUMES) 1.5
Edit Menu 2.2
Editing data 6.1
editing the Ambient file list 6.33
effective dilution 2.7, 2.18, 4.3, 4.5
effluent flow input file 6.13
Effluent variables 4.10
Entrainment 4.3, 4.4
EPA contact person 4.7
Exit without saving 4.10
Extrapolation 4.19, 4.22
Extrapolation (btm) 2.10
Extrapolation (sfc) 2.10
Far-field diffusion coefficient 3.4
Far-field output 4.16
Far-field variables 4.15
Farfield increment 2.14, 4.17
File (time-series) selection 2.8
File corruption 8.1
File Menu 2.1
Filename Conventions 3.5
Files 3.5
FRFIELD 1.5
Froude number 2.7, 2.21
Graphics settings panel 2.15
header array 2.10
heat transfer 2.14, 6.25
Height 2.10,5.4
Help Menu 2.2
Hidden components 2.20
Hints 8.4
How to proceed 3.1
input 3.1
input variables 3.2, 3.3, 6.30
Inputting data 4.11
interpreting results 4.21
jets 4.1
Label only 3.5
Label only mode 2.6
langleys/hr 3.4
Light absorption coefficient 2.14
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linear_to_zero 2.10
Linking time-series files 5.1
Mancini model 6.22, 6.34, 8.5
Mass conservation 6.11
Max detailed graphs 2.15
max dilution reached 4.14
max vertical reversals 2.14
Maximum dilution reported 2.14
Measurement depth 3.3
Merging 4.25
mixing zone 3.2, 4.2, 4.10
Mixing zone boundaries 4.6
Mixing zone depth 2.13
MKS units 3.1
Model configuration 2.4, 2.6, 2.15
Models Menu 2.2
Multi-port discharge 4.24
Multiple runs 6.5
nascent density 6.4, 7.1
NRFIELD 1.5, 2.15
Oil well diffuser 6.2
Outfalls 4.1
output format 2.15
Output medium 2.14
output steps 2.14
Outputto file 2.19
output variables 4.15
pan 6.35
parameters 6.3
Parameters for selected row 2.21
Parameters for selected row panel 2.5, 2.7
Partnership 4.24
pathogen 6.20
PDSW 1.4,2.14,6.25
peak-to-mean ratio 4.23
plume element 4.3
plumes 4.1
Pollutant decay rate 3.4, 6.20
Pollutant solar rad(iation) 3.4
Printing graphics 2.20
Project files 3.5
Project memo box 2.4
Reset ambient headers 3.5
Reset diffuser headers 3.5
restoring initial ambient table data 2.11
reversals 2.14
Running multiple cases 6.38
Running the models 4.13, 6.7
Save ambient file as 2.11
Scale 2.19
Selected Variables 2.14
Sequential, parse ambient 6.5
Series 2.18
SI units 3.1
Special settings 6.17
Special Settings tab 2.11, 2.15
Speed bar buttons 2.2, 2.3
Start case for graphs 2.15
Starting VP 4.7
Stop-Run Menu 2.2
stratification 6.32
Style 2.15
Substitute ambient backup file 2.11
Summary graphics 6.8
surface discharge 6.25
T90hr 3.4
Tab identifiers 4.7
Text output settings 2.14
Text Output tab 2.15
Three-dimensional generalization 7.5
tidal pollutant buildup 2.12
Tidal pollution buildup 2.7, 6.10, 6.17
Tidal pollution buildup option 6.14
Time Series File (optional) panel 2.8
Time series files panel 2.5
Time-series file extensions 5.3
time-series filenames 3.6
time-series files 5.1
Time-series files panel 2.9
Time-series input 2.8
Tips 4.23
To File 2.19
troubleshooting 4.14, 8.1
UM3 1.3, 2.12, 2.14, 6.17, 6.34
UM3 aspiration coefficient 2.14
Unit conversion 2.5, 2.6
units 2.10,3.1
Units conversion 6.2
variables 3.2, 4.10
verification 8.1
Verify button 2.18
Visual Plumes 1.1, 4.8
VP (Visual Plumes) 1.1
water column 2.10
zoom 6.35
Zooming 4.22
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