### September 1996



## USER'S MANUAL FOR CORMIX: A HYDRODYNAMIC MIXING ZONE MODEL AND DECISION SUPPORT SYSTEM FOR POLLUTANT DISCHARGES INTO SURFACE WATERS

by

Gerhard H. Jirka , Robert L. Doneker , and Steven W. Hinton 12 3



### DeFrees Hydraulics Laboratory School of Civil and Environmental Engineering Cornell University Ithaca, New York 14853-3501

now at: Institute for Hydromechanics, University of Karlsruhe 1 Karlsruhe, D-76131, Germany

now at: Ore g on Graduate Institute, PO Box 91000, Portland, OR 97291-1000 2

National Re g istry of Capacity Ri g hts, West Peabody, MA 01960 3

Cooperative A g reement No. CX824847-01-0

Project Officer: Dr. Hiranmay Biswas

OFFICE OF SCIENCE AND TECHNOLOGY U.S. ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, DC 20460ii 

## Abstract

The Cornell Mixin g Zone Expert System hi g hly unsteady environments, such as tidal (CORMIX, Version 3.0 or hi g her) is a software reversal conditions, in which transient system for the analysis, prediction, and desi g n of recirculation and pollutant build-up effects can aqueous toxic or conventional pollutant occur. dischar g es into diverse water bodies. The major emphasis is on the g eometry and dilution In addition, two post-processin g models characteristics of the initial mixin g zone -- are linked to the CORMIX system, but can also be includin g compliance with re g ulatory constraints--, used independently. These are CORJET (the but the system also predicts the behavior of the Cornell Buoyant Jet Inte g ral Model) for the dischar g e plume at lar g er distances. The hi g hly detailed analysis of the near-field behavior of user-interactive CORMIX system is implemented buoyant jets, and FFLOCATR (the Far-Field on microcomputers (IBM-PC, or compatible), and Plume Locator) for the far-field delineation of consists of three inte g rated subsystems: dischar g e plumes in non-uniform river or estuary

---CORMIX1 for submer g ed sin g le port dischar g es, This user's manual g ives a comprehensive ---CORMIX2 for submer g ed multiport diffuser description of the CORMIX system; it provides dischar g es, g uidance for assembly and preparation of ---CORMIX3 for buoyant surface dischar g es. required input data for the three subsystems; it

While CORMIX was ori g inally developed g uidance for interpretation and g raphical display under the assumption of steady ambient of system output; and it illustrates practical conditions, Version 3.0 also allows application to system application throu g h several case studies. environments.

delineates ran g es of applicability; it providesiii 

## Acknowledgments

An earlier version of this user's manual with the United States Environmental Protection coverin g the three separate CORMIX subsystems A g ency. The authors would like to extend their (Version 1.0) before they were inte g rated into a appreciation to Dr. Hiranmay Biswas, Project comprehensive sin g le system was developed Officer, for his g uidance of the project. under s upport form the National Council of the Paper Industry for Air and Stream Improvement Additional support for the development, Inc. (NCASI) and was published as Technical testin g and evaluation of CORMIX system Bulletin No. 624 of NCASI (Jirka and Hinton, elements was provided by the State of Delaware 1992). With the permission of NCASI, that user's D epartment of Natural Resources (Mr. Rick g uide has up until recently also been distributed Greene, Project Officer) durin g 1991, by the by the USEPA-Center for Environmental Austrian Verbund g esellschaft (Dr. Gerhard Assessment Modelin g (CEAM), Athens, GA, as Schiller, Project Officer) durin g 1991/92, and by part of the modelin g support for CORMIX. the State of Maryl and Department of Natural

With the completion of CORMIX Version 1992 to 1995. 3.0 and its many new pro g ram features, the present revision and u pdate of the user's manual Cameron Wilkens, Electronics Technician, has become necessary. This work was in the DeFrees Hydraulics Laboratory, g enerously conducted at the DeFrees Hydraulics Laboratory, assisted with solutions for computer hardware Cornell University, as a Cooperative A g reement and software problems. Resources (Dr. Paul Miller, Project Officer) durin giv 

## Table of Contents

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Metric Conversion Factors for Dimensions Used in CORMIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii

I Introduction ................................................................. 1

II Background: Mixing Processes and Mixing Zone Regulations ............................... 3 2.1 Hydrodynamic Mixin g Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1.1 Near-Field Processes ........................................... 3 2.1.2 Far-Field Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.2 Mixin g Zone Re g ulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.2.1 Le g al Back g round . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.2.2 Mixin g Zone Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.2.3 Special Mixin g Zone Requirements for Toxic Substances . . . . . . . . . . . . . . 13 2.2.4 Current Permittin g Practice on Mixin g Zones . . . . . . . . . . . . . . . . . . . . . . . . 14 2.2.5 Relationship Between Actual Hydrodynamic Processes and Mixin g Zone Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

III General Features of the CORMIX System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.2 Capabilities and Major Assumptions of the Three Subsystems and the Post-Processor Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.2.1 CORMIX Subsystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.2.2 Post-Processor Models CORJET and FFLOCATR . . . . . . . . . . . . . . . . . . . . 18 3.3 System Processin g Sequence and Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.4 CORMIX Data Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.5 Lo g ic Elements of CORMIX: Flow Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.6 Simulation Elements of CORMIX: Flow Prediction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.7 CORMIX Output Features: Desi g n Summary and Iterations . . . . . . . . . . . . . . . . . . . . 21 3.7.1 CORMIX Session Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.7.2 CORMIX1, 2 or 3 Prediction File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.7.3 CMXGRAPH Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.8 Post-Processor Models CORJET and FFLOCATR: Input and Output Features . . . . 23 3.9 Equipment Requirements, System Installation and Run Times . . . . . . . . . . . . . . . . . . 23

IV CORMIX Data Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.1 General Aspects of Interactive Data Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.2 Site/Case Identifier Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.3 Ambient Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 4.3.1 Bounded Cross-Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28v 4.3.2 Unbounded Cross-section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 4.3.3 Tidal Reversin g Ambient Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4.3.4 Ambient Density Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 4.3.5 Wind speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 4.4. Dischar g e Data: CORMIX1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 4.4.1 Dischar g e Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 4.4.2 Port Dischar g e Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 4.5 Dischar g e Data: CORMIX2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 4.5.1 Diffuser Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 4.5.2 Diffuser Dischar g e Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 4.6 Dischar g e Data: CORMIX3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 4.6.1 Dischar g e Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 4.6.2 Dischar g e Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 4.7 Pollutant Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 4.8 Mixin g Zone Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 4.9 Units of Measure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

V CORMIX Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 5.1 Qualitative Output: Flow Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 5.1.1 Descriptive Messa g es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 5.1.2 Len g th Scale Computations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 5.1.3 Description of Flow Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 5.2 Quantitative Output: Numerical Flow Predictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 5.2.1 Summary Output in SUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 5.2.2 Detailed Prediction Output File fn '.CXn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 5.3 Graphical Output: Display and Plottin g of Plume Features Usin g CMXGRAPH . . . . 57 5.3.1 Access to CMXGRAPH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 5.3.2 Use of CMXGRAPH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

VI Post-Processor Models CORJET and FFLOCATR: Input and Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 6.1 CORJET: The Cornell Buoyant Jet Inte g ral Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 6.1.1 General Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 6.1.2 Access to CORJET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 6.1.3 CORJET Input Data File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 6.1.4 CORJET Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6.2 FFLOCATR: The Far-Field Plume Locator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 6.2.1 General Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 6.2.2 Access to FFLOCATR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 6.2.3 FFLOCATR Cumulative Dischar g e Input Data File . . . . . . . . . . . . . . . . . . . . 76 6.2.4 FFLOCATR Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

VII Closure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 7.1 Synopsis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 7.2 System and Documentation Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 7.3 User Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Literature References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Appendix A Flow Classification Diagrams for the Three CORMIX Subsystems . . . . . . . . . . . . . . . 83vi Appendix B CORMIX1: Submerged Single Port Discharge in a Deep Reservoir . . . . . . . . . . . . . . . 93

Appendix C CORMIX1 and 2: Submerged Single Port Discharge and Multiport Diffuser in a Shallow River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Appendix D CORMIX3: Buoyant Surface Discharge In An Estuary . . . . . . . . . . . . . . . . . . . . . . . . . 125

Appendix E Two Applications of CORJET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141vii 

## Glossary Actual Water Depth (HD) - the actual water depth at the submerged discharge location. It is also called local water depth. For surface discharges it is the water depth at the channel entry location.

Alignment Angle (GAMMA) - the angle measured c ounterclockwise from the ambient current direction to the diffuser axis.

Allocated Impact Zone - see mixing zone.

Alternating Diffuser - a multi-port diffuser where the ports do not point in a nearly single horizontal direction.

Ambient Conditions - the geometric and dynamic characteristics of a receiving water body that impact mixing zone processes. These include plan shape, vertical cross sections, bathymetry, ambient velocity, and density distribution.

Ambient Currents - A velocity field within the receiving water which tends to deflect a buoyant jet into the current direction.

Ambient Discharge (QA) - the volumetric flow rate of the receiving water body.

Average Diameter (D0) - the average diameter of the discharge ports or nozzles for a multi-port diffuser.

Average Depth (HA) - the average depth of the receiving water body determined from the equivalent cross sectional area during schematization.

Bottom Slope (SLOPE) - the slope of the bottom that extends from a surface discharge into the receiving water body.

Buoyant Jet - a discharge where turbulent mixing is caused by a combination of initial momentum flux and buoyancy flux. It is also called a forced plume.

Buoyant Spreading Processes - far-field mixing processes which arise due to the buoyant forces caused by the density difference between the mixed flow and the ambient receiving water.

Buoyant Surface Discharge - the release of a positively or neutrally buoyant effluent into a receiving water through a canal, channel, or near-surface pipe.

Coanda Attachment - a dynamic interaction between the effluent plume and the water bottom that results from the entrainment demand of the effluent jet itself and is due to low pressure effects.

Cumulative Discharge - refers to the volumetric flow rate which occurs between the bank/shoreline and a given position within the water body.

Cumulative Discharge Method - an approach for representing transverse plume mixing in river or estuary flow by describing the plume centerline as being fixed on a line of constant cumulative discharge and by relating the plume width in terms of a cumulative discharge increment

Darcy-Weisbach Friction Factor - a measure of the roughness characteristics in a channel.

Deep Conditions - see near-field stability.viii Density Stratification - the presence of a vertical density profile within the receiving water.

Diffuser Length (LD) - The distance between the first and last port of a multi-port diffuser line. See diffuser line.

Diffuser Line - a hypothetical line between the first and last ports of a multi-port diffuser.

Discharge Velocity (U0) - the average velocity of the effluent being discharged from the outfall structure.

Discharge from Shore (DISTB) - the average distance between the outfall location (or diffuser midpoint) and the shoreline. It is also specified as a cumulative ambient discharge divi ded by the product UA times HA.

Distance from Shore (YB1, YB2) - the distance from the shore line to the first and last ports of a multiport diffuser.

Discharge Flow Rate (Q0) - the volumetric flow rate from the discharge structure.

Discharge Channel Width (B0) - the average width of a surface discharging channel.

Discharge Channel Depth (H0) - the average depth of a surface discharging channel.

Discharge Conditions - the geometric and flux characteristics of an outfall installation that effect mixing processes. These include port area, elevation above the bottom and orientation, effluent discharge flow rate, momentum flux, and buoyancy flux.

Far-field - the region of the receiving water where buoyant spreading motions and passive diffusion control the trajectory and dilution of the effluent discharge plume.

Far-field Processes - physical mixing mechanisms that are dominated by the ambient receiving water conditions, particularly ambient current velocity and density differences between the mixed flow and the ambient receiving water.

FAST-CORMIX - a version of CORMIX data entry with short questions and without help sections; can be chosen in main menu; for advanced users.

Flow Classification - the process of identifying the most appropriate generic qualitative description of the discharge flow undergoing analysis. This is accomplished by examining known relationships between flow patterns and certain calculated physical parameters.

Flux Characteristics - the properties of effluent discharge flow rate, momentum flux and buoyancy flux for the effluent discharge.

Forced Plume - see buoyant jet.

Generic Flow Class - a qualitative description of a discharge flow situation that is based on known relationships between flow patterns and certain physical parameters.

Height of Port (H0) - the average distance between the bottom and the average nozzle centerline.

High Water Slack (HWS) - the time of tidal reversal nearest to MHW

Horizontal Angle (SIGMA) - the angle measured counterclockwise from the ambient current directionix to the plane projection of the port center line.

Hydrodynamic Mixing Processes - the physical processes that determine the fate and distribution of effluent once it is discharged.

Input Data Sequence - a group of questions from one of four topical areas.

Intermediate-field Affects - induced flows in shallow waters which extend beyond the strictly near-field region of a multi-port diffuser.

Iteration Menu - the last menu (red panel) the user can choose after completion of a design case; allows iteration with different ambient/discharge/regulatory conditions.

Jet - see pure jet.

Laterally Bounded - refers to a water body which is constrained on both sides by banks such as rivers, streams, estuaries and other narrow water courses.

Laterally Unbounded - a water body which for practical purposes is constrained on at most one side. This would include discharges into wide lakes, wide estuaries and coastal areas.

Legal Mixing Zone (LMZ) - see regulatory mixing zone.

Length Scale - a dynamic measure of the relative influence of certain hydrodynamic processes on effluent mixing.

Length Scale Analysis - an approach which uses calculated measures of the relative influence of certain hydrodynamic processes to identify key aspects of a discharge flow so that a generic flow class can be identified.

Local Water Depth (HD) - see actual water depth.

Low Water Slack (LWS) - the time of tidal reversal nearest to MLW

Main Menu - the first menu (red panel) the user can choose from when entering CORMIX.

Manning's n - a measure of the roughness characteristics in a channel.

Maximum Tidal Velocity (Uamax) - the maximum velocity occurring within the tidal cycle

Mean Ambient Velocity (UA) - the average velocity of the receiving water body's flow.

Mean High Water (MLW) - the highest water level (averaged over many tidal cycles) in estuarine or coastal flows.

Mean Low Water (MLW) - the lowest water level (averaged over many tidal cycles) in estuarine or coastal flows.

Merging - the physical interaction of the discharge plumes from adjacent ports of a multi-port diffuser.

Mixing Zone - an administrative construct which defines a limited area or volume of the receiving water where the initial dilution of a discharge is allowed to occur. In practice, it may occur within the near-field or far-field of a hydrodynamic mixing process and therefore depends on source, ambient, and regulatoryx constraints.

Mixing Zone Regulations - The administrative construct that intends to prevent any harmful impact of a discharged effluent on the aquatic environment and its designated uses.

Momentum Jet - see pure jet.

Multi-port Diffuser - a structure with many closely spaced ports or nozzles that inject more than one buoyant jet into the ambient receiving water body.

Near-field - the region of a receiving water where the initial jet characteristic of momentum flux, buoyancy flux and outfall geometry influence the jet trajectory and mixing of an effluent discharge.

Near-Field Region (NFR) - a term used in the CORMIX printout for describing the zone of strong initial mixing where the so called near-field processes occur. It is the region of the receiving water where outfall design conditions are most likely to have an impact on in-stream concentrations.

Near-field Stability - the amount of local recirculation and re-entrainment of already mixed water back into the buoyant jet region. Stable discharge conditions are associated with weak momentum and deep water and are also sometimes called deep water conditions. Unstable discharge conditions have localized recirculation patterns and are also called shallow water conditions.

Negative Buoyancy - the measure of the tendency of an effluent discharge to sink in a receiving water.

Non-buoyant Jet - see pure jet.

Open Format - data input which does not require precise placement of numerical values in fixed fields and which allows character strings to be entered in either upper or lower case letters.

Passive Ambient Diffusion Processes - far-field mixing processes which arise due to existing turbulence in the ambient receiving water flow.

Plume - see buoyant jet.

Positive Buoyancy - the measure of the tendency of an effluent discharge to rise in the receiving water.

Post-Processor - several options available within CORMIX (main menu or iteration menu) for additi onal computation or data display, including a graphics package, a near-field buoyant jet model, and a far-field plume delineator.

Pure Jet - a discharge where only the initial momentum flux in the form of a high velocity injection causes turbulent mixing. It is also called momentum jet or non-buoyant jet.

Pure Plume - a discharge where only the initial buoyancy flux leads to local vertical accelerations which then lead to turbulent mixing.

Pycnocline - a horizontal layer in the receiving water where a rapid density change occurs.

Pycnocline Height (HINT) - the average distance between the bottom and a horizontal layer in the receiving water body where a rapid density change occurs.

Region Of Interest (ROI) - a user defined region of the receiving water body where mixing conditions are to be analyzed.xi Regulatory Mixing Zone (RMZ) - the region of the receiving water where mixing zone regulations are applied. It is sometimes referred to as the legal mixing zone.

Relative Orientation Angle (BETA) - the angle measured either clockwise or counterclockwise from the average plan projection of the port centerline to the nearest diffuser axis.

Schematization - the process of describing a receiving water body's actual geometry with a rect angular cross section.

Shallow Water Conditions - see near-field stability.

Stable Discharge - see near-field stability.

Staged Diffuser - a multi-port diffuser where all ports point in one direction, generally following the diffuser line.

Stagnant Conditions - the absence of ambient receiving water flow. A condition which rarely occurs in actual receiving water bodies.

Submerged Multi-port Diffuser - an effluent discharge structure with more t han one efflux opening that is located substantially below the receiving water surface.

Submerged Single Port Discharge - an effluent discharge structure with a single efflux opening that is located substantially below the receiving water surface.

Surface Buoyant Jets - positively or neutrally buoyant effluent discharges occurring horizontally at the water surface from a latterly entering channel or pipe.

Surface Width (BS) - the equivalent average surface width of the receiving water body determined from the equivalent rectangular cross sectional area during schematization.

Tidal cycle - the variation of ambient water depth and velocity as a function of time occurring due to tidal (lunar and solar) influences.

Tidal period (PERIOD) - the duration of the tidal cycle (on average 12.4 hours).

Tidal reversal - the two instances in the tidal cycle when the ambient velocity reverses its direction.

Toxic Dilution Zone (TDZ) - the region of the receiving water where the concentration of a toxic chemical may exceed the acute effects concentration.

Unidirectional Diffuser - a multi-port diffuser with all ports pointing to one side of the diffuser line and all ports oriented more or less normally to the diffuser line.

Unstable Discharge - see near-field stability.

Vertical Angle (THETA) - the angle between the port centerline and the horizontal plane.

Wake Attachment - a dynamic interaction of the effluent plume with the bottom that is forced by the receiving water crossflow.

Zone of Initial Dilution - a term sometimes used to describe the mixing zone for the discharge of municipal wastewater into the coastal ocean, limited to the extent of near-field mixing processes.xii 

## Metric Conversion Factors for Dimensions Used in CORMIX

Length: 1 m = 3.281 ft = 39.37 in = 0.0006214 mile

Velocity: 1 m/s = 3.281 ft/s (fps) = 2.237 miles/hr (mph) = 1.943 knots

Discharge: 1 m /s = 35.31 ft /s (cfs) 3 3 

### = 22.82 million-gal/day (mgd)

Density: 1000 kg/m = 62.43 lb/ft 3 3



### Temperature: C = ( F - 32.0) * 0.5556 o o1 

## I Introduction

The Cornell Mixing Zone Expert System Several factors provided the original (CORMIX) is a software system for the analysis, impetus for system development including: (a) the prediction, and design of aqueous toxic or considerable complexity of mixing processes in conventional pollutant discharges into diverse the aquatic environment, resulting from the great water bodies. It was developed under several diversity of discharge and site conditions and cooperative funding agreements between U.S. requiring advanced knowledge in a specialized EPA and Cornell University during the period field of hydrodynamics; (b) the failure of 1985-1995. It is a recomm ended analysis tool in previously existing models (e.g. the U.S. EPA key guidance documents (1,2,3) on the permitting plume m odels (4) originally developed for of industrial, municipal, thermal, and other point municipal discharges in deep coastal waters) to source discharges to receiving waters. Although adequately predict often routine discharge the system's major emphasis is on predicting the situations, especially for more shallow inland geometry and dilution characteristics of the initial sites; (c) the issuance in 1985 by the U.S. EPA of mixing zone so that compliance with water quality additional guidelines (1) for the permitting of toxic regulatory constraints may be j udged, the system aqueous discharges, placing yet another burden also predicts the behavior of the discharge plume on both applicants and regulators in delineating at larger distances. special zones for the initial mixing of these

The highly user-interactive CORMIX computer methods, so-called expert systems, for system is implemented on IBM-DOS compatible making accessible to the user, within a simple microcomputers, utilizes a rule-based systems personal computing environment, the expert's approach to data i nput and processing, and knowledge and experience in dealing with consists of three subsystems. These are: (a) complex engineering problems. CORMIX1 for the analysis of submerged single port discharges, (b) CORMIX2 for the analysis of Four separate publications (5,6,7,8) submerged multiport diffuser discharges and (c) describe the scientific basis for the CORMIX CORMIX3 for the analysis of buoyant surface system and demonstrate comparison and discharges. Without specialized training in validation with field and laboratory data. The hydrodynamics, users can make detailed results of these works are summarized in the predictions of mixing zone conditions, check peer-reviewed literature (9,10,11,12,13,14,15, compliance with regulations and readily 16,17). The CORMIX systems approach and its investigate the performance of alternative outfall performance relative to the earlier U.S. EPA designs. The basic CORMIX methodology relies plume models in the context of estuarine on the assumption of steady ambient conditions. applications is also described in EPA's technical However, recent versions also contain special guidance manual for performing waste load routines for the application to highly unsteady allocations in estuaries (3). environments, such as tidal reversal conditions, in which transient recirculation and pollutant build-up EPA's establis hed policy is to make the effects can occur. CORMIX system freely available to all potential

In addition, several post-processing facility at the U.S. EPA Center for Environmental options are available. These are CORJET (the Assessment Modeling (CEAM) in Athens, Cornell Buoyant Jet Integral Model) for the Georgia. Some of the CORMIX subsystems have detailed analysis of the near-field behavior of been available to the i ndustrial and regulatory buoyant jets, FFLOCATR (the Far-Field Plume user communities since December 1989 when Locator) for the far-field delineation of discharge distribution of CORMIX1 was commenced by plumes in non-uniform river or estuary Cornell University for the purpose of identifying environments, and CMXGRAPH, a graphics subtle programming errors through application to package for plume plotting. actual mixing zone analysis problems by a substances; and (d) the availability of new

users through its modeling software distribution2 controlled users group. After this testing was management positions desiring an overview of deemed complete, CEAM commenced the the CORMIX systems capabilities, and 2) distribution of CORMIX1 in November 1990. A technical staff needing assistance in actual similar approach was used to introduce CORMIX2 applications. C hapter II provides a summary of which began CEAM distribution in Oct ober 1991. the physical processes of effluent mixing, as well In 1992, CORMIX1, CORMIX2, and CORMIX3 as an overview of the regulatory background and were integrated a single program and distributed practice on mixing zone applications. The by USEPA-CEAM as CORMIX Version 2.1 as of general features of the CORMIX system are 1993. explained in Chapter III including summaries of:

Additional development of the post- overall system structure and method of processor modules, including plume graphics, the processing information, (c) user interaction, and jet-integral model, and the far-field locator, were (d) individual computational elements. Detailed added to the system and distributed as CORMIX guidance on the preparation and entry of input Version 3.0 as of 1994. data, as r equired by the three CORMIX

This manual describes the operation of a provides a description of system output, revised version, including a special routine for containing descriptive, quantitative, and gr aphical unsteady tidal applications, denoted as CORMIX information on the predicted effluent flow. Version 3.1 that has been distributed by Cornell Chapter VI describes the background, input and as of June 1995. A slightly updated Version 3.2 output features of the CORJET jet integral model will be distributed by USEPA-CEAM as of and the far-field plume locator program September 1996. FFLOCATR. The closing remarks in C hapter VII

The objectives of this user's guide are as user support, and on possible future follows: (a) to provide a comprehensive developments and enhancements. description of the CORMIX system; (b) to provide guidance for assembly and preparation of Appendices to this guide present four required input data for all three subsystems as case studies on the application of all three well as the post-processor models; (c) to CORMIX subsystems and its post-processor delineate ranges of applicability of the m odels. These are adapted from actual subsystems; (d) to provide guidance for the situations and illustrate the complete input interpretation and graphical display of system r equirements and output capabilities of the output; and (e) to illustrate practical system system. In addition, some of the assumptions on application through several case studies. data schematization, problem simplification, and

This manual is organized to meet the displays are discussed in a context typical of informational needs of two distinctly different many mixing zone model applications. groups of readers: 1) pers onnel in environmental (a) predictive capabilities and limitations, (b)

subsystems, is given in Chapter IV. Chapter V

contain information on system availability and

output interpretation, and construction graphical

### 3 

## II Background: Mixing Processes and Mixing Zone Regulations

When performin g desi g n work and and construction details represent additional predictive studies on effluent dischar g e problems, g eometric features; and for surface dischar g es it is important to clearly distin g uish between the the cross-section and orientation of the flow physical aspects of hydrodynamic mixing processes that determine the effluent fate and distribution, and the administrative construct of mixing zone regulations that intend to prevent any harmful impact of the effluent on the aquatic environment and associated uses.

2.1 Hydrodynamic Mixing Processes

The mixin g behavior of any wastewater dischar g e is g overned by the interplay of ambient conditions in the receivin g water body and by the dischar g e characteristics.

The ambient conditions in the receivin g water body, be it stream, river, lake, reservoir, estuary or coastal waters, are described by the water body's g eometric and dynamic characteristics. Important g eometric parameters include plan shape, vertical cross-sections, and bathymetry, especially in the dischar g e vicinity. Dynamic characteristics are g iven by the velocity and density distribution in the water body, a g ain primarily in the dischar g e vicinity. In many cases, these conditions can be taken as steady-state with little variation because the time scale for the mixin g processes is usually of the order of minutes up to perhaps one hour. In some cases, notably tidally influenced flows, the ambient conditions can be hi g hly transient and the assumption of steady-state conditions may be inappropriate. In this case, the effective dilution of the dischar g e plume may be reduced relative to that under steady state conditions.

The discharge conditions relate to the g eometric and flux characteristics of the submer g ed outfall installation. For a sin g le port dischar g e the port diameter, its elevation above the bottom and its orientation provide the g eometry; for multiport diffuser installations the

arran g ement of the individual ports alon g the diffuser line, the orientation of the diffuser line, enterin g the ambient watercourse are important. The flux characteristics are g iven by the effluent dischar g e flow rate, by its momentum flux and by its buoyancy flux. The buoyancy flux represents the effect of the relative density difference between the effluent dischar g e and ambient conditions in combination with the g ravitational acceleration. It is a measure of the tendency for the effluent flow to rise (i.e. positive buoyancy ) or to fall (i.e. negative buoyancy ).

The hydrodynamics of an effluent continuously dischar g in g into a receivin g water body can be conceptualized as a mixin g process occurrin g in two separate re g ions. In the first

re g ion, the initial jet characteristics of momentum flux, buoyancy flux, and outfall g eometry influence the jet trajectory and mixin g . This re g ion will be referred to as the " near-field ", and encompasses the buoyant jet flow and any surface, bottom or terminal layer interaction. In this near-field re g ion, outfall desi g ners can usually affect the initial mixin g characteristics throu g h appropriate manipulation of desi g n variables.

As the turbulent plume travels further away from the source, the source characteristics become less important. Conditions existin g in the ambient environment will control trajectory and dilution of the turbulent plume throu g h buoyant spreadin g motions and passive diffusion due to ambient turbulence. This re g ion will be referred to here as the " far-field ". It is stressed at this point that the distinction between near-field and far-field is made purely on hydrodynamic g rounds. It is unrelated to any re g ulatory mixin g zone definitions.

2.1.1 Near-Field Processes

Three important types of near-field processes are submer g ed buoyant jet mixin g , boundary interactions and surface buoyant jet mixin g as described in the followin g para g raphs.

### 4 Submerged Buoyant Jet Mixing: The effluent ports. After merging , a two-dimensional buoyant flow from a submer g ed dischar g e port provides a jet plane is formed as illustrated in Fi g ure 2.1d. velocity discontinuity between the dischar g ed fluid Such plane buoyant jets resultin g from a multiport and the ambient fluid causin g an intense shearin g diffuser dischar g e in deep water can be further action. The shearin g flow breaks rapidly down affected by ambient currents and by density into a turbulent motion. The width of the zone of stratification as discussed in the precedin g hi g h turbulence intensity increases in the direction para g raph. of the flow by incorporatin g ("entrainin g ") more of the outside, less turbulent fluid into this zone. In this manner, any internal concentrations (e. g . fluid momentum or pollutants) of the dischar g e flow become diluted by the entrainment of ambient water. Inversely, one can speak of the fact that both fluid momentum and pollutants become g radually diffused into the ambient field.

The initial velocity discontinuity may arise in different fashions. In a " pure jet " (also called "momentum jet" or "non-buoyant jet"), the initial momentum flux in the form of a hi g h-velocity injection causes the turbulent mixin g . In a " pure plume ," the initial buoyancy flux leads to local processes provide a transition between the vertical accelerations which then lead to turbulent buoyant jet mixin g process in the near-field, and mixin g . In the g eneral case of a " buoyant jet " (also called a "forced plume"), a combination of initial momentum flux and buoyancy flux is responsible for turbulent mixin g

. Thus, buoyant jets are characterized by a narrow turbulent fluid zone in which vi g orous The assessment of near-field stability

, mixin g takes place. Furthermore, dependin g on i.e. the distinction of stable or unstable conditions, dischar g e orientation and direction of buoyant is a key aspect of effluent dilution analyses. It is acceleration, curved trajectories are g enerally especially important for understandin g the established in a sta g nant uniform-density behavior of the two-dimensi onal plumes resultin g environment as illustrated in Fi g ure 2.1a. from multiport diffusers, as shown by some

Buoyant jet mixin g is further affected by ambient currents and density stratification. The role of ambient currents is to g radually deflect the buoyant jet into the current direction as illustrated in Fi g ure 2.1b and thereby induce additional mixin g . The role of ambient density stratification is to counteract the vertical acceleration within the buoyant jet leadin g ultimately to trappin g of the flow at a certain level. Fi g ure 2.1c shows a typical buoyant jet shape at the trappin g or terminal level.

Finally, in case of multiport diffusers, the individual round buoyant jets behave independently until they interact, or mer g e, with each other at a certain distance from the efflux Boundary Interaction Processes and NearField Stability: Ambient water bodies always have vertical boundaries. These include the water surface and the bottom, but in addition, "internal boundaries" may exist at pycnoclines. Pycnoclines are layers of rapid density chan g e. Dependin g on the dynamic and g eometric characteristics of the dischar g e flow, a variety of interaction phenomena can occur at such boundaries, particularly where flow trappin g may
occur.
In essence, boundary interaction

between buoyant spreadin g and passive diffusion in the far-field. They can be g radual and mild, or abrupt leadin g to vi g orous transition and mixin g processes. They also can si g nificantly influence the stability of the effluent dischar g e conditions.

examples in Fi g ure 2.2. " Stable discharge " conditions, usually occurrin g for a combination of stron g buoyancy, weak momentum and deep water, are often referred to as " deep water " conditions (Fi g ures 2.2a,c). " Unstable discharge " conditions, on the other hand, may be considered synonymous to " shallow water " conditions (Fi g ure 2.2b,d). Technical discussions on dischar g e stability are presented elsewhere (18,19).

A few important examples of boundary interaction for a sin g le round buoyant jet are illustrated in Fi g ure 2.3. If a buoyant jet is bentover by a cross-flow, it will g radually approach the surface, bottom or terminal level and will under g o a smooth transition with little additional mixin gimpingement point can take on one of the

following forms: (a) If the flow has sufficient buoyancy it will ultimately form a stable layer at the surface (Figure 2.3b). In the presence of weak ambient flow this will lead to an upstream intrusion against the ambient current. (b) If the buoyancy of the effluent flow is weak or its momentum very high, unstable recirculation phenomena can occur in the discharge vicinity (Figure 2.3~). This local recirculation leads to reentrainment of already mixed water back into the buoyant jet region. (c) In the intermediate case, a combination of localized vertical mixing and upstream spreading may result (Figure 2.3d).

holly lurne-like

O) Buoyant Jet in Stagnant Uniform Ambient

Ambient

Slronqly deflected

Neokly deflected

b) Euoyont Jet in Uniform Ambient Cross-Current Another type of interaction process concerns submerged buoyant jets discharging in the vicinity of the water bottom into a stagnant or flowing ambient. Two types of dynamic interaction processes can occur that lead to rapid attachment of the effluent plume to the water bottom as illustrated in Figure 2.4. These are wake attachment forced by the receiving water’s crossflow or Coanda attachment forced by the entrainment demand of the effluent jet itself. The latter is due to low pressure effects as the jet pertphely is close to the water bottom.

Terminal

C) Buoyant Jet in Stagnant Stratified Ambient

Round_, Plane p jets I jet

d) Side View Tap View
Jet Merging for Unidirectional Multipart Diffuser Forming Plane Buoyant Jet

Figure 2.1: Typical buoyant jet mixing flow patterns under different ambient conditions



### 5

-

### 6 Figure 2.2: Examples of near-field stability and instability conditions for submerged discharges in limited water depth

### 7 Figure 2.3: Examples of boundary interactions for submerged jets in finite depth

### 8 Figure 2.4: Examples of wake (crossflow induced) attachment and Coanda attachment conditions for jets discharging near boundaries

### 9 Surface Buoyant Jet Mixing: Positively buoyant jets discharged horizontally along the water surface from a laterally entering channel or pipe (Figure 2.5) bear some similarities to the more classical submerged buoyant jet. For a relatively short initial distance, the effluent behaves like a momentum jet spreading both laterally and vertically due to turbulent mixing. After this stage, vertical entrainment becomes inhibited due to buoyant damping of the turbulent motions, and the jet experiences strong lateral spreading. During stagnant ambient conditions, ultimately a reasonably thin layer may be formed at the surface of the receiving water; that layer can undergo the transient buoyant spreading motions depicted in Figure2.5a.

2.5: Typical buoyant surface jet mixing flow patterns under stagnant or flowing ambient conditions

### 10 In the presence of ambient crossflow, Far-field mixin g processes are buoyant surface jets may exhibit any one of characterized by the lon g itudinal advection of the followin g three types of flow features: They may mixed effluent by the ambient current velocity. form a weakly deflected jet that does not interact with the shoreline (Fi g ure 2.5b). When the crossflow is stron g , they may attach to the downstream boundary formin g a shore-hu gg in g plume (Fi g ure 2.5c). When a hi g h dischar g e buoyancy flux combines with a weak crossflow, the buoyant spreadin g effects can be so stron g that an upstream intrudin g plume is formed that also stays close to the shoreline (Fi g ure 2.5d).

Intermediate-Field Effects for Multiport lar g e distances in the transverse direction, Diffuser Discharges: Some multiport diffuser installations induce flows in shallow water which extend beyond the strict near-field re g ion. The resultin g plumes are sometimes referred to as the "intermediate-field" (18) because they interact with the receivin g water at distances that are substantially g reater than the water depth; the order of ma g nitude of the water depth is typically used to define the dimensions of the near-field

re g ion. Intermediate fields may occur when a multiport diffuser represents a lar g e source of momentum with a relatively weak buoyancy effect. Such a diffuser will have an unstable near-field with shallow water conditions. For certain diffuser g eometries (e. g . unidirectional & sta g ed diffuser types; see Section V) stron g motions can be induced in the shallow water environment in the form of vertically mixed currents that laterally entrain ambient water and may extend over lon g distances before they re-stratify or dissipate their momentum.
Another type of interaction process concerns submer g ed buoyant jets dischar g in g in the vicinity of the water bottom into a sta g nant or flowin g ambient. Two types of dynamic interaction processes can occur that lead to rapid attachment of the effluent plume to the water bottom as illustrated in Fi g ure 2.4. These are wake attachment forced by the receivin g water's crossflow or Coanda attachment forced by the entrainment demand of the effluent jet itself. The latter is due to low pressure effects as the jet periphery is close to the water bottom.

2.1.2 Far-Field Processes Buoyant Spreading Processes: These are defined as the horizontally transverse spreadin g of the mixed effluent flow while it is bein g advected downstream by the ambient current. Such spreadin g processes arise due to the buoyant forces caused by the density difference of the mixed flow relative to the ambient density. They can be effective transport mechanisms that can quickly spread a mixed effluent laterally over

particularly in cases of stron g ambient stratification. In this situation, effluent of considerable vertical thickness at the terminal level can collapse into a thin but very wide layer unless this is prevented by lateral boundaries. If the dischar g e is non-buoyant, or weakly buoyant, and the ambient is unstratified, there is no buoyant spr eadin g re g ion in the far-field, only a passive diffusion re g ion.

Dependin g on the type of near-field flow and ambient stratification, several types of buoyant spreadin g may occur. These include: (a) spreadin g at the water surface, (b) spreadin g at the bottom, (c) spreadin g at a sharp internal interface (pycnocline) with a density jump, or (d) spreadin g at the terminal level in continuously stratified ambient fluid. As an example, the definition dia g ram and structure of surface buoyant spreadin g processes somewhat downstream of the dischar g e in unstratified crossflow is shown in Fi g ure 2.6.

The laterally spreadin g flow behaves like a density current and entrains some ambient fluid in the "head re g ion" of the current. Durin g this phase, the mixin g rate is usually relatively small, the layer thickness may decrease, and a subsequent interaction with a shoreline or bank can impact the spreadin g and mixin g processes.

Passive Ambient Diffusion Processes: The existin g turbulence in the ambient environment becomes the dominatin g mixin g mechanism at sufficiently lar g e distances from the dischar g e point. In g eneral, the passively diffusin g flow g rows in width and in thickness until it interacts

### 11 The strength of the ambient diffusion mechanism depends on a number of factors relating mainly to the geometry of the ambient shear flow and the amount of ambient stratification. In the context of classical diffusion theory (20), gradient diffusion processes in the bounded flows of rivers or narrow estuaries can be described by constant diffusivities in the vertical and horizontal direction that depend on turbulent intensity and on channel depth or width as the length scales. In contrast, wide "unbounded" channels or open coastal areas are characterized by plume size dependent diffusivities leading to accelerating plume growth described, for example, by the "4/3 law" of diffusion. In the presence of a stable ambient stratification, the vertical diffusive mixing is generally strongly damped.

Figure 2.6: Buoyant spreading processes downstream of the near-field region (example of spreading along the water surface)

### 12 Figure 2.7: Passive ambient diffusion process with advection in the far-field

2.2 Mixing Zone Regulations The discharge of waste water into a water body can be considered from two vantage points regarding its impact on ambient water quality. On a larger scale, seen over the entire receiving water body, care must be taken that water quality conditions that protect designated beneficial uses are achieved. This is the realm of the general waste load allocation (WLA) procedures and models.

On a local scale, or in the immediate discharge vicinity, additional precautions must be taken to insure that high initial pollutant concentrations are minimized and constrained to small zones, areas, or volumes. The generic definition of these zones, commonly referred to as " mixing zones ", is embodied in federal water quality regulations and often cited in the regulations of permit granting authorities. As stated previously, mixing zones are administrative constructs that are independent of hydrodynamic mixing processes.

2.2.1 Legal Background

The Clean Water Act of 1977 defines five general categories of pollutants. These are: (a) conventional, (b) nonconventional, (c) toxics, (d) heat, and (e) dredge and fill spoil. The Act distinguishes between new and existing sources

### 13 for settin g effluent standards. Pollutants to adopt a mixin g zone and to specify its desi g nated as "conventional" would be " g enerally dimensions. The U.S. EPA allows the use of a those pollutants that are naturally occurrin g , mixin g zone in permit applications except where biode g radable, oxy g en demandin g materials and one is prohibited in State re g ulations. A previous solids. In addition, compounds which are not review (5) of indivi dual State mixin g zone policies toxic and which are similar in characteristics to (1,22) f ound that 48 out of 50 States make use of naturally occurrin g , biode g radable substances are a mixin g zone in some form; the exceptions are to be desi g nated as conventional pollutants for Arizona and Pennsylvania. State re g ulations the purposes of the provision." Examples of dealin g with streams or rivers g enerally limit conventional pollutants are: biochemical oxy g en mixin g zone widths or cross-secti onal areas, and demand (BOD), total suspended solids, and fecal allow len g ths to be determined on a case by case coliform bacteria. Pollutants desi g nated as basis. "nonconventional" would be "those which are not toxic or conventional", and some examples are: In the case of lakes, estuaries and coastal chemical oxy g en demand (COD), fluoride, and waters, some states specify the surface area that ammonia. "Toxic" pollutants are those that cause can be affected by the dischar g e. The surface harmful effects, either acute or chronic, at very area limitation usually applies to the underlyin g low concentrations; examples of some desi g nated water column and benthic area. In the absence of toxic substances are: nickel, chloroform, or specific mixin g zone dimensions, the actual shape benzidine. and size is determined on a case-by-case basis.

2.2.2 Mixin g Zone Definitions Special mixin g zone definitions have been

The mixin g zone is defined as an wastewater into the coastal ocean, as re g ulated

" allocated impact zone " where numeric water quality criteria can be exceeded as lon g as acutely toxic conditions are prevented. A mixin g zone can be thou g ht of as a limited area or volume where the initial dilution of a dischar g e occurs (21). Water quality standards apply at the z one was labeled as the " zone of initial dilution " boundary of the mixin g zone, not within the mixin g in which rapid mixin g of the waste stream (usually zone itself. The U.S. EPA and its predecessor the risin g buoyant fresh water plume within the

a g encies have published numerous documents ambient saline water) takes place. EPA requires g ivin g g uidance for determinin g mixin g zones. that the "zone of initial dilution" be a re g ularly Guidance published by U.S. EPA in the 1984 shaped area (e. g . circular or rectan g ular) Water Quality Standards Handbook (21) surroundin g the dischar g e structure (e. g

. supersedes these sources. submer g ed pipe or diffuser line) that

In settin g requirements for mixin g zones, st andards) pollutant concentrations under desi g n U.S. EPA (22) requires that "the area or volume of conditions (23). In practice, limitin g boundaries an individual zone or g roup of z ones be limited to defined by dimensions equal to the water depth an area or volume as small as practicable that will measured horizontally from any point of the not interfere with the desi g nated uses or with the dischar g e structure are accepted by the EPA established community of aquatic life in the provided they do not violate other mixin g zone
se g ment for which the uses are desi g nated," and restrictions (23). the shape be "a simple confi g uration that is easy to locate in the body of water and avoids 2.2.3 Special Mixin g Zone Requirements for impin g ement on biolo g ically important areas," and Toxic Substances "shore hu gg in g plumes should be avoided."

The U.S. EPA rules for mixin g zones criteria for the allowable concentration of toxic

reco g nize the State has discretion whether or not substances: a criterion maximum concentration developed for the dischar g e of municipal

under Section 301(h) of the Clean Water Act (23). Frequently, these same definitions are used also for industrial and other dischar g es into coastal waters or lar g e lakes, resultin g in a plurality of terminolo g y. For those dischar g es, the mixin g

encompasses the re g ions of hi g h (exceedin g

The U.S. EPA maintains two water quality

### 14 (CMC) to protect a g ainst acute or lethal effects; situations of severe bottom interaction and a criterion continuous concentration (CCC) to and surface interaction. protect a g ainst chronic effects (1). The CMC value is g reater than or equal to the CCC value --- The CMC must be met within a distance and is usually more restrictive. The CCC must be of 5 times the local water depth in any met at the ed g e of the same re g ulatory mixin g horizontal direction. The local water depth zone specified for conventional and noncon- is defined as the natural water depth ventional dischar g es. (existin g prior to the installation of the

Lethality to passin g or g anisms within the zone desi g n condition (e. g . low flow for mixin g zone can be prevented in one of four rivers). This restriction will prevent ways: locatin g the dischar g e in very shallow

The first alternative is to meet the CMC which would result in si g nificant surface criterion within the pipe itself. and bottom concentrations (1).

The second alternative is to meet the A fourth alternative is to show that a CMC within a short distance from the outfall. If driftin g or g anism would not be exposed more than dilution of the toxic dischar g e in the ambient 1-hour to avera g e concentrations exceedin g the environment is allowed, a toxic dilution zone (TDZ) , which is usually more restrictive than the le g al mixin g zone for conventional and nonconventional pollutants, may be used. The revised 1991 Toxics TSD document (1) recommends for new dischar g es a minimum exit velocity of 3 meters per second (10 feet per second) in order to provide sufficiently rapid mixin g that would minimize or g anism exposure time to toxic material. The TSD does not set a requirement in this re g ard, reco g nizin g that the restrictions listed in the followin g para g raph can in many instances also be met by other desi g ns, especially if the ambient velocity is lar g e.

As the third alternative, the outfall desi g n must meet the most restrictive of the followin g g eometric restrictions for a TDZ:

--- The CMC must be met within 10% of the distance from the ed g e of the outfall structure to the ed g e of the re g ulatory mixin g zone in any spatial direction.

--- The CMC must be met within a distance of 50 times the dischar g e len g th scale in any spatial direction. The dischar g e len g th scale is defined as the square-root of the cross-sectional area of any dischar g e outlet. This restriction is intended to ensure a dilution factor of at least 10 within this distance under all possible circumstances, includin g dischar g e outlet) prevailin g under mixin g

environments or very close to shore,

CMC.

2.2.4 Current Permittin g Practice on Mixin g Zones

It is difficult to g eneralize the actual practice in implementin g the mixin g zone
re g ulations, g iven the lar g e number and diverse types of jurisdictions and permit- g rantin g authorities involved. By and lar g e, however, current procedure falls into one of the followin g approaches, or may involve a combination thereof.

(i) The mixin g zone is defined by some numerical dimension, as discussed above. The applicant must then demonstrate that the existin g or proposed dischar g e meets all applicable standards for conventional pollutants or for the CCC of toxic pollutants at the ed g e of the specified mixin g zone.
(ii) No numerical definition for a mixin g zone may apply. In this case a mixin g zone dimension may be proposed by the applicant. To do so the applicant g enerally uses actual concentration measurements for existin g dischar g es, dye dispersion tests or model predictions to show at what plume distance, width,

or re g ion, the applicable standard will be met. The applicant may then use further ecolo g ical or water use-oriented ar g uments to demonstrate that

### 15 the size of that predicted re g ion provides reasonable protection. The permittin g authority 2.2.5 Relationship Between Actual Hydrodynamic may evaluate that proposal, or sometimes pursue Processes and Mixin g Zone Dimensions its own independent proposal for a mixin g zone.

This approach resembles a ne g otiatin g process actual hydrodynamic processes of mixin g . With with the objective of providin g optimal protection few exceptions, the toxic dilution criteria apply to of the aquatic environment consistent with other the near-field of most dischar g es since the TDZ uses. criteria (2) are spatially hi g hly restrictive. The

As re g ards the acute, or CMC, criterion for located in the near-field or the far-field of the toxic pollutants, the spatial restrictions embodied actual effluent dischar g e flow since they are in the Toxics TSD document (1) call for very administratively determined by the permit- g rantin g specific demonstrations of how the CMC criterion authority. Thus, the analyst must have tools at his is met at the ed g e of the "toxic dilution zone". disposal with the capability to address both the A g ain, field tests for existin g dischar g es or predictive models may be used. The spatial requirements in mixin g zone
re g ulations are not always correlated with the

re g ular mixin g zone boundaries, however, may be

near and far-field situations.

### 1617 

## III General Features of the CORMIX System

This section provides a general are prone to locally recirculating flows. Other description of common features of CORMIX. non- applicable cases may arise to complicated CORMIX Version 3.1 has three different discharge geometries in which case CORMIX subsystem modules for diverse discharge advises the user not to proc eed with the analysis. conditions. The subsystems are CORMIX1, Whenever the model is applicable extensive CORMIX2, and CORMIX3 for the analysis of comparison with available field and laboratory submerged single port, submerged multipo rt, and data has shown that the CORMIX predictions on buoyant surface outfall configurations, dilutions and concentrations, with associated respectively. Furthermore, two post-processor plume geometries, are accurate to within ± 50 % models CORJET, a near-field jet integral model, (standard deviation). and FFLOCATR, a far-field plume locator in nonuniform channels, are included. The following two The met hodology provides answers to sections give a detailed guidance for developing questions that typically arise during the the required input data and for understanding application of mixing z one regulations for both program output. Reference is made throughout conventional and toxic discharges. More this document to CORMIX Version 3.1 dated June importantly, this is accomplished by utilizing the 1995 or Version 3.2 dated September 1996; other customary approaches often used in evaluating versions may differ somewhat. and implementing mixing zones, thereby providing

3.1 Overview

The CORMIX system represents a robust and versatile computerized methodology for predicting both the qualitative features (e.g. flow classification) and the quantitative aspects (e.g. dilution ratio, plume trajectory) of the hydrodynamic mixing processes resulting from different discharge configurations and in all types of ambient water bodies, including small streams, large rivers, lakes, reservoirs, estuaries, and coastal waters. The methodology: (a) has been extensively verified by the developers through comparison of simulation results to available field and laboratory data on mixing processes (5,6,7,8), (b) has undergone independent peer review in journal proceedings (9,10,11,12,13, 14,15,16,17) and (c) is equally applicable to a wide range of problems from a simple single submerged pipe discharge into a small stream with rapid cross-sectional mixing to a complicated multiport diffuser installation in a deeply stratified coastal water.

System experience suggests that CORMIX1 applies to better than 95% of submerged single-port designs, CORMIX2 to better than 80% of multiport diffusers, and CORMIX3 to better than 90% of surface discharges. Lack of applicability is usually given by highly non-uniform ambient flow conditions that a common framework for both applicants and regulatory personnel to arrive at a consensus view of the available dilution and plume trajectory for the site and effluent discharge characteristics.

The methodology also provides a way for personnel with little or no training in hydrodynamics to investigate improved design solutions for aquatic discharge structures. To limit misuse, the system contains limits of applicability that prevent the simulation ofsituations for which no safe predictive methodology exists, or for discharge geometries that are undesirable from a hydrodynamic viewpoint. Furthermore, warning labels, data screening mechanisms, and alternative design recommendations are furnished by the system. The system is not fool proof, however, and final results should always be examined for reasonableness.

Finally, CORMIX is an educational tool that intends to make the user more knowledgeable and appreciative about effluent discharge and mixing processes. The system is not simply a black box that produces a final numerical or graphical output, but contains an interactive menu of user guidance, help options, and explanatory material of the relevant physical processes. These assist users in understanding model predictions and exploring the sensitivity of model predictions to assumptions.18 3.2 Capabilities and Major Assumptions of the Three Subsystems and the Post-Processor Models

3.2.1 CORMIX Subsystems

CORMIX1 predicts the geometry and dilution characteristics of the effluent flow resulting from a submerged single port diffuser discharge , of arbitrary density (positively, neutrally, or negatively buoyant) and arbitrary location and geometry, into an ambient receiving water body that may be stagnant or flowing and have ambient density stratification of different types.
CORMIX2 applies to three commonly used types of submerged multiport diffuser discharges under the same g eneral effluent and ambient conditions as CORMIX1. It analyzes unidirectional, staged, and alternating designs of multiport diffusers and allows for arbitrary alignment of the diffuser structure within the ambient water body, and for arbitrary arrangement and orientation of the individual ports. For complex hydrodynamic cases, CORMIX2 uses the "equivalent slot diffuser" concept and thus neglects the details of the individual jets issuing from each diffuser port and their merging process, but rather assumes that the flow arises from a long slot discharge with equivalent dynamic characteristics. Hence, if details of the effluent flow behavior in the immediate diffuser vicinity are needed, an additional CORMIX1 simulation for an equivalent partial effluent flow may be recommended.

CORMIX3 analyzes buoyant surface discharges that result when an effluent enters a larger water body laterally, through a canal, channel, or near-surface pipe. In contrast to CORMIX1 and 2, it is limited to positively or neutrally buoyant effluents. Different discharge geometries and orientations can be analyzed including flush or protruding channel mouths, and orientations normal, oblique, or parallel to the bank.

Additional major assumptions incl ude the following:

--- All subsystems require that the actual cross-section of the water body be described as a rectangular straight uniform channel that may be bounded laterally or unbounded. The ambient velocity is assumed to be uniform within that cross-section. --- In addition to a uniform ambient density possibility, CORMIX allows for three generic types of ambient stratification profiles to be used for the approximation of the actual vertical density distribution (see Section 4.3). --- All CORMIX subsystems are in principle steady-state models , however recent developments (beginning with Version 3.1) allow the analysis of unsteady mixing in tidal environments

. --- All CORMIX systems can predict mixing for both conservative and first-order decay processes, and can simulate heat transfer from thermal plumes.

3.2.2 Post-Processor Models CORJET and FFLOCATR

CORJET, the Cornell Buoyant Jet Integral Model, is a buoyant jet integral model that predicts the jet trajectory and dilution characteristics of a single round jet or of a series of merging jets from a multiport diffuser with arbitrary discharge direction and positive, neutral or negative buoyancy in a general ambient environment. The ambient conditions can be highly non-uniform with both ambient current magnitude, current direction, and density a function of vertical distance. In general, CORJET can be used as an enhancement to the near-field predictions provided by CORMIX1 or 2 in order to investigate local details that have been simplified within the CORMIX representation. The major limitation of CORJET lies in the assumption of an infinite receiving water body , similar to all other available jet integral type models. Thus, CORJET should only be used after an initial CORMIX classification has shown that the single or multiple port discharge is indeed of the deep water type, i.e. hydrodynamically stable, without boundary interactions.

FFLOCATR, the Far-Field Plume Locator, uses the cumulative discharge method to delineate the CORMIX predicted far-field plume19 within the actual irregular (meandering or winding) possible generic flow configurations. HYDRO river or estuary channel geometry with uneven performs the actual detailed numerical prediction distribution of the ambient flow. of the effluent plume characteristics. Finally, SUM

3.3 System Processing Sequence and Structure

The general CORMIX layout appears in Figure 3.1, which shows the overall structure and the execution sequence of the program elements. The system has overall common data input features for the three different discharge elements. During program execution, the elements are loaded automatically and sequentially by the system. Each element provides user interaction and prompting in response to displayed information. This may somewhat extend the total time required for a single CORMIX session, but has offsetting benefit of allowing the user to gain process knowledge and insight on design sensitivity.

The user has numerous options with the Main Menu at start-up. Option 1 is to start a new CORMIX session. Option 2 is to re-run andmodify a former case. Option 3 is to simply redisplay (without new computation) results of aformer design case. Option 4 is to use the PostProcessor , which includes the CORJET near-field jet integral model, the FFLOCATR far-field locator, and the plume display graphics which will be discussed in Section V of this document. Option 5 is the file manager which lists all files from previous simulations. Option 6 is to set/change CORMIX system speed. Here the user can select REGULAR CORMIX, completewith detailed queries and user help, or FASTCORMIX, which has terse questions and limited user help. Option 7 contains system information and reference material. Option 7 is to quit the CORMIX system and return to DOS.

The common program elements of CORMIX are composed of DATIN, PARAM, CLASS, HYDRO, and SUM (Figure 3.1). DATIN is the program element for the entry of data and initialization of other program elements. PARAM uses the input data to compute a number of important physical parameters and length scales, as precursor to CLASS which performs the hydrodynamic classification of the given discharge/ambient situation into one of many summarizes the results from the classification and prediction, interprets them as regards mixing zone regulations, suggests design alternatives, and allows sensitivity analysis to be conveniently conducted using the current i nput data. At this point the iteration menu allows the user to perform an iteration with different ambient/discharge/regulatory conditions, or starta new design case, or make use of the postprocessor options.

Due to its diverse programming requirements, CORMIX is written in two programming languages: VP-Expert, an "expert systems shell", and Fortran. The former is powerful in knowledge representation and logical reasoning, while the latter is adept at mathematical computations. Program elements DATIN, PARAM, CLASS, and SUM are written exclusively in VP-Expert. HYDRO is written in VP-Expert, but uses three Fortran executables HYDRO1, 2 and 3 for the actual detailed computation of plume characteristics. Finally, C++ is used in the specially developed graphics package CMXGRAPH.

3.4 CORMIX Data Input Features

All data is entered interactively in response to the CORMIX system prompts generated by the data input program element DATIN. DATIN queries the user for a complete specification of the physical environment of the discharge, as well as the applicable regulatory considerations for the situation undergoing analysis. A CORMIX session commences with questions on four topics which are asked sequentially in this order: site/case descriptions, ambient conditions, discharge characteristics, and regulatory mixing zone definitions. Data entry is entirely guided by the system and the available advice menu options provide expanded descriptions of the questions, if clarification is needed.

Chapter IV provides complete details on input specification for the three CORMIX discharge subsystems. Chapter VI deals with the input features of the post-processor models CORJET and FFLOCATR.21 3.5 Logic Elements of CORMIX: Flow Classification

To make predictions of an effluent discharge's dilution and plume trajectory, CORMIX typically combines the solutions of several simple flow patterns to provide a complete analysis from the efflux location all the way into the far-field.

The logic processing elements of CORMIX identify which solutions should be combined to provide the complete analysis. This process, called flow classification , develops a generic qualitative description of the discharge flow and is based on known relationships between flow patterns and certain calculated physical parameters.

PARAM is the program element that computes relevant physical parameters including: the various length scales, fluxes, and other valuesneeded for the execution of other program elements. Length scales are calculated measures of the length of dynamic influence of various physical processes (see Chapters IV and V).

At the heart of CORMIX is a flow classification system contained in the program element CLASS. It provides a rigorous and robust expert knowledge base that carefully distinguishes among the many hydrodynamic flow patterns that a discharge may exhibit. As examples, these possibilities include discharge plumes attaching to the bottom, plumes vertically mixing due to instabilities in shallow water, plumes becoming trapped internally due to density stratification, and plumes intruding upstream against the ambient current due to buoyancy, and many others. Theoretically based hydrodynamic criteria using length scale analysis and empirical knowledge from laboratory and field experimentation, are applied in a systematic fashion to identify the most appropriate flow classification for a particular analysis situation. For all three subsystems, a total of about 80 generic flow configurations or classes can be distinguished.

The classification procedure of CORMIX is based on technical principles and has been verified by the developers through repeated testing and data comparison. It has also undergone independent peer review and the four documentation manuals (5,6,7,8) give the detailed scientific background for the classification scheme, in form of a number of criteria. The actual criteria constants are listed in the technical reports with comments on their sources and degree of reliability. Experienced users, especially those involved in research applications, may want to inspect these data values contained in the source code and occasionally vary some constant values within certain limits in order to examine improved prediction fits with available high-quality data. Extreme caution must be exercised when doing that as some values are interdependent; furthermore, if changes are made, they should be carefully documented.

When CLASS has executed, a description of the particular flow class is available to the user in the form of on-screen or hardcopy computer output; these description are also contained in the documentation reports (5,6,7). It is recommended that the novice or intermediate user review these to gain an appreciation of the involved hydrodynamic mixing processes.

3.6 Simulation Elements of CORMIX: Flow Prediction

Once a flow has been classified, CORMIX assembles and executes a sequence of appropriate hydrodynamic simulation m odules in the program element HYDRO1, 2 or 3. HYDRO consists of: (a) control programs or "protocols" for each hydrodynamic flow classification and (b) a large number of subroutines or "simulation modules" corresponding to the particular flow processes, and their associated spatial regions, that occur within a given flow classification. The simulation modules are based on buoyant jet similarity theory, buoyant jet integral models, ambient diffusion theory, and stratified flow theory, and on simple dimensional analysis, as described elsewhere (5,6,7,8). The basic tenet of the simulation methodology is to arrange a sequence of relatively simple simulation m odules which, when executed together, predict the trajectory and dilution characteristics of a complex flow. Each of the simulation models uses the final values of the previous module as "initial conditions".22 3.7 CORMIX Output Features: Design Summary and Iterations

In addition to the narrative feedback during user input, the CORMIX system provides three types of output on-screen or in print: a) CORMIX Session Report that is a narrative summary, mostly for regulatory evaluation, of all discharge input data and global plume features, including compliance with mixing zone regulations, b) CORMIX1, 2 or 3 Prediction File that is a detailed listing of all plume properties as predicted by the Fortran program, and c) CMXGRAPH Plots representing plan, side, and trajectory views and concentration distribution of the predicted plume.

3.7.1 CORMIX Session Report Region of Interest (ROI): The ROI is a SUM is the final program element that user defined region of the receiving water summarizes the hydrodynamic simulation results body where mixing c onditions are to be for the case under consideration. The output in analyzed. It is specified as the maximum the CORMIX Session Report is arranged in four analysis distance in the direction of mixed groups: effluent flow and is particularly important

(1) Site summary gives the site identifier exist or when information over a larger information, discharge and ambient environment area is of interest. data, and discharge length scales.

(2) Hydrodynamic simulation and mixing zone on toxic dilution zone criteria, regulatory mixing summary lists conditions at the end of the near- zone criteria, stagnant ambient environment field region (NFR), regulatory mixing zone (RMZ) information, and region of interest criteria. conditions, toxic dilution zone (TDZ) conditions, region of interest (ROI) conditions, upstream (4) Design recommendations section contains intrusion information, bank attachment locations, design suggestions in three general areas for and a passive diffusion mixing summary. Users improving initial dilution. These incl ude: (a) should be cognizant of the four major zone geometry variations in discharge port design, (b) definitions, and associated acronyms, intr oduced sensitivity to ambient conditions, and (c) process above and defined as follows: variations in discharge flow characteristics. The user is given guidance on the potential changes Near-Field Region (NFR): The NFR is simply the zone of strong initial mixing, corresponding to the "near-field" processes discussed in Chapter II. It has no regulatory implication whatsoever. However, the information on size and mixing conditions at the edge of the NFR Different options for iteration exist on the iteration is given as a useful guide to the discharge designer because mixing in the NFR is usually sensitive to design conditions, and therefore somewhat controllable. A notable exception is the effluent discharge into very shallow flow-limited streams where the actual discharge port design detail may have little bearing on instream concentrations.

Regulatory Mixing Zone (RMZ): The RMZ corresponds to either: (1) the applicable mixing zone regulation with specified size dimensions, or (2) a preliminary proposal for a mixing zone (see Section 2.2.4 (ii) ).

Toxic Dilution Zone (TDZ): The TDZ corresponds to the EPA's definition of where toxic chemical concentrations may exceed the CMC value (see Section 2.2.3).

when legal mixing zone restrictions do not

(3) Data analysis section presents further details

in mixing conditions from varying parameter values within these groups.

Finally, SUM is also used as an interactive loop to guide the user back to DATIN to alter design variables and perform sensitivity studies.

menu depending on what input data changes are to be made. The importance of performing an ample number of CORMIX iterations cannot be sufficiently stressed. To obtain a design that23 adequately meets water quality and engineering construction objectives, it is necessary to get a feel for the physical situation and its sensitivity to design changes through repeated system use.

3.7.2 CORMIX1, 2 or 3 Prediction File

The CORMIX1, 2 or 3 Prediction File is a detailed listing of all simulation input data as well as the predicted plume properties (plume s hapes and concentration distributions) arr anged by the individual flow modules that form part of the simulation. Additional information, such as encounter of local mixing zone regulations, plume contact with bottom or shoreline, etc., are listed in the output. Detailed output features are discussed in Chapter V.

3.7.3 CMXGRAPH Plots

The post-processing graphics package CMXGRAPH can be exercised flexibly by the user at different stages: directly after a CORMIX case prediction for an initial evaluation of the design case, or later to inspect or prepare plots for an earlier design case, or outside the CORMIX system to plot any plume predicted by CORMIX or CORJET. The user can view different views of the plume, with scaling and zooming possibilities. Finally, hardcopy printouts can be prepared through a direct print-screen option or by writing to a Postscript file. Details of the graphics feature are discussed in Chapter V.

3.8 Post-Processor Models CORJET and FFLOCATR: Input and Output Features to restore normal operations. A bootable floppy

The near-field jet integral model CORJET command FORMAT a:/S. and the far-field plume locator model FFLOCATR can be exercised both within the CORMIX The CORMIX must be installed on a hard system, with guided input data assembly, or disk drive. The directory structure of CORMIX separately, with a simple Fo rtran input file. In (Table 3.1) is fixed; it gets set up during the both cases, only limited data are needed. installation process; and it consists of a Chapter VI provides a detailed discussion of the subsystem root directory, called "CORMIX", and data requirements. six sub-directories. Complete installation

The output from these models is displayed distribution diskette. on-screen or as a printed file. Furthermore, CORJET output can also be plotted with the Depending on computer configuration, a CMXGRAPH program (see Section 5.3). typical CORMIX session for one 3.9 Equipment Requirements, System Installation and Run Times

The minimum recommended hardwareconfiguration required for CORMIX is an IBMDOS compatible microcomputer with: (a) a minimum of 550Kb of available RAM memory, (b) approximately 3Mb of hard disk space, (c) DOS 3.3 or higher operating system, and (d) a minimum 80386 with math co-processor to provide acceptable performance, especially with plume graphics display. The system will run on systems with less advanced processors, however simulation times can be long.

The RAM memory requirement of CORMIX may present an obstacle to many users because the configuration requirements of many commercial applications packages and the installation of memory resident software, or running DOS from windows, frequently reduce available RAM memory to less than 550Kb. The amount of available RAM memory can be determined with the DOS command CHKDSK. Although there are numerous approaches for increasing the size of a computer's available RAM memory, the simplest way is "boot" the computer from a floppy "system" disk that contains no AUTOEXEC.BAT or CONFIG.SYS files which consume additional memory. This should be done just prior to beginning an analysis session since it will temporary disable programs that consume RAM memory. The CONFIG.SYS file should allow the number of open files to be set to at least 20 by including the line statement "files=20". At the completion of the analysis session, the computer should be "booted" from the hard drive

system disk can be created with the DOS

instructions are available with the CORMIX

discharge/ambient condition may take less than 524 minutes for an Pentium-based computer to about the numerical simulation routines in HYDROn 20 minutes for an 80286-based computer if all may take up to 10 minutes to converge on necessary input data is at hand. In some unusual Pentium-based systems. cases (such as attached flow classes, e.g. H1A5)

Table 3.1 Directory Structure

CORMIX Version 3.1 June 1995, Version 3.2 September 1996

Directory Name Comments

CORMIX system root directory; contains VP-Expert system files, the

CORMIX\DATA contains cache "fact" files exported from knowledge base

CORMIX\EXE contains Fortran hydrodynamic simulation programs

CORMIX\KBS contains all knowledge base programs (*.kmp or *.kbs)

CORMIX\POST contains three post-processor programs CORJET,

CORMIX\POST\CJ contains CORJET numerical prediction files (fn.CJT) and

CORMIX\POST\FF contains FFLOCATR cumulative discharge input data files (*.FFI) and prediction files (fn.FFX)

CORMIX\SIM contains simulation results (Fortran files "fn.CXn", where n =

CORMIX\SIM\CXn contains simulation data files for each subsystem n (cache files "fn.CXC" and record keeping file "summary")

CORMIX\TEXT contains all user-requested advice files and flow descriptions knowledge base program CORMIX.kmp or kbs (system driver), and the start-up batch file CMX.bat, and several other batch files to be used for starting up CORJET, CMXGRAPH, and FFLOCATR when used independently

programs

HYDROn and file manipulation programs (*.exe)

CMXGRAPH, and FFLOCATR

graphical postscript files (fn.Pvn, where v = view type, and n = 0 to 9)

1,2,3, and fn = user designated filenames) and graphical postscript files (fn.Pvn, where v = view type, and n = 0 to 9)

(*.txt)25 

## IV CORMIX Data Input

4.1 General Aspects of Interactive Data Input R egular CORMIX versus FAST-CORMIX:

All CORMIX data input occurs interactively speed is set to "R egular CORMIX". In this mode in response to system prompts and is entirely the user will see detailed input questions with guided by the system. The user is automatically ample expl anations for each variable. Also there prompted for a complete specification of: will be opportunities to consult advice sections. It site/case descriptions, ambient conditions, is recomm ended that the novice user employ this discharge characteristics, and regulatory defini- m ode for about a dozen or so CORMIX sessions tions. The data for each of these four topical until he/she has become thoroughly familiar with areas are called input data sequences herein. Questions are asked in plain English. Advice menu options within the program are available to provide help on how to prepare and enter data values when clarification of the system prompts is needed. The contents of these are also available in the documentation reports (5,6,7). Upon in its initial installation the CORMIX system

the system. The advanced user can switch to the "FAST-CORMIX" mode in which only short questions are asked, thereby greatly accelerating data input and compacting it on screen. Certain advice section are not available. The differences are illustrated in the following:

Examples of three questions asked in Regular CORMIX :
1) Do you want detailed ADVICE on how to specify the ambient density stratification? [no] [yes]
2) Can the ambient density be considered 'UNIFORM' th roughout the water column,

or is there a 'NON-UNIFORM' vertical density stratification? As practical guideline, uniformity can be assumed if the vertical density variation between top and bottom is limited to 0.1 kg/m^3 or the temperature variation to 1 degC. [uniform] [non-uniform]
3) What is the WIDTH of the channel in the vicinity of the discharge (m)?

Corresponding questions in FAST-CORMIX :
1) <Question not asked>

2) AMBIENT DENSITY? [uniform] [non-uniform]
3) Channel WIDTH (m)?

Data can be entered in an open format without concern for letter case or decimal placement. The only constraint is that the following characters may not be entered in response to any question: + = { } , < > ' " / \ ; The system checks data entries for consistency with question type (e.g. an alphabetic character for water depth), obvious physical errors (e.g. a negative l ength), possible inconsistencies with previous entries (e.g. an angular value implying that a port points directly back to the26 shoreline) and situations outside the ranges of analysis to verify that all necessary data are model applicability. Inconsistency with question available. type and obvious physical errors require immediate re-entry while possible inconsistencies with previous entries lead to a warning label and the opportunity for later correction. Entries specifying situations outside the ranges of model applicability usually require the re-entry of the entire data segment.

Warning: No attempt should be made to alter input data by manipulating any of the data files that are used by the HYDROn Fortran programs and execute these programs separately without using the VP-Expert segments DATIN, PARAM, and CLASS. Because of the inherent error and compatibility checking of input data within these program segments, unreliable prediction may result if they are by-passed!

As discussed in Chapter III, data input occurs in three or four program segments that load automatically. At the end of each data sequence (usually of the order of 5 to 20 items long) the entire sequence is displayed and the user is requested to accept or not accept the sequence. If it is not accepted, i.e. an error has been made, the user has another opportunity for entering the sequence. If an error is detected earlier there is no way of correcting immediately, it is best then to give a short answer (e.g. the value of 1) to all remaining questions and thus quickly move to the end of the sequence for the re-start opportunity.

Due to the similarity of data entry, a common description is given for all input data sequences, except discharge data to which a separate subsection for each CORMIXn subsystem is devoted below. Further guidance on data specification can be obtained from examining the case studies in the Appendices and from the documentation m anuals (5,6,7). Following the discussion of input data sequences, units of measure conversion factors and checklists for input preparation are presented.

All the data input requirements of CORMIX are included in the Checklist for Data Preparation (see following page) that can be photocopied by the reader for future multiple use. The checklist aids in the assembly and preparation of this data prior to beginning an 4.2 Site/Case Identifier Data

The first input data sequence determines basic information needed for the program to operate. These include: a two-part identifier for labeling output and a computer file name.

It is necessary to specify three site/case labels that facilitate the rapid identification of printed output and aid in good record-keeping. The system provides for one label called SITE NAME (e.g. Blue River), another called DESIGN CASE (e.g. 7Q10-low-flow, or High-velocity-port).

The user needs to supply a DOScompatible FILE NAME, up to eight characters long, and without extension (e.g. sdif7q10). CORMIX will use that user-specified file name fn

, and create, transfer, or store intermediate or final data files with that same file name, but with different extensions. The most important of these are the two output data files, SIM\ fn .CXn and SIM\CXn\ fn .CXC, where n = 1, 2 or 3, which are discussed further in Chapter V.

4.3 Ambient Data

Ambient conditions are defined by the geometric and hydrographic conditions in the vicinity of the discharge. Due to the significant effect of boundary interactions on mixing processes, the ambient data requirements for the laterally bounded and unbounded analysis situations are presented separately in the discussions below. CORMIX analyses, as all mixing zone evaluations, are usually carried out under the assumption of steady-state ambient conditions. Even though the actual water environment is never in a true steady-state, this assumption is usually adequate since mixing processes are quite rapid relative to the time scale of hydrographic variations. In highly unsteady tidal reversing flows the assumption is no longer valid and significant concentration build-up can occur. CORMIX will assess this situation and compute some re-entrainment effects on plume behavior. The data requirements for that purpose are discussed in the Section 4.3.3. Following are discussions on ambient

## HA 2 

## HA 1 

## QA 2 

## QA 1 3 5

28 density specification and on wind effects. cross-sections, it may r equire more judgment and

CORMIX requires that the actual cross- better feel on the sensitivity of the results to the section of the ambient water body be described assumed cross-sectional shape. by a rectangular channel that may be bounded laterally or unbounded. Furthermore, that In any case, the user is advised to channel is assumed to be uniform in the consider the following comments: downstream direction, following the mean flow of the actual water body that may be non-uniform or a) Be aware that a particular flow condition meandering. The process of describing a such as a river discharge is usually associated receiving water body's geometry with a with a certain water surface elevation or "stage."rectangular cross-section is herein called Data for a stage-discharge relationship is norschematization

.
Additional aids exist for the CORMIX user for interpreting plume behavior in the far-field of actual non-uniform (winding or meandering) flowsin rivers or estuaries (see Section 6.2 for the postprocessor option FFLOCATR).

The first step towards specifying the ambient conditions is to determine whether a receiving water body should be considered "bounded" or "unbounded." To do this, as well as answer other questions on the ambient geometry, it is usually necessary to have access to cross-sectional diagrams of the water body. These should show the area normal to the ambient flow direction at the discharge site and at locations further downstream. If the water body is constrained on both sides by banks such as in rivers, streams, narrow estuaries, and other narrow watercourses, then it should be considered "bounded." However, in some cases the discharge is located close to one bank or shore while the other bank is for practical purposes very far away. When interaction of the effluent plume with that other bank or shore is impossible or unlikely, then the situation should be considered "unbounded." This would include discharges into wide lakes, wide estuaries, and coastal areas.

4.3.1 Bounded Cross-Section

Both geometric (bathymetric) and hydrographic (ambient discharge) data should be used fordefining the appropriate rectangular crosssection. This schematization may be quite evident for well-channeled and regular rivers or artificial channels. For highly irregular perhaps several iterations of the analysis to get a

mally available from a USGS office; otherwise it can be obtained from a separate hydraulic analysis or from field measurements.

In the simplest case of a river flow, if river depth is known for a certain flow c ondition (subscript 1 in the following) corresponding perhaps to the situation at the time of a field study, then the depth for a given design (e.g. low) flow (subscript 2) can be predicted from Manning's equation

in which QA is the ambient river flow and HA the mean ambient depth. This approach assumes that the both the ambient width and frictional characteristics of the channel (i.e. Manning's n) remain approximately the same during such a stage change.

b) For the given stage/river discharge combination to be analyzed, assemble plots showing the cross-sections at the discharge and several downstream locations. Examine these to determine an "equivalent rectangular cross-sectional area." Very shallow bank areas or shallow floodways may be neglected as unimportant for effluent transport. Also, more weight should be given to the cross-sections at, and close to, the discharge location since these will likely have the greatest effect on near-field processes. Figure 4.1a provides an example of the schematization process for a river or estuary cross-section.

### 29 Figure 4.1: Examples of the schematization process for preparing CORMIX input data on ambient cross-sectional conditions

## f 8 g n 2


## HA 1/3

30 c) The input data values for surface width The simulation of stagnant conditions (BS) and (average) depth (HA) should be determined from the equivalent rectan g ular crosssectional area. When ambient dischar g e and ambient velocity data are available, the reasonableness of the schematization should be checked with the continuity relation. It specifies that ambient dischar g e equals velocity times cross-sectional area, where the area is g iven by the product of avera g e width and depth.

The discussion of the cumulative dischar g e method (see Section 6.2 and Fi g ure 6.2 for an illustration) will provide further perspective on the choice of these variables.

d) CORMIX also requires specification of the actual water depth (HD) in the g eneral dischar g e location to describe local bathymetric Darcy-Weisbach friction factor f , must be features. A check is built in allowin g the local specified. Friction values are useful for depth HD not to differ from the schematized applications in laboratory studies. If Mannin g 's n

avera g e depth HA by more than +/- 30%. This is g iven, as is preferable for field cases, CORMIX restriction is included to prevent CORMIX misuse internally converts it to an f friction value usin g the in several dischar g e/ambient combinations followin g equation involvin g stron g ly non-uniform channels. Alternative schematizations can be explored by the user to work around the restriction. The choice for these alternatives may be influenced somewhat by the expected plume pattern. As an example, Fi g ure 4.1b illustrates a small buoyant dischar g e that is located on the side slope of a deep reservoir and that is risin g upward. In this situation, the correct representation of the deeper mean reservoir depth is irrelevant for plume predictions. Althou g h the illustration is for an unbounded example, the comments on choice of HA apply here, too.

When schematizin g HA and HD in hi g hly non-uniform conditions, HD is the variable that usually influences near-field mixin g , while HA is important for far-field transport and never influences the near-field.

e) The ambient discharge (QA) or mean ambient velocity (UA) may be used to specify the ambient flow condition. Dependin g which is specified, the pro g ram will calculate and display the other. The displayed value should be checked to see whether it is consistent with schematizations and continuity principles discussed above. should usually be avoided. If zero or a very small value for ambient velocity or dischar g e is entered, CORMIX will label the ambient environment as sta g nant. In this case, CORMIX will predict only the near-field of the dischar g e, since steady-state far-field processes require a mean transport velocity. Althou g h sta g nant conditions often, but not necessarily always, represent the extreme limitin g case for a dilution prediction, a real water body never is truly sta g nant. Therefore, a more realistic assumption for natural water bodies would be to consider a small, but finite ambient crossflow.

f) As a measure of the rou g hness characteristics in the channel the value of Manning's n , or alternatively of the

in which g = 9.81 m/s . 2

The friction parameters influence the mixin g process only in the final far-field diffusion sta g e, and do not have a lar g e impact on the predictions. Generally, if these values can be estimated within +/-30%, the far-field predictions will vary by +/-10% at the most. The followin g list is a brief g uide for specification of Mannin g 's n values; additional details are available in hydraulics textbooks (e. g . 24).

g ) The channel appearance can have an effect on the far field mixin g by increasin g turbulent diffusivity for the passive mixin g process, but will not si g nificantly affect near-field mixin g . Three channel appearance types are allowed in CORMIX. Type 1 are fairly strai g ht and uniform channels. Type 2 have moderate downstream meander with a non-uniform channel. Type 3 are stron g ly windin g and have hi g hly irre g ular downstream cross-sections.31 Channel type Manning's n Smooth earth channel, no weeds 0.020 Earth channel, some stones and weeds 0.025 Clean and straight natural rivers 0.025 - 0.030 Winding channel, with pools and shoals 0.033 - 0.040 Very weedy streams, winding, overgrown 0.050 - 0.150 Clean straight alluvial channels 0.031 d 1/6 (d = 75% sediment grain size in feet)

unavailable, data or estimates of the vertically

4.3.2 Unbounded Cross-section determine the cumulative cross-sectional area

Both hydrographic and geometric discharge cross-section. For each of the information are closely linked in this case. The subsequent downstream cross-sections, mark the following comments apply: position where the cumulative cross-secti onal

a) From lake or reservoir elevation or tidal cross-section. Then proceed as discussed in the stage data, determine the water depth(s) for the preceding paragraph. receiving water condition to be analyzed.

b) For the given receiving water condition to be analyzed, assemble plots showing water depth as a function of distance from the shore for the discharge location and for several positions downstream along the ambient current direction.

c) If detailed hydrographic data from field surveys or from hydraulic numerical model calculations are available, determine the

" cumulative ambient discharge " from the shore to the discharge location for the discharge cross-section. For each of the subsequent downstream cross-sections, determine the distance from the shore at which the same cumulative ambient discharge has been attained. Mark this position on all cross-sectional profiles. Examine the vertically averaged velocity and the depth at these positions to determine typical values for the ambient depth (HA) and ambient velocity (UA) input specifications. The conditions offshore from the discharge exit. It does not at, and close to, the discharge location s hould be describe the c onditions immediately in front of the given the most weight. The distance from the shore (DISTB) for the outfall location is typically specified as the cumulative ambient discharge divided by the product UA times HA.

When detailed hydrographic data are the ambient roughness characteristics as averaged velocity at the discharge location can be used to specify HA, UA, and DISTB. First,

from the shore to the discharge location for the

area has the same value as at the discharge

d) The specification of the actual water depth at the submerged discharge location (HD) in CORMIX1 and 2 is governed by considerations that are similar to those discussed earlier for bounded flow situations discussed above. Figure 4.1b shows an illustration of the schematization for a small buoyant discharge located on the side slope of a deep reservoir. The plume is expected to rise upward and stay close to one shore, with bottom contact and vertical mixing not expected. In this situation, no emphasis on replicating the mean reservoir depth and the actual width is necessary. However, care must still be taken to specify an ambient mean velocity that is: (a) characteristic of the actual reservoir and (b) not determined using the reduced depth assumption.

The specification of HD for CORMIX3 is dictated by the depth condition some distance

discharge channel exit. When in doubt, set HD simply equal to HA in the CORMIX3 case.

e) Either Manning's n or the DarcyWeisbach friction factor f can be specified for

### 32 described previously for the bounded case (see above). If the unbounded case represents a large lake or coastal area, it is often preferable to use the friction factor f. Typical f values for such open water bodies range from 0.020 to 0.030, with larger values for rougher conditions.

4.3.3 Tidal Reversing Ambient Conditions

When predictions are desired in an unsteady ambient flow field, information on the tidal cycle must be supplied. In general, estuaries or coastal waters can exhibit considerable complexity with variations in both velocity magnitude, direction and water depth. As an example, Figure 4.2 shows the time history of tidal velocities and tidal height for a mean tidal cycle at some site in Long Island Sound. The tidal height varies between mean Low Water (MLW) and Mean High water (MHW).

The tidal velocity changes its direction twice during the tidal cycle at times called slack tide. One of these times occurs near, but is not necessarily coincident with, the time MLW and is referred to as Low Water Slack (LWS). The slack period near MHW is referred to as High Water Slack (HWS). The rate reversal (time gradient of the tidal velocity) near these slack tides is of considerable importance for the concentration build-up in the transient discharge plume, as tidal reversals will reduce the effective dilution of a discharge by re-entraining the discharge plume remaining from the previous tidal cycle (8). Hence, CORMIX needs some information on the ambient design conditions relative to any of the two slack tides.

Figure 4.2: Example of tidal cycle, showing stage and velocity as a function of time after Mean High Water (MHW)33 The tidal period (PERIOD) must be supplied; in most cases it is 12.4 hours, but in considered as uniform or as non-uniform within some locations it may vary slightly. The the water body, and in particular within the maximum tidal velocity (UAmax) for the location must be specified; this can usually be taken as the average of the absolute values of the two actual maxima, independent of their direction. A neglected. For uniform conditions, the average CORMIX design case consists then of an instantaneous ambient condition, before, at or after one of the two slack tides. Hence, the analyst must specify the time (in hours) before, When conditions are non-uniform, at, or after slack that defines the design condition, followed by the actual tidal ambient velocity (UA) at that time. The ambient depth conditions are t hen those corresponding to that time. In general, tidal simulations should be repeated for several time intervals (usually hourly or two-hourly intervals will suffice) before and after slack time to determine plume characteristics in unsteady ambient conditions.

Strongly unsteady conditions can alsooccur in other environments, such as in windinduced current reversals in shallow lakes or coastal areas. In this case, any typical reversal period can be analyzed following an approach similar to the above.

4.3.4 Ambient Density Specification

Information about the density distribution in the ambient water body is very important for the correct prediction of effluent discharge plume behavior. CORMIX first inquires whether the ambient water is fresh water or non-fresh (i.e. brackish or saline). If the ambient water is fresh and above 4 C, the system provides the option of o entering ambient temperature data so that the ambient density values can be internally computed from an equation of state. This is the recommended option for specifying the density of fresh water, even though ambient temperature per se is not needed for the analysis of mixing conditions. In the case of salt water c onditions, Figure 4.3 is included as a practical guide for specifying the density if "salinity values " in partsper-thousand (ppt) are available for the water body. Typical open ocean salinities are in the range 33 - 35 ppt.

The user then specifies whether the ambient density (or temperature) can be

expected plume regions. As a practical guide, vertical variation in density of less than 0.1 kg/m 3 or in temperature of less than 1 C can be o

ambient density or average temperature must be specified.

CORMIX requires that the actual measured vertical density distribution be approximated by one of three schematic stratification profile types illustrated in Figure 4.4. These are: Type A, linear density profile; Type B, two-layer system with constant densities and density jump; Type C, constant density surface layer with linear density profile in bottom layer separated by a density jump. Corresponding profile types exist for approximating a temperature distribution when it is used for specifying the density distribution.

Note: When in doubt about the specification of the ambient density values it is reasonable to first simplify as much as possible. The sensitivity of a given assumption can be explored in subsequent CORMIX simulations. Furthermore, if CORMIX indicates indeed a flow configuration (flow class) with near-field stability, additional studies with the post-processor option CORJET (see Section 6.1) can be performed to investigate any arbitrary density distribution

. After selecting the stratification approximation to be used, the user then enters all appropriate density (or temperature) values and pycnocline heights (HINT) to fully specify the profiles. The pycnocline is defined as zone or level of strong density change that separates the upper and lower layers of the water column. The program checks the density specification to insure that stable ambient stratification exists (i.e. the density at higher elevations must not exc eed that at lower elevations).

Note that a dynamically correct approximation of the actua ldensity distribution should keep a balance between over-and under-estimationof the actual data similar to a best-fit in regression analysis. If simulation results indicate internal plume trapping, then it is

### 34 Figure 4.3: Diagram for density of seawater as a function of temperature and salinity

Figure 4.4: Different approximations for representing the ambient density stratification35 desirable to test --through repeated use of for non-circular shaped ports) ( Note: The CORMIX-- different approximations (i.e. with specification of the port dimension s hould account different stratification types and/or parameter for any contraction effects that the effl uent jet may values) in order to evaluate the sensitivity of the experience upon leaving the port/nozzle!) , (d) resulting model predictions.

4.3.5 Wind speed

When specifying the wind speed (UW) at design conditions, it should be kept in mind that the wind is unimportant for near-field mixing, but may critically affect plume behavior in the far-field. This is especially important for heated discharges in the buoyant spreading regions. Wind speed data from adjacent meteorological stations is usually sufficient for that purpose.

The following guidelines are useful when actual measured data are not available. The typical wind speed categories measured at the 10 m level are: --- breeze (0-3 m/s) --- light wind (3-15 m/s) --- strong wind (15-30 m/s)

If field data are not available, consider using the recommended value of 2 m/s to represent conservative design conditions. An extreme low value of 0 m/s is usually unrealistic for field conditions, but useful when comparing to laboratory data. A wind speed of 15 m/s is the maximum value allowed in CORMIX.

4.4. Discharge Data: CORMIX1

Figure 4.5a is a definition sketch giving the geometry and flow characteristics for a submerged single port discharge within the schematized cross-section.

4.4.1 Discharge Geometry

To allow the establishment of a reference coordinate system and orient the discharge to that reference, CORMIX1 requires the specification of 6 data entries. These specifications are illustrated in Figure 4.5a and include: (a) location of the nearest bank(i.e. left or right) as seen by an above restrictions, Section 7.4 of D oneker and observer looking downstream in the direction of Jirka (5) contains a number of hints on how to the flow, (b) distance to the nearest bank (DISTB) , (c) port radius (or cross-sectional area height of the port (H0) center above the bottom, (e) vertical angle of discharge (THETA) between the port centerline and a horizontal plane, and (f) horizontal angle of discharge (SIGMA) measured counterclockwise from the ambient current direction (x-axis) to the plan projection of the port centerline. Angle THETA may range between -45 and 90 . As examples, o o the vertical angle is 90 for a discharge pointing o vertically upward, and it is 0 for a horizontal o discharge. Angle SIGMA may range between 0 o and 360 . As examples, the horizontal angle is o 0 (or 360 ) when the port points downstream in

o o the ambient flow direction, and it is 90 , when the o port points to the left of the ambient flow direction.

In order to prevent an inappropriate system application, CORMIX1 checks the specified geometry for compliance with the three criteria illustrated in Figure 4.5b. These are: (a)the port height (H0) value must not exceed onethird of the local water depth (HD) value, (b) the port diameter value must not exceed HD's value for near-vertical designs, and one-third of HD's value for near-horizontal designs, and (c) the pycnocline value must be within the 40 to 90 percent range of HD's value. The port height restriction results from the fact that CORMIX1 only applies to submerged discharge applications.

In ordinary design practice, submerged implies a discharge close to the bottom, and not anywhere within the main water column or near the water surface. The port diameter restriction excludes very large discharge diameters relative to the actual water depth since these are unrealistic and/or undesirable. The distance separating the upper and lower layers of the ambient density profile type B or C is restricted in order to prevent: (a) discharges into the upper layer or (b) an unrealistically thick plume relative to a thin upper layer. For those few extreme situations that would normally be limited by the

conduct these difficult analyses; only advanced users should attempt these techniques

.

### 36 Figure 4.5: CORMIX1 discharge geometry and restrictions37 4.4.2 Port Discharge Flow located at the center (mid-point) of the diffuser

For discharge characteristics, CORMIX1 starts at the shore; then the origin is located requires the specification of 3 data entries. These directly at the shore. specifications include: (a) the discharge flow rate (Q0) or discharge velocity (U0) , (b) the discharge density or discharge temperature for an essentially freshwater discharge, and (c) the discharge concentration of the material of interest. The Q0 and U0 variables are related through the port cross-sectional area and the program computes and displays the alternate value allowing for user inspection and verification. For a freshwater discharge, discharge density can be directly related to temperature via an equation of state since the addition of any pollutant or tracer has negligible effect on density. horizontally; and (c) the alternating diffuser

The specification of the pollutant in the horizontal direction. In the latter case, the ports effluent is described in Section 4.7 below. may point more or less horizontally in an

4.5 Discharge Data: CORMIX2

A generalized definition sketch showing the geometry and flow characteristics for a typical multiport diffuser installation is provided in Figure 4.6a. Due to the great number of complexities which may rise in describing an existing or proposed diffuser design, a few definitions are introduced prior to discussing actual data requirements of CORMIX2.

A multiport diffuser is a linear structure consisting of many more or less closely spaced ports or nozzles which inject a series of turbulent jets at high velocity into the ambient receiving water body. These ports or nozzles may be connected to vertical risers attached to an underground pipe or tunnel or they may simply be openings in a pipe lying on the bottom.

The diffuser line (or axis) is a line connecting the first port or nozzle and the last port or nozzle. Generally, the diffuser line will coincide with the connecting pipe or tunnel. CORMIX2 will assume a straight diffuser line . If the actual diffuser pipe has bends or directional changes it bank (DISTB) , (c) average diameter (D0) of the must be approximated by a straight diffuser line.

The diffuser length is the distance from from 1 for well rounded ports --usual value-- down the first to the last port or nozzle. The origin of to 0.6 for sharp-edged orifices), (e) average the coordinate system used by CORMIX2 is line. The only exception is when the diffuser line

CORMIX2 can analyze discharges from the three major diffuser types used in common engineering practice. These are illustrated in Figure 4.7 and include: (a) the unidirectional diffuser where all ports (or nozzles) point to one side of the diffuser line and are oriented more or less normally to the diffuser line and more or less horizontally; (b) the staged diffuser where all ports point in one direction generally following the diffuser line with small deviations to either side of the diffuser line and are oriented more or less

where the ports do not point in a nearly single

alternating fashion to both sides of the diffuser line or they may point upward, more or less vertically.

4.5.1 Diffuser Geometry

CORMIX2 assumes uniform discharge conditions al ong the diffuser line. This includes the local ambient receiving water depth (HD) and discharge parameters such as port size, port spacing and discharge per port, etc. If the actual receiving water depth is variable (e.g. due to an offshore slope), it should be approximated by the mean depth along the diffuser line with a possible bias to the more shallow near-shore conditions. Similarly, mean values should be used to specify variable diffuser geometry when it occurs.

To allow the establishment of a reference coordinate system and orient the discharge to that reference, CORMIX2 requires the specification of 13 data entries. These specifications are illustrated in Figure 4.6a and include: (a) location of the nearest bank (i.e. left or right) as seen by an observer looking downstream in the direction of the flow, (b) average distance to the nearest

discharge ports or nozzles, (d) contraction ratio for the port/nozzle is required (This can range

### 38 Figure 4.6: CORMIX2 discharge geometry and restrictions40 height of the port centers (H0) above the bottom, (f) average vertical angle of discharge (THETA) between the port centerlines and a horizontal plane (-45 and 90 ), (g)for the o unidirectional and staged diffusers only, the average horizontal angle of discharge (SIGMA) measured counterclockwise from the ambient current direction (x-axis) to the plan projection of the port centerlines (0 to 360 ), (h) approximate o straight-line diffuser length (LD) between the first and last ports or risers, (I) distance from the shore to the first and last ports or risers (YB1, YB2) of the diffuser line, (j) number of ports or risers and the number of ports per riser if risers are present, (k) average alignment angle (GAMMA) measured counterclockwise from the ambient current direction (x-axis) to the diffuser axis (0 to 180 ), and (l) for the unidirectional and o staged diffusers only, relative orientation angle (BETA) measured either clockwise or counterclockwise from the average plan projection of the port centerlines to the nearest diffuser axis (0 to 90 ). Note that CORMIX2 o always assumes a uniform spacing betweenrisers or between ports, and a round port crosssectional shape.

As examples of angle specifications, THETA is 0 degrees for a horizontal discharge and it is +90 degrees for a vertically upward discharge, SIGMA is 0 degrees (or 360 ) when o the ports point downstream in the ambient flow direction and it is 90 degrees when the ports point to the left of the ambient flow direction, GAMMA is 0 degrees (or 180 ) for a parallel diffuser and it o is 90 degrees for a perpendicular diffuser, and BETA is 0 degrees for a staged diffuser and it is 90 degrees for a unidirectional diffuser.

CORMIX2 performs a number of consistency checks to ensure the user does not make arithmetical errors when preparing and entering the above data and it also checks the specified geometry for compliance with three criteria to prevent an inappropriate system application. Figure 4.6b shows the imposed limits of system application for CORMIX2 which are: (a)the port height (H0) value must not exceed onethird of the local water depth (HD) value, (b) the the channel entry (HD0) and (e) bottom slope port diameter value must not exceed one-fifth of HD's value, and (c) the pycnocline value must be within the 40 to 90 percent range of HD's value. The restrictions are similar to those shown in Figure 4.5b for CORMIX1 with the exception of the diameter limit for each port.

4.5.2 Diffuser Discharge Flow

For discharge characteristics, CORMIX2 requires the specification of 3 data entries. These specifications include: (a) the total discharge flow rate (Q0) or discharge velocity (U0) , (b) the discharge density or discharge temperature for an essentially freshwater discharge, and (c) the discharge concentration of the material of interest. The Q0 and U0 variables are related through the total cross-sectional area of all diffuser ports and the program computes and displays the alternate value allowing for user inspection and verification.

The specification of the pollutant in the diffuser effluent is described in Section 4.7 below.

4.6 Discharge Data: CORMIX3

A definition sketch for the discharge geometry and flow characteristics for a buoyant surface discharge is provided in Figure 4.8. In general, CORMIX3 allows for different types of inflow structures, ranging from simple rect angular channels to horizontal round pipes that may be located at or near the water surface. In addition, three different configurations relative to the bank are allowed as illustrated in Figure 4.9. Discharge structures can be: (a) flush with the bank/shore, (b) protruding from the bank or (c) co-flowing along the bank.

4.6.1 Discharge Geometry

To allow the establishment of a reference coordinate system and orient the discharge to that reference, CORMIX3 requires the specification of up to 7 data entries. These specifications are illustrated in Figure 4.8 and include: (a) location of the nearest bank (i.e. left or right) as seen by an observer looking downstream in the direction of the flow, (b) discharge channel width (B0) of the rectangular channel , (c) discharge channel depth (H0) , (d) actual receiving water depth at

(SLOPE) in the receiving water body in the vicinity of the discharge channel, and (f) horizontal angle of discharge (SIGMA) measured counterclockwise from the ambient current direction (x-axis) to

### 41 Figure 4.8: CORMIX3 discharge channel geometry

### 42 Figure 4.9: Possible CORMIX3 discharge configurations of discharge channel relative to bank/shoreline43 the plan projection of the port centerline. In the The discharge concentration of the case of a circular discharge pipe , the (b) pipe diameter and (c) depth of bottom invert below the water surface (water surface to bottom edge of pipe) must be specified, respectively. In all cases, CORMIX3 assumes the discharge is being issued horizontally.

CORMIX3 uses the variable HD0 for the actual water depth just in front of the c hannel exit and requires an additional specification for the receiving water bottom slope, again in front of the exit, extending into the receiving water body. These details are important for identifying cases where plume attachment to the bottom can occur.

In the case of a circular pipe discharge CORMIX3 assumes the outlet is flowing full and that it is not submerged under the water surface by more than 1⁄2 of the outlet diameter. If the discharge outlet has an odd cross-sectional shape (e.g. a pipe flowing partially full) then it should be represented schematically as a rectangular outlet of the same cross-sectional coefficient of decay (positive number) or area and similar channel depth.

For open channel discharges, considerable care should be exercised when specifying discharge channel depth since this parameter is directly linked to the ambient receiving water depth (stage). This is especially important for tidal situations.

To prevent an inappropriate system application, CORMIX3 only allows for a discharge channel depth-to-width aspect ratio of 0.05 to 5. This prohibits the use of extremely oblong discharge geometry.

4.6.2 Discharge Flow
For discharge characteristics, CORMIX3 requires the specification of 3 data entries. These specifications include: (a) the total discharge flow rate (Q0) or discharge velocity (U0) , (b) the discharge density or discharge temperature for an essentially freshwater discharge, and (c) the discharge concentration of the material of interest. The Q0 and U0 variables are related through the channel cross-sectional area; the program computes and displays the alternate value allowing for user inspection and verification. material of interest (pollutant, tracer, or temperature) is defined as the excess concentration above any ambient concentration of that same material . The user can specify this quantity in any units. CORMIX1 predictions should be interpreted as computed excess concentrations in these same units. If no specific pollutant is under consideration, simply specify a discharge concentration of 100%.

4.7 Pollutant Data

CORMIX allows three types of pollutant discharges:

(a) Conservative Pollutant: The pollutant does not undergo any decay/growth processes.
(b) Non-conservative Pollutant: The pollutant undergoes a first order decay or growth process. One needs to specify the

growth (negative number) in units: /day (per day).

(c) Heated Discharge : The discharge will experience heat loss to the atmosphere in cases where the plume contacts the water surface. It is necessary to specify the discharge condition in terms of excess temperature ("delta T") above ambient in units degC , and the surface heat exchange coefficient in units W/m ,degC. Values of the 2 heat exc hange coefficient depend on ambient water temperature and wind speed. The following listing provides a guideline for the selection.

Typically, the near-field behavior is quite insensitive to the choice of these values, but it may affect the prediction results at greater distances in the far-field.

The discharge concentration (C0) of the material of interest (pollutant, tracer, or temperature) is defined as the excess concentration above any ambient background concentration of that same material . The user can specify this quantity in any units of concentration (e.g. mg/l, ppm, %, C). CORMIX o predictions should be interpreted as computed excess concentrations in these same units.44 SURFACE HEAT EXCHANGE COEFFICIENT (W/m , C) 2 o Values for a lightly heated, natural water surface (local excess temperatures 0 to 3 C) o

Ambient Water Wind Speed (m/s) Temp. ( C) 0 1 2 4 6 8 o

5 5 10 14 24 33 42 10 5 11 16 27 38 49 15 5 12 18 31 44 59 20 5 14 21 38 52 68 25 6 16 25 45 63 82 30 6 19 30 54 76 100

Ref: "Heat Disposal in the Water Environment", E.E. Adams, D.R.F. Harleman, G.H. Jirka, and K.D. Stolzenbach, Course Notes, R.M. Parsons Laboratory, Mass. Inst. of Techn., 1981.

If no pollutant data at all is available, it is occur at correct regulatory concentrations most convenient to specify C0 = 100 %. because they are interpreted as excess

In case of an ambient background concentration it is important to treat all pollutant related data items in a consistent fashion. This 4.8 Mixing Zone Data includes the specification of any regulatory values as discussed in Section 4.8 below. The user must indicate: (a) whether EPA's

Example: suppose the actual discharge whether an ambient water quality standard exists, concentration for a particular pollutant is (c) whether a regulatory mixing zone (RMZ) 100 mg/l, and values of CMC and CCC for definition exists, (d) the spatial region of interest the pollutant are 20 mg/l and 10 mg/l, (ROI) over which information is desired, and (e) respectively. If the background ambient number of locations (i.e. "grid intervals") in the concentration for the same pollutant is 4 ROI to display output details. Depending on the mg/l, the data entry to CORMIX would be responses to the above, several additional data for the discharge concentration = 96 mg/l, entries may be necessary as described in the for CMC = 16 mg/l, and for CCC = 6 mg/l, following paragr aphs. respectively. All concentration values listed in the diverse CORMIX output (see When TDZ definitions apply, the user Chapter V) must then be interpreted must also indicate the criterion maximum accordingly, and the actual concentration concentration (CMC) and criterion continuous values are computed by adding the concentration (CCC) which are intended to background concentration value. E.g. if protect aquatic life from acute and chronic effects, the CORMIX predicted value for one respectively. CORMIX will check for compliance particular point happens to be 13.6 mg/l, with: (a) the CMC standard at the edge of the then the total concentration value at that TDZ and (b) the CMC standard at the edge of the point would be 17.6 mg/l. Also, all RMZ, proving a RMZ was defined. See program mixing zone messages would Subsection 2.2.2 for additional discussion. plume concentrations above ambient.

toxic dilution zone (TDZ) definitions apply, (b)45 When a RMZ definition exists, it can be specified by: (a) a distance from the discharge location, (b) the cross-sectional area occupied by the plume, or (c) the width of the effluent plume.

The ROI, which is a user defined region where mixing conditions are to be analyzed, is specified as the maximum analysis distance in the direction of mixed effluent flow. The level of detail for the output data within the ROI and thus, for the entire hydraulic simulation, is established by specifying the number of grid intervals that will be displayed in the output files. This parameter's allowable range is 3 to 50 and the chosen value does not affect the accuracy of the CORMIX prediction, only the amount of output detail. A low value should be specified for initial calculations to minimize printout lengths while a large value might be desirable for final predictions to give enough resolution for plotting of plume dimensions. 4.9 Units of Measure

CORMIX uses the metric system of measurement. When data values are provided to the user in English units, these must be converted to equivalent metric measures. The list at the beginning of this manual gives the five metric dimensions used by CORMIX in the left column, and on the right, their equivalents in some common English units.

Pollutant concentrations can be entered in any conventional measure such as mg/L, ppb, bacteria-count, etc.

Considering the potential accuracy of CORMIX predictions, 3 to 4 significant digits are sufficiently accurate for most input data values as suggested in the above conversion list. The only exceptions are the ambient and effluent density values. These may require 5 significant digits, especially when simulating the discharge to an ambient density-stratified receiving water body.4647 

## V CORMIX Output Features

CORMIX is a highly interactive system and computation results and (c) flow class conveys information to the user through descriptions. The paragraphs within this Section qualitative descriptions and detailed quantitative aid in the interpretation of that information. numerical predictions. This output can be viewed on-screen in text mode or graphics mode, can be The program elements PARAM and directed to a printer, and is stored in subdirectory CLASS, in particular, provide essential CORMIX\SIM and CORMIX\SIM\CXn files. In information on the expected dynamic behavior of this chapter the label n = 1, 2 or 3 desi gnates the the discharge. By actively participating in the appropriate CORMIX subsystem. interactive process, the novice and intermediate

5.1 Qualitative Output: Flow Descriptions

After completion of the input data entry sequences, the system proceeds through the program elements following the flow chart displayed in Figure 3.1. In addition to the routine operational messages provided during program execution, important qualitative information is displayed on-screen about the ongoing analysis of the given ambient/discharge case. The three general types of descriptive information provided are: (a) descriptive messages, (b) length scale user can derive a substantial educational benefit and a technical appreciation of the physical aspects of initial mixing processes. Although advanced users may find some of the presented material somewhat repetitive, they should still consult the length scale computation results.

5.1.1 Descriptive Messages

These messages provide both physical information and insight into the logic reasoning employed by CORMIX. Three example descriptive messages are:

"The effluent density (1004.5 kg/m^3) is greater than the surrounding water density at the discharge level (997.2 kg/m^3). Therefore, the effluent is negatively buoyant and will tend to sink towards the bottom."

"STRONG BANK INTERACTION will occur for this perpendicular diffuser type due to its proximity to the bank (shoreline). The shoreline will act as a symmetry line for the diffuser flow field. The diffuser length and total flow variables are doubled (or approximately doubled, depending on the vicinity to the shoreline). All of the following length scales are computed on that basis."

"The specified two layer ambient density stratific ation is dynamically important. The discharge near field flow will be c onfined to the lower layer by the ambient density stratification. Furthe rmore, it may be trapped below the ambient density jump at the pycnocline."

The preceding example output highlights analysis c onditions. In some instances, the several features of CORMIX's descriptive provided information may be obvious to the user, messages. These include: (a) conveying basic while in others it may not, particularly for information about the involved mixing processes, situations involving li near ambient stratification. (b) using a careful terminology (e.g. "..tend to The use of a careful terminology is necessary sink.."), (c) describing key calculation because messages are presented as the analysis assumptions, and (d) alerting the user to sensitive proceeds and subsequent tests may alter, or48 amplify, initial results. For example, near-field local water depth (HD), this is an immediate instabilities, which are tested for late in the indication to the user that the crossflow is very analysis, can prevent an otherwise sinking plume. str ong, leading to complete bending of the 5.1.2 Length Scale Computations buoyant jet. If the reverse holds true, the

The program element PARAM computes is negligible, and the buoyant jet will strongly so-called " length scales " which represent important dynamic measures about the relative influence of certain hydrodynamic processes on effluent mixing. These calculated values are subsequently used in program element CLASS to identify the generic flow class upon which the hydraulic simulations will be based. This flow classification is accomplished through formal dynamic length scale analysis , which is a key aspect of the theoretical underpinnings for the CORMIX approach. The CORMIX documentation manuals (5,6,7) and related journal publications provide the theoretical background on length scale definitions and significance, their derivation from principles of dimensional analysis, and their use in the CORMIX flow classification approach.

Although flow classification is a formal process using criteria derived from theoretical studies and/or experimental data, a great deal can be deduced about the flow dynamics by comparing the calculated length scales to the actual physical measures of the ambient/discharge situation. Of greatest importance are comparison to such geometric measures as: the available water depth (HD), a pycnocline height (HINT) and the distance to the nearest bank (DISTB). The following discussion provides a brief explanation of the more important length scales and examples on how to make appropriate comparisons in a given application. Users are encouraged to make these comparisons. a) Single port discharges: Some important length scales relating to submerged round buoyant jets (CORMIX1) are described in Table 5.1. All of these scales are defined from an interplay of the momentum and buoyancy flux quantities of the discharge with each other or with the current velocity and stratification gradient variables.

As an example, consider a vertically discharging buoyant jet into an unstratified ambient receiving water. When both calculated L and L values are substantially less than the

m b crossflow may be so weak that its deflecting effect

interact (impinge) with the water surface. In the first instance, a situation as depicted in Figures 2.1b combined with Figure 2.1a will result, while in the second instance, a flow resembling Figures 2.2c or 2.2d may arise, depending on the relation of the two scales with each other.

As another example, consider a buoyant jet discharging into a linearly stratified ambient. If both L ' and L ’ both larger than the pycnocline m b height (HINT) and even the water depth (HA), thiswould be an indication that the existing stratification is so weak that it will not lead to any trapping of the effluent plume within the available vertical space.

By making such comparisons, users will gradually get a good feel for the behavior of the buoyant jet, and other mixing processes within the space constraints of the ambient environment. Those interested in design can quickly gain an appreciation of the length scale measures and their sensitivity to design choices. However, there are limitations to these simplistic comparisons because the "length scales" are by no means precise measurements for the influence of the different processes . As their name implies they should be taken only as "scale" estimates. The actual CORMIX classification scheme uses formal criteria when comparing the length scale measures with the geometric constraints or each other. b) Multiport diffusers: Some important length scales for multiport diffusers (CORMIX2) are described in Table 5.2. To a large extent, these scales have a similar meaning for the behavior of the plane buoyant jet as the earlier ones discussed for the round buoyant jet (Table 5.1). However, they are calculated differently because the CORMIX2 system uses the "equivalent slot diffuser" concept to model the overall dynamics of the submerged multiport diffuser (Section 3.1). Except for the immediate close-up zone before the individual jets merge (Figure 2.1d) this concept is a dynamically valid and accurate representation of multiport diffuser flows (6).49 Table 5.1 Length Scales for Single Port Submerged Discharges (Used in CORMIX1 and CORMIX2)

Jet/plume transition length scale L = M / J Mo o 3/4 1/2

interpretation: For combined buoyant jet flow, the distance at which the transition from jet to plume behavior takes place in a stagnant uniform ambient.

Jet/crossflow length scale L = M / u mo a 1/2

interpretation: In the presence of a crossflow, the distance of the transverse (i.e. across ambient flow) jet penetration beyond which the jet is strongly deflected (advected) by the cross flow. For a strictly co-flowing discharge (  = 0, ) = 0), the length of the region beyond which the flow is simply advected.

Plume/crossflow length scale L = J / u b oa 3 interpretation: The vertically upward or downward flotation distance beyond which a plume becomes strongly advected by crossflow.

Jet/stratification length scale L ' = M /  m o 1/4 1/4 interpretation: In a stagnant linearly stratified ambient, the distance at which a jet becomes strongly affected by the stratification, leading to terminal layer formation with horizontally spreading flows.

Plume/stratification length scale L ' = J /  b o 1/4 3/8 interpretation: In a stagnant linearly stratified ambient, the distance at which a plume becomes strongly affected by the stratification, leading to terminal layer formation with horizontally spreading flows.

_______________ Notes: M = U Q , kinematic momentum flux o oo J = g' Q , kinematic buoyancy flux

o oo Q = U a , source discharge volume flux

o oo a = port area

o u = ambient velocity

a U = port discharge velocity

o  = ambient buoyancy gradient

. g' = discharge buoyancy = g( ' - ' )/ '

o a oa

However, there are some exceptions and notable example is circulating motions induced in additional complexities to interpreting the two- shallow receiving waters due to intermediate-field dimensional slot length scales measures effects (Section 2.1.1). The immediate close-up described in Table 5.2. In addition to the z one before the indivi dual jets merge is also not predominately two-dimensional flow behavior, addressed by the two-dimensi onal length scales. some of the large scale dynamics of multiport Additional discussion of these and other diffusers may also be influenced by other scales peculiarities can be found elsewhere (6,18). depending on the overall diffuser flow pattern. A50 Table 5.2 Dynamic Length Scales for Multiport Diffuser (CORMIX2) in the Two-Dimensional "Slot" Discharge Representation

Slot jet/plume transition length scale 5 = m / j M oo 2/3

interpretation: For combined buoyant jet flow, the distance at which the transition from jet to plume behavior takes place in a stagnant uniform ambient.

Slot jet/crossflow length scale 5 = m / u m oa 2

interpretation: In the presence of a crossflow, the distance of the transverse (i.e. across ambient flow) jet penetration beyond which the jet is strongly deflected (advected) by the cross flow. For a strictly co-flowing discharge (  = 0, ) = 0), the length of the region beyond which the flow is simply advected.

Slot jet/stratification length scale 5 ' = m /  m o 1/3 1/3 interpretation: In a stagnant linearly stratified ambient, the distance at which a jet becomes strongly affected by the stratification, leading to terminal layer formation with horizontally spreading flows.

Slot plume/stratification length scale 5 ' = j /  b o 1/3 1/2 interpretation: In a stagnant linearly stratified ambient, the distance at which a plume becomes strongly affected by the stratification, leading to terminal layer formation with horizontally spreading flows.

Crossflow/stratification length scale 5 = u /  a a 1/2 interpretation: The vertically upward or downward floatation distance beyond which a plume becomes strongly advected by crossflow.

_______________ Notes: m = U q , kinematic momentum flux per unit length o oo j = g' q , kinematic buoyancy flux per unit length o oo q = U na /L , source discharge volume flux

o o oD a = port area

o u = ambient velocity

a U = port discharge velocity

o  = ambient buoyancy gradient

. g' = discharge buoyancy = g( ' - ' )/ '

o a oa n = total number of nozzles L = overall diffuser length

D

c) Buoyant surface jets: Someimportant length scales that describe the nearfield dynamics of buoyant surface jets discharging into unstratified receiving waters (CORMIX3) are listed in Table 5.3. These scales are defined in a similar manner to the submerged discharged cases but due to the discharge location at the surface, they have different interpretations. For example, L is compared to the channel width m (BS) instead of the local water depth as it was in submerged case examples; if it exceeds BS, the discharge will quickly interact with the opposing bank.51 Table 5.3 Dynamic Length Scales for Buoyant Surface Jets (CORMIX3) Discharging into Unstratified Receiving Water

Jet/plume transition length scale L = M / J Mo o 3/4 1/2

interpretation: For stagnant ambient conditions, the extent of the initial jet region before mixing changes over into an unsteady surface spreading motion.

Jet/crossflow length scale L = M / u mo a 1/2

interpretation: The distance over which a discharging jet intrudes into the ambient crossflow before it gets strongly deflected.

Plume/crossflow length scale L = J / u b oa 3

interpretation: A measure of the tendency for upstream intrusion for a str ongly buoyant discharge.

_______________ Notes: M = U Q , kinematic momentum flux o oo J = g' U , kinematic buoyancy flux

o oo Q = U a , source discharge volume flux

o oo a = channel cross-sectional area o u = ambient velocity

a U = channel discharge velocity

o g' = discharge buoyancy = g( ' - ' )/ '

o a oa

d) Tidal reversing flows: Additional length and time scales can be defined for unsteady flows in which the scale of influence of oscillating plume depends on the rate of velocity reversal change at slack tide (8,17). CORMIX will take the actual steady-state predictions and adjust their concentration values according to the time after reversal relative to the time scale T and u also limit their areal applicability relative to L . u 5.1.3 Description of Flow Classes

Program element CLASS, performs a rigorous classification of the given discharge/ambient situation into one of many generic flow classes with distinct hydrodynamic features. In a way, this amounts to identifying a general pictorial description of the expected flow configuration. Table 5.5 lists and describes the broad categories of flow classes available in CORMIX. CORMIX1, 2 and 3, consider 35, 31 and 11 distinct flow classifications, respectively. Each flow class identification consists of an alphanumeric label corresponding to the flow category and a number (e.g. MU2). Textdescriptions of the flow classes are available onscreen during the analysis and can printed from the files stored within sub-directory CORMIX\TEXT (Table 3.1). Pictorial illustrations of the flow classes can be found in Appendix A

. As an example, Figure 5.1 shows the pictorial illustration and text description for flow class S1, a case of an effluent that becomes trapped in ambient stratification. It is strongly recommended that novice or intermediate users scrutinize these materials to gain a qualitative understanding of the effluent flow's behavior.

### L u 

### M o 

### du a 

### /dt 1/3



### T u 

### M o 

### du a 

### /dt 1/4 1/6

52 Table 5.4 Dynamic Length and Time Scales for Discharges into Unsteady Tidal Reversing Flows

Jet-to unsteady-crossflow length scale

interpretation: A measure of the distance of the forward propagation into the ambient flow of a discharge during the reversal episode.

Jet-to unsteady-crossflow time scale

interpretation: a measure of the duration over which an effluent may be considered as discharging into stagnant water while the velocity field is reversing.

_______________ Notes: M = U Q , kinematic momentum flux o oo du /dt = time rate of reversal of ambient velocity (absolute value) a

Table 5.5 Flow Class Categories and Descriptions

CORMIX1: 35 flow classes Classes S: Flows trapped in a layer within linear stratification. Classes V,H: Positively buoyant flows in a uniform density layer. Classes NV,NH: Negatively buoyant flows in uniform density layer. Classes A: Flows affected by dynamic bottom attachment.

CORMIX2 : 31 flow classes Classes MS: Flows trapped in a layer within linear ambient stratification. Classes MU: Positively buoyant flows in a uniform density layer. Classes MNU: Negatively buoyant flows in uniform density layer.

CORMIX3 9 flow classes Classes FJ: Free jet flows without near-field shoreline interaction. Classes SA: Shoreline-attached discharges in crossflow.53 Classes WJ: Wall jets/plumes from discharges parallel to shoreline. Classes PL: Upstream intruding plumes.

FLOW CLASS S1

This flow configuration is profoundly affected by the linear ambient density stratification. The predominantly jet-like flow gets trapped at some terminal (equilibrium) level. The trapping is also affected by the reasonably strong ambient crossflow. Following the trapping zone, the discharge flow forms an internal layer that is further influenced by buoyant spreading and passive diffusion.

The following flow zones exist:

1) Weakly deflected jet in crossflow: The flow is initially dominated by the effluent momentum (jet-like) and is weakly deflected by the ambient current.

2) Strongly deflected jet in crossflow: The jet has become strongly deflected by the ambient current and is slowly rising toward the trapping level.

3) Terminal layer approach: The bent-over submerged jet/plume approaches the terminal level. Within a short distance the concentration distribution becomes relatively uniform across the plume width and thickness.

*** The zones listed above constitute the NEAR-FIELD REGION in which strong initial mixing takes place. ***

4) Buoyant spreading in internal layer: The discharge flow within the internal layer spreads laterally while it is being advected by the ambient current. The plume thickness may decrease during this phase. The mixing rate is relatively small. The plume may interact with a nearby bank or shoreline.

5) Passive ambient mixing: After some distance the background turbulence in the ambient shear flow becomes the dominating mixing mechanism. The passive plume is growing in depth and in width. The plume may interact with the upper layer boundary, channel bottom and/or banks.

*** Predictions will be terminated in zone 4 or 5 depending on the definitions of the REGULATORY MIXING ZONE or the REGION OF INTEREST. ***

Figure 5.1: Example of a Flow Class Description54 5.2 Quantitative Output: Numerical Flow Predictions

After execution of the detailed flow p rediction in program element H Y DROn, the

s y stem provides t w o t y pes of detailed numerical output on effluent plume trajector y

and mixing and

o n compliance w ith regulations. A concise

summar y is available on-screen in the final

s y stem element SU M and a detailed numerical

o u tput file is also generated for inspecting and plotting the plume's behavior after the anal y sis. 5.2.1 Summar y Output in SUM

T he self-explanator y summar y output

w hich can be displa y ed on-screen includes: (a) the date and time of the anal y sis section, (b) a complete ech o o f the input data, (c) the calculated flux, length scale and non-dimensional param e t e r values, (d) the flo w classification used for p redicting plume trajector y and mixing, (e) the

c oo r d inate s y stem used in the anal y sis, (f) a

summar y of the near-field region (NFR) conditions, (g) the far-field locations w here the plum e becomes essentiall y full y mixed (i.e. uniform concentration) in the hori z ontal and

v e rt i cal directions, (h) a summar y of the toxic dilution z one ( T DZ) conditions, and (I) a summary

o f the regulator y mixing z one (R M Z) conditions. Although the ra w data used to construct this

s u mmar y output is permanentl y stored in file 'fn'.C X C w ithin the output sub-directory COR M I X \SI M \C X n, a hard-cop y printout should be requested during the anal y sis sessio n because the ra w data file is unformatted and does not

c on t a in the explanator y text that is available d u ring program execution; 'fn' is the filename specified b y the user during input data entr y

.

T h e coordinate s y stem con v entions pertain to the origin location and axis direction. In COR M I X 1 anal y ses, the origin is located at the b o ttom of the receiving w ater just belo w the d i sc ha rge port center and thus, at a depth HD b e l o w t he w ater surface. In COR M I X 2 anal y ses, the origin is located at the bottom of the re c eiving

w ater, at the midpoint of the diffuser lin e an d thus,

a t a depth HD belo w the w ater surface. In COR M I X 3 anal y ses, the origin is located at the

w a t e r surface w here the discharge channel centerlin e and receiving w ater shoreline intersect. T he x-axis lies in th e hori z ontal plan e an d points do w nstream in the direction follo w ing the ambie n t f l o w ; the y -axis lies in the hori z ontal plane and points to the left as seen b y an observer looking d o w n s tream along the x-axis; and the z -axis p o i n ts verticall y up w ard. Note that w hen the

a m b i e nt current direction varies (e.g. due to

r e versing tidal f lows), the interpretation of simulatio n results becomes more involved since t h e x-axis and the y -axis w ill change depending on flo w direction.

In additio n to the numeri c al predi c tions of t h e plume si z e, location and chemical concentration, the summar y of the near-field

r eg i o n ( N F R ) conditions describes other relevant p l u m e f ea t u r e s s u c h a s b o t to m attachment, bank i n t e r a c t i on an d the degree of upstream intrusion. T his information is useful for both engineering d e s ign and for determining w hether important

r e s ou rce areas ma y be exposed to undesirable chemical concentrations.

In case of a toxic discharge, the s ummary t o xic dilution z one ( T DZ) conditions will indicate th e location along the plume w here the local concentration begins to fall belo w the specified C M C. COR M I Xautomaticall y checks compliance with the three geometric restrictions listed for mixing z ones associated w ith toxics discharges under alternative 3 (see Subsectio n 2.3.3) an d the

re s ults of these comparisons are displa y ed. The

user can evaluate the fourth alternative by referring to travel times given at the end of each simulation module in the related output files.

W he n regulator y mixing z one (R M Z) criteria have been specified during input data entr y , the geometric, dilution and concentration conditions at the edge of the specified or proposed R M Z are compared to these criteria and / o r t o t he applicable CCC concentration f ollo w ing the practices discussed in Subsection 2.2.4. The results of these comparisons are displa y ed.

5.2.2 Detailed Prediction Output File fn '.CXn

Th e file 'fn'.C X n stored w ithin sub-directory COR M I X \SI M contains the same kinds of i n f o r mation available in the summar y output plus t h e detailed numerical predictions on plume g e ometr y and mixing produced during the h y d raulic simulation. Data in that file forms the55 basis for further analysis, inspection, evaluation, 'fn".CXn output reflects that sequence and is a and plotting of the plume s hape and trajectory. arranged in output blocks for each module. The graphics package also uses the same data to plot on-screen, and print if desired, the plume Each simulation module has a "MODnxx" properties as explained in Section 5.2.3. label where "n" is 1, 2, or 3 corresponding to

During program execution, the user has number. The two general types of modules are several opportunities to display on-scr een or print continuous flow and control volume. out this file. It can also be printed at a later date by using the DOS PRINT command or any word processor. CORMIX will not erase any of the files with .CXn (or .CXC) extension that get stored in the CORMIX\SIM sub-directory. Consequently, periodic directory maintenance is recommended to remove old and superfluous files. This is best accomplished with a built-in file manager (see Main Menu) that deletes the specified files from the hard disk, but also erases their entry from the record keeping file CORMIX\SIM\CXn\summary.

The 'fn'.CXn file is a FORTRAN output file generated by the HYDROn prediction program. As is typical of many FORTRAN outputs, its display features are terse with tight format control and data items labeled in symbolic form only (e.g. "Q0" for discharge flow rate). Complete output file examples can be inspected in Appendices B, C and D.

All three CORMIXn subsystems produce a 'fn'.CXn output file with common appearance and features as descri bed in the following paragraphs.

a) Lead-in information: The output starts (and ends) with a " 111...111", "222...222", or "333...333" banner line to accentuate which subsystem has been used. The date and time of the analysis session and all important input data are the next items in the file. These are subsequently followed by the calculated length scale values, non-dimensional numbers of interest to the specialist, the flow class identification, and the coordinate system is displayed. b) Prediction results for each flow "module": As was mentioned previously in Subsection 3.6, the CORMIX prediction methodology utilizes a number of simulation modules that are executed jet or plume regions, the ratio of flux-average to sequentially and that correspond to the different minimum centerline dilution S /S = 1.7 and 1.3, flow processes and associated spatial regions for single-port round and multiport plane which occur within a given flow class. The discharges, respectively. CORMIXn, and "xx" is a two-digit identification

The continuous flow module type describes the continuous evolution of a flow region along a trajectory. Depending on the number of grid intervals specified by the user, information on plume geometry, flow, and mixing information along the plume trajectory may be available for a few or many water body locations.

Figure 5.2 provides examples of typical output from continuous flow modules. The annotations along the right margin illustrate important features of the output format. Figure 5.2a was taken from a CORMIX1 simulation output file and shows an example of a submerged jet region module (MOD110, equivalent to CORJET). The output contains labeling information on the module, and explanatory notes on profile definitions. It also gives a numerical list on the predictions, first repeating the final values from the preceding flow module and then one line for each user-specified grid interval. This information gives the x-y-z position of the jet/plume centerline, the dilution (S) and concentration (C) at the centerline, and the jet width (B).

Dilution (S) is defined as the ratio of the initial concentration (at the discharge port) to the concentration at a given location, irrespective ofany decay or growth effects if specified for a nonconservative pollutant. However, concentration(C) will include any first-order effects for nonconservative pollutants. Dilution (S) given by CORMIX for submerged jet or plume regions is the minimum centerline dilution for the jet/plume. The control volume and buoyant spreading modules give bulk dilutions, which are equivalent to flux-averaged dilutions for these regions. If a flux-averaged dilution S is desired for submerged f

f56 ----------------------------------------------------------------------------- BEGIN CORJET (MOD110): JET/PLUME NEAR-FIELD MIXING REGION Jet/plume transition motion in weak crossflow. Zone of flow establishment: THETAE= 0.00 SIGMAE= 277.06 LE = 3.39 XE = 0.21 YE = -3.38 ZE = 1.00 Profile definitions: B = Gaussian 1/e (37%) half-width, normal to trajectory S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any) X Y Z S C B 0.00 0.00 1.00 1.0 0.100E+03 0.76 0.21 -3.38 1.00 1.0 0.100E+03 0.76 0.90 -7.41 4.11 1.8 0.562E+02 1.13 1.55 -9.36 9.07 3.3 0.300E+02 1.59 2.23 -10.55 14.27 5.4 0.186E+02 2.10 2.95 -11.39 19.56 7.9 0.127E+02 2.63 3.72 -12.02 24.85 10.8 0.928E+01 3.16 Cumulative travel time = 18. sec END OF CORJET (MOD110): JET/PLUME NEAR-FIELD MIXING REGION

-----------------------------------------------------------------------------

a) Submerged buoyant jet module

----------------------------------------------------------------------------- BEGIN MOD341: BUOYANT AMBIENT SPREADING Profile definitions: BV = top-hat thickness, measured vertically BH = top-hat half-width, measured horizontally from bank/shoreline S = hydrodynamic average (bulk) dilution C = average (bulk) concentration (includes reaction effects, if any) Plume Stage 1 (not bank attached): X Y Z S C BV BH 1.93 -.82 0.00 8.4 .884E+00 .03 .58 2.07 -.82 0.00 8.5 .869E+00 .03 .62 2.20 -.82 0.00 8.6 .856E+00 .03 .65 ** WATER QUALITY STANDARD OR CCC HAS BEEN FOUND ** The pollutant concentration in the plume falls below water quality standard or CCC value of .850E+00 in the current prediction interval. This is the spatial extent of concentrations exceeding the water quality standard or CCC value. 2.34 -.82 0.00 8.8 .844E+00 .03 .68 2.48 -.82 0.00 8.9 .833E+00 .03 .71 2.62 -.82 0.00 9.0 .822E+00 .03 .74 2.76 -.82 0.00 9.1 .811E+00 .03 .77 2.89 -.82 0.00 9.2 .801E+00 .03 .80 2.96 -.82 0.00 9.3 .796E+00 .03 .82 Cumulative travel time = 95. sec

------------------------------------------------------------------- ---------- Plume is ATTACHED to LEFT bank/shore. Plume width is now determined from LEFT bank/shore. Plume Stage 2 (bank attached): X Y Z S C BV BH 2.96 .00 0.00 9.3 .796E+00 .03 .82 16.05 .00 0.00 31.3 .237E+00 .03 2.59 29.13 .00 0.00 96.8 .764E-01 .06 3.77 42.22 .00 0.00 220.7 .335E-01 .10 4.76 55.31 .00 0.00 411.4 .180E-01 .16 5.64 68.39 .00 0.00 675.3 .110E-01 .23 6.45 81.48 .00 0.00 1017.8 .727E-02 .31 7.20 94.56 .00 0.00 1443.5 .513E-02 .40 7.91 101.11 .00 0.00 1688.9 .438E-02 .45 8.26 Cumulative travel time = 3367. sec END OF MOD341: BUOYANT AMBIENT SPR EADING

-----------------------------------------------------------------------------

b) Far-field flow module (example of buoyant spreading with bank contact)

Figure 5.2: Examples of continuous flow modules within CORMIX57 The cumulative travel time (T) is given at the end of each simulation module. The travel time can be used to assess the applicability of the c) Numerous other supplementary messages steady-state predictions given by CORMIX to time on plume behavior (e.g. bottom attachment, bank scales appropriate for the particular application. contact, etc.) and on possible model restrictions

Another example of a continuous flow restricted river) are contained in the output as module output is shown in Figure 5.2b. It was warranted; Figures 5.2 and 5.3 provide but a few abstracted from a CORMIX simulation output file examples of these user aids. and shows predictions for the far-field process of buoyant ambient spreading (Figure 2.6). Although it is terse, the output file values and commentary generally provide a complete picture of flow conditions. In this example output (Figure 5.2b), evidence of this completeness includes: (a) the prediction output is separated in two stages corresponding to before and after bank interaction, respectively; due to the typical oblong cross-section of the plume in this stage, width dimensions for the vertical and lateral extent are given and defined; the coordinates for the upper and lower boundaries of the plume are listed as a convenience for plotting; and the system searches for criteria that apply to mixing zone regulations and when a criterion is satisfied, a remark gets inserted in the output list at the appropriate spatial position. (Note: The l ength dimensions in Figure 5.2b are small as they relate to a laboratory simulation.)

Some mixing flow processes are so complicated that no mechanistically-based mathematical description of them is presently available in state-of-the-art science. Those processes are best analyzed with control volume modules as shown in Figure 5.3. inspection and evaluation of results.

In the control volume modeling approach, the prediction after the file has been stored, outflow values for a region are computed as a by entering the Post-Processor option in function of the inflow values and are based on the Iteration Menu. conservation principles. (1c) It can be accessed on earlier existing

An output example for control volumes Processor option in the Main Menu. modules is illustrated in Figure 5.3. It is taken from a CORMIX1 simulation output file and gives (2) Use outside CORMIX: predictions for a flow case corresponding to an The graphics system can be invoked unstable near-field (Figure 2.2c). Note that a directly by typing: separate listing of inflow variables and outflow variables is given with appropriate explanations. cmxgr aph (or simply: cg) filename The tabular listing of plume shape is based on an where filename (including path and interpolation routine using a generic plume s hape extension) is any prediction file generated for these upstream intruding motions, rather than by CORMIX or by CORJET. a detailed computation.

(e.g. ambient dilution limitations in a flow5.3 Graphical Output: Display and Plotting of Plume Features Using CMXGRAPH

5.3.1 Access to CMXGRAPH

CMXGRAPH is a specially developed graphics package, written in C++, for the display and plotting of CORMIX ( and also CORJET, see Section 6.2) predicted effluent plumes. It uses the prediction files 'fn'.CXn that are stored in the directory CORMIX\SIM, and plots plume features based on the numerical and narrative information contained in these files.

The graphics system can be accessed in different ways:

(1) Use within CORMIX: Different access modes exist here.

(1a) The user can display the plume graphics immediately after the actual prediction and before the file information is stored . This is useful for an initial

(1b) It can be accessed at an end of the

files by directly choosing the Post-58 ----------------------------------------------------------------------------- BEGIN MOD132: LAYER BOUNDARY IMPINGEMENT/UPSTREAM SPREADING

Vertical angle of layer/boundary impingement = 79.65 deg Horizontal angle of layer/boundary impingement = 324.93 deg

UPSTREAM INTRUSION PROPERTIES: Upstream intrusion length = 328.95 m X-position of upstream stagnation point = -325.23 m Thickness in intrusion region = 0.55 m Half-width at downstream end = 470.97 m Thickness at downstream end = 0.70 m

In this case, the upstream INTRUSION IS VERY LARGE, exceeding 10 times the local water depth.

This may be caused by a very small ambient velocity, perhaps in combination with large discharge buoyancy.

Control volume inflow:

X Y Z S C B 3.72 -12.02 24.85 10.8 0.928E+01 3.16

Profile definitions:

BV = top-hat thickness, measured vertically BH = top-hat half-width, measured horizontally in Y-direction ZU = upper plume boundary (Z-coordinate) ZL = lower plume boundary (Z-coordinate) S = hydrodynamic average (bulk) dilution C = average (bulk) concentration (includes reaction effects, if any)

X Y Z S C BV BH ZU ZL -325.23 -12.02 28.00 9999.9 0.000E+00 0.00 0.00 28.00 28.00 -313.94 -12.02 28.00 46.5 0.215E+01 0.13 66.61 28.00 27.87 -258.63 -12.02 28.00 19.3 0.519E+01 0.31 161.78 28.00 27.69 -203.31 -12.02 28.00 14.5 0.688E+01 0.40 218.89 28.00 27.60 -148.00 -12.02 28.00 12.5 0.802E+01 0.47 263.91 28.00 27.53 -92.68 -12.02 28.00 11.4 0.878E+01 0.52 302.30 28.00 27.48 -37.37 -12.02 28.00 10.9 0.919E+01 0.54 336.34 28.00 27.46 17.95 -12.02 28.00 11.0 0.913E+01 0.55 367.24 28.00 27.45 73.26 -12.02 28.00 14.4 0.694E+01 0.59 395.73 28.00 27.41 128.58 -12.02 28.00 19.1 0.522E+01 0.65 422.30 28.00 27.35 183.89 -12.02 28.00 22.0 0.455E+01 0.68 447.30 28.00 27.32 239.21 -12.02 28.00 23.2 0.431E+01 0.70 470.97 28.00 27.30 Cumulative travel time = 3037. sec

END OF MOD132: LAYER BOUNDARY IMPINGEMENT/UPSTREAM SPREADING

-----------------------------------------------------------------------------

Figure 5.3: Example of control volume flow module59 As mentioned, numerous flow features (as evidenced by the different flow classes) can 5.3.2 Use of CMXGRAPH occur. It is difficult to develop a robust graphicspackage that operates safely for all of these The graphics system has a selfpossibilities. The CMXG RAPH system has been explanatory screen interface as shown in Figure widely tested, but occasional crashes can occur for rare flow module combinations and then only for certain plot types. Should a crash occur and the direct access mode (1a), listed above, has been used then the current file information will be lost. In those cases, it is safer to first save the current session file data and then exercise the graphics system. 5.4. The menu is controlled by the keyboard alone by typing the letters that appear in capital on the menu buttons, or by user the four cursor keys when in zoom mode.

The GRAPHICS MENU COMMANDS are as follows:

H elp an advice section is available listing the same information as given here

Q uit exits the graphics system

There exist FIVE PLOT TYPES:

P lan generates a plan view of plume (x-y), as seen from above (entry option)

S ide generates a side view of plume (x-z), as s een by an observer looking from the bank/shore

T raj generates a side view along trajectory of plume. The view is stretched out along the actually curving centerline trajectory.

c- X generates a plot of concentration on the plume centerline plotted against downstream distance x

c- D generates a plot of concentration on the plume centerline plotted against distance along the plume trajectory

The user can CONTROL the plume VIEW:

N ear displays the near-field region only ; useful for close-up details (entry option)

F ull displays the complete near- and far-field regions (i.e. the entire prediction results)

SHOW/HIDE FEATURES can be exercised to display additional information:

L abels puts identifier labels (site/case information) on top of plot (entry option)

W qual displays information on r egulatory mixing regulations (TDZ, RMZ, ...) on the plot; this is60 displayed by dotted lines where particular regulations are encountered.

M odule shows boundaries of prediction modules

ZOOM/SCALE CONTROL allows control of plot details:

Z oom allows the user to enlarge any RECTANGULAR SECTION of the current plot; this is accomplished by: -- Use CURSOR Control keys to move cursor (up,down,left,right)

-- Cursor SPEED can be modified by typing any number: 1(slowest),2,.. to 0(fastest) -- Press RETURN when first corner of desired rectangle has been reached -- Move cursor to find opposite corner and press RETURN to fix opposite corner

s K ale allows the user to FIX SCALE distortion of current plot. The current scale is displayed in a window on the menu bottom (see Figure 5.4). -- Type in desired distortion at the prompt: All subsequent versions of the plot (including zooms will be fixed at this scale distortion. -- Use the sKale button again, to release the scale distortion.

B kup back-up to earlier zoomed/scaled versions of current plot

Esc exit from zoom/scale mode (also Quit or repeated Bkup can be used to exit)

Several PRINT OPTIONS are available:

pf I le writes the current plot to a POSTSCRIPT FILE for later printing. The file can be edited and/or printed later using any compatible software (including public domain software, such as Ghostscript).

-- Each print file is stored as \" filename .Pvn\" where:

filename = CORMIX or CORJET assigned filename, Pvn = file extension indicating a Postscript file, v = P, S, T, X or D, for one of the five view types, n = 0 to 9, increasing file number.

-- If the total file number for a particular view type exceeds the maximum of ten (10), the first file in the series will be erased and replaced by the new file.

ps C rn allows a PRINT SCREEN action of the current plot

-- The plot is first recreated without the menu interface and plot border.

-- Then use the Shift-PrintScreen buttons, to print the plot on-line. Important: The PRINTER must have been initialized for GRAPHICS MODE with the DOS command: \"gr aphics [type] /r\" where: [type] = type of printer (e.g.: color4, laserjetii).

### 61 Figure 5.4 C M XGRAPH inter f ace w ith menu options including example plot

### c ( n ) c c



### e ( n b ) 2

62 The case study materials in the Appendices show some of the possibilities that can be exercised in the graphics display the plume features described in the fn .CXn output files. As shown above, the plume is characterized by its centerline trajectory, dilution, and width values. For understanding added detail in the plume cross-section, it is important to keep in mind the different concentration distributions and meanings of "plume width". These are explained in the supplemental statements at the beginning of each flow module (see Figures 5.2 and 5.3). Also, Figure 5.5 may be useful for further illustration. It gives the cross-sectional distribution of concentration for many of the commonly occurring plume cross-sections in the various regions predicted by the CORMIXn subsystems.

In some instances, users may desire to plot concentration isolines for the predicted plume shapes. The information contained in the HYDROn output file for each module and the definitions shown in Figure 5.5 are sufficient to construct such plots. In particular, in submerged plume or passive mixing regions having a Gaussian distribution, the following formula can be used

where c(n) is the lateral concentration, n is the coordinate position measured tranversely away from the centerline 

### , c is the centerline c concentration, e is the natural logarithm base, and b is the local plume half-width. However, this equation can not be used to plot concentration isolines in the control volume or buoyant spreading regions because they are defi ned with a top-hat or uniform concentration profile and not a Gaussian distribution.

By and large, all CORMIXn predictions are continuous from m odule to module satisfying the conservation of mass, momentum and energy principles. Occasionally, some mismatches in plume width can occur as a consequence of enforcing these principles. Most of these will be barely noticeable with the usual plotting resolution and they can usually be safely i gnored. Some of the mismatches or discontinuities can be kept to a minimum by specifying a large number for the grid intervals (see Section 4.9) to increase the resolution of the CORMIX prediction. This is especially useful for the final simulations on a particular design case.

In addition, when bottom attachment or bank interaction occurs, the plume trajectory is assumed to (and simulation predictions do) shift suddenly to the boundary. In actuality, that shift would be much more gradual and this should be considered when interpreting the results of the CMXGRAPH plots or, alternatively, w hen plotting plume features by hand.

### 63 Figure 5.5: Cross-sectional distributions of CORMIX predicted jet/plume sections6465 

## VI Post-Processor Models CORJET and FFLOCATR: Input and Output Features

The CORMIX system contains three post- recent CORMIX system enhancements. CORJET processor options which be accessed directly is a type of a jet integral model whose original from within the system or independently outside of development in a two-dimensional framework and CORMIX. In either case, the post-processor for a round jet only was first r eported in the peeroptions provide additional enhancements to reviewed literature by Jirka and Fong (25). CORMIX in terms of plume display, and more Detailed verification studies with various detailed computation of near- and far-field plume experimental data sources have been reported features. (8,26).

The first of the options, the graphics In jet integral models the hydrodynamic package CMXGRAPH, has already been equations governing the conservation of mass described in Section 5.3. The second option is and momentum, and of other quantities as CORJET, the Cornell Buoyant Jet Integral Model, pollutant mass, density deficit, temperature and/or for the detailed analysis of the near-field behavior salinity, are solved step-wise along the general of buoyant jets. FFLOCATR, the Far-Field curved jet trajectory. The solution yields values of Plume Locator, for the far-field delineation of the trajectory position itself and of the centerline discharge plumes in non-uniform river or estuary concentrations of these quantities, while the environments is the third option. The latter two actual cross-sectional distribution is fixed a priori are described in this chapter. (mostly as a Gaussian distribution) in these

6.1 CORJET: The Cornell Buoyant Jet Integral Model 6.1.1 General Features

CORJET is a Fortran model that solves the three-dimensional jet integral equations for submerged buoyant jets --either a single round jet or interacting multiple jets in a multiport diffuser -- in a highly arbitrary ambient environment. The ambient/discharge conditions include an arbitrary discharge direction, positive, neutral or negative discharge buoyancy, anarbitrary stable density distribution, and a nonuniform ambient velocity distribution with magnitude and direction as a function of vertical position.

Figure 6.1 displays these general characteristics for the case of a single port. In case of the multiport diffuser all the discharge port/nozzles point in the same direction (unidirectional or staged design) and the diffuser line can have an arbitrary alignment angle relative to the ambient current (for definitions see Section 4.5.1).

The detailed theoretical basis for CORJET can be found in the documentation report (8) on models. Literally several dozen such model developments have been reported in the literature over the last thirty years or so of research on these mixing phenomena. Most of these developments differ (I) in the degree of simplifying assumptions on the ambient/discharge characteristics (e.g. two-dimensional trajectories or uniform ambient conditions only), and (ii) in the type of closure that is made to specify the turbulent growth and entrainment behavior in these jets under a variety of forcing conditions. Thus, some of these models can be demonstrated to be unduly limited for practical applications, and others to be clearly invalid in certain limiting regimes of plume behavior.

Whenever a jet integral model is reasonably general in its formulation and has been validated through experimental data comparison under a number of conditions it canbe considered a useful prediction tool for nearfield plume analysis. For practical purposes, all the models that meet the above conditions, in fact, differ little in their prediction results. The deviation among model results is usually less than the scatter in experimental data that is used for their verification. This holds true also for CORJET as well as another jet integral model,

### 66 Figure 6.1: General three-dimensional trajectory of submerged buoyant jet in ambient flow with arbitrary density and velocity distribution: Case of a single round jet

(27), that has current USEPA support and distribution.

Both CORJET and PLUMES, although they differ in their internal formulation and closure assumptions, have a wide generality in discharge/ambient conditions and a reasonable verification base for a variety of conditions. They can deal with three-dimensional trajectories, with positive, neutral or negative discharge buoyancy, with conditions of reversible buoyancy (so-called nascent conditions in freshwater systems due to the density maximum at 4 o 

### C, requiring use of the full non-linear equation of state), with first-order pollutant decay, with variable stable ambient density, and with sheared non-uniform ambient currents, and with the merging of multiple port diffuser plumes. Three specialized features that the PLUMES model cannot deal with are a variable current direction at different levels, arbitrary diffuser alignments (with the extreme of a fully parallel alignment, γ = 0 o 

### in Figure 4.6), and applications to atmospheric plumes (using the concept of potential temperature and density).

Jet integral models, such as CORJET and67 PLUMES, appear as useful and efficient tools for by entering the Post-Processor option in the rapid analysis of the near-field mixing of the Iteration Menu. aqueous discharges. They r equire fairly little (1b) It can be accessed on earlierinput data and are numerically efficient. However, existing files by directly choosing the Posttheir inherent limitations must be kept in mind. Processor option in the Main Menu.

All jet integral models , including CORJET, assume an infinite receiving water body , without any boundary effects due to limiting dimensions vertically (surface, bottom, or pycnocline) or laterally (banks or shore). Thus, they do not deal with such hydrodynamic effects as jet attachment and near-field instabilities that are so prevalent in many aqueous discharge plumes as emphasized in Section 2.1.1. Furthermore, they are near-field models only and do not give predictions on what happens to the entire mixing zone that may often cover larger distances (see Section 2.2.5).

In summary, jet integral models if used alone and by an inexperienced analyst are not a safe methodology for mixing zone analysis

. They become safe only when used in conjunction with a more comprehensive analysis using the full CORMIX system. Therefore, in case of engineering design applications, CORJET should be employed after prior use of the expert system CORMIX has indicated that the buoyant jet will not experience any instabilities due to shallow water or due to attachment to boundaries

. In fact, the CORMIX system has built in several safeguards and warning statements to the user as explained below. When used in that context CORJET becomes a highly useful addition to the CORMIX system that can provide considerable additional detail and sensitivity analysis in the immediate near-field of the discharge plume.

6.1.2 Access to CORJET

CORJET, like the other post-processor options such as the graphics system (Section 5.3.1), can be accessed in different ways: (1) Use within CORMIX:

(1a) It can be accessed at an end of the prediction after the file has been stored, In either case, once the CORJET option is chosen the user must first specify whether a CORMIX1 or 2 simulation should be analyzed for the near-field with CORJET. Then the CORMIX1 or 2 filename in the CORMIX\SIM directory must be specified. CORJET will run automatically using the input data of the given CORMIX data file.

(2) Use outside CORMIX: CORJET can be invoked directly by typing: corjet (or simply: cj) filename where filename (including path and extension) is any specially prepared input data file (see following section). Alternatively if one types: corjet (or simply: cj) the model will prompt the user for the input data filename.

6.1.3 CORJET Input Data File

This section for data preparation applies only if CORJET is run independently from the CORMIX system as discussed above. The checklist given on the following page is useful for data assembly prior to input data entry.

In this case, the Fortran model CORJET reads input data file with filenamethat is userspecified with arbitrary name, extension and directory. For user convenience it is recommended that all such files be kept in the special directory CORMIX\POST\CJ.

The input data file is a Fortran-readable file that is read in open format, that is all perti nent data values are arranged on a line and separated by one or more open spaces. The file consists of five data blocks, each of which must be lead in by two dummy lines that are not read. Table 6.1 gives an example of a data file in which the dummy lines are indicated by the # sign.68 Table 6.1 Example of an input data file for CORJET

#CORJET INPUT FILE #Title line (50 characters max.): Case2: SINGLE PORT, STRATIFIED, VARIABLE CURRENT #Fluid (1=water,2=air), Density option (1=calculate,2=specify directly): #Fluid (1⁄2): Density option (1⁄2): Ambient levels (1-10): 1 1 3 #Ambient conditions (if d.o.=1, fill in TA+SA; if 2, fill in RHOA): #Level ZA TA SA RHOA UA TAUA 1 0. 12. 30. 0.5 0. 2 5. 15. 29.5 0.8 0. 3 15. 20. 28. 1.2 0. #Discharge conditions (T0+S0, or RHO0 as above; if NOPEN=1: set LD=0,ALIGN=0): #NOPEN D0 H0 U0 THETA0 SIGMA0 C0 KD T0 S0 RHO0 LD ALIGN 1 0.5 0. 3.0 45. 45. 100. 0. 30. 0. 0. 0. #Program control: #ZMAX ZMIN DISMAX NPRINT 30. 0. 200. 10

The required input data values (all in SI units) are discussed in the following. The definition of these values is entirely consistent with those for CORMIX (in particular, see Section 4.4 and 4.5 for discharge conditions).

Block 1: Identifier LABEL: Any descriptive label/text (should not exc eed 50 characters, so that it does not get truncated on the graphics plots)

Block 2: Fluid and density specification IFLUID: 1 (water) or 2 (air, for atmospheric applications) IDENOP: 1: in case of water: Density will be calculated from specified temperature and/or salinity In case of air: Potential density will be calculated from potential temperature assuming dry adiabatic conditions 2: Density values will be specified directly LEVAMB: Number of levels for which ambient conditions are given (1 to 10)

Block 3: Ambient Conditions (specify LEVAMB lines) LEV: Level number (increasing from 1 to LEVAMB) ZA: Specify vertical level (z-coordinate) (m) TA : if IFLUID=1(water): Temperature at ZA (degC) (omit if IDENOP=2) if IFLUID=2(air): Potential temperature at ZA (degC) (omit if IDENOP=2) SALA: Salinity at ZA (ppt) (omit if IDENOP=2 or if IFLUID=2) RHOA: if IFLUID=1: Density at ZA (kg/m ) (omit if IDENOP=1) 3 if IFLUID=2: Potential density at ZA (kg/m ) (omit if IDENOP=1) 3 UA: Ambient velocity (speed) at ZA (m/s) TAUA: Angle of ambient velocity vector measured CCW from x-axis (deg) (set = 0. unless velocity distribution in vertical is skewed, i.e. spiral-type)

Block 4: Discharge Conditions NOPEN: 1: if SINGLE PORT DISCHARGE (i.e. 1 opening) >= 3: number of openings (ports) for MULTIPORT DIFFUSER D0: Port diameter (m) (should include contraction effects if any) H0: Port center height above x-y plane (m) U0: Jet exit velocity (m/s) THETA0: Vertical angle of discharge (deg)70 SIGMA0: Horizontal angle of discharge axis measured CCW from x-axis (deg) Examples: 0. = co-flow, 90. or 270. = cross-flow, 180. = counterflow C0: Discharge concentration (any units that need not be specified) KD: Coefficient of substance decay [negative value if growth] (/s) T0: Discharge temperature (degC) (omit if IDENOP=2) S0: Discharge salinity (ppt) (omit if IDENOP=2 OR IF IFLUID=2) RHO0: Discharge density (kg/m ) (omit if IDENOP=1) 3 LD: Diffuser length (m) (set = 0. [non-blank] if NOPEN=1) ALIGN: Diffuser alignment angle (deg) measured CCW from x-axis (set = 0. if NOPEN=1) Examples: 0. = parallel diffuser, 90. = perpendicular diffuser

Block 4: Program Control ZMAX: Maximum vertical coordinate of interest (m) ZMIN: Minimum vertical coordinate of interest (m) ZMAX and ZMIN are cutoffs for + and - buoyancy, respectively! DISMAX: Maximum distance of interest along trajectory (m) NPRINT: Print intervals (any positive number less than 100; recommended value 5 to 10; does not affect accuracy of computation!)

Note on density specification: It is at the level of origin. important to note the mutual exclusivity for the indirect or direct density specification as listed The CORMIX system contains upon its above. Omit the values (i.e. leave blank spaces) depending on the value of the I DENOP parameter. This can be seen in the preceding example data file. Up to 10 ambient levels can be specified for density and velocity distribution. This is sufficient to replicate complicated observed ambient profiles. CORJET performs internal consistency checks to test whether the specified density distribution is statically stable. R egardless of the access m ode (within or

The coordinate system in CORJET can, in principle be taken as consistent with the CORMIX1 and 2 conventions (Section 5.2.1), i.e. the origin at the bottom of the receiving water (a) CORJET Output File: body. (In fact, this convention is exercised whenever CORJET is run from within CORMIX.) (a.1) Use within CORMIX: However, since CORJET does not recognize the dynamic effect of the presence of the actual The output file gets stored as bottom boundary it is often convenient to set the CORMIX\POST\CJ\ fn .CJX where fn is the origin at the center of the discharge port. In that CORMIX1 or 2 filename that has been specifiedcase the port height H0 must be entered as 0.0. during the data entry. This file can be viewed onx points horizontally in the downstream direction, screen or printed within CORMIX. y laterally across in the horizontal plane, and z vertically upward. In the rare case when the A typical CORJET output file generated in ambient velocity distribution is skewed in the this access mode is shown in Table 6.2 below vertical, the definition of the x direction is best corresponding to the input example presented made by the direction of the ambient velocity at the level of origin (then TAUA is 0.0 at that level!), but any other convention is possible, too, and can be implemented by the choice of the TAUA value installation several CORJET case studies (see also Appendix E ) that are installed as CORMIX\POST\CJ\case*.inp. It is recommended to copy one or more of these files and use the copy for constructing any future input data file.

6.1.4 CORJET Output Features

outside of CORMIX) CORJET has two output mechanisms, a numerical output file and a graphical display by means of CMXGRAPH.

above. The header information starts with the banner ‘JJJ’ and then echoes all the pertinent data that had been supplied to CORMIX and had been picked up for the CORJET simulation. The71 underlying CORMIX1 or 2 flow class is listed. If one of the unstable or bottom-attaching flow classes is encountered in this access m ode, then CORJET will not provide any predictions since a pure jet integral model would not be applicable

. The tabular listing (see Table 6.2 ) gives the plume values along the trajectory. CORJET will cut off at a vertical level ZMAX that is equal to the water depth at discharge or ZMIN = 0.0 (for negatively buoyant cases) equal to the water body bottom. In neither case does it compute the actual boundary approach or impingement processes (as does the more complete CORMIX model in which some CORJET elements are, in fact, integrated, starting with Version 3.0). The interpretation of data values in this tabular listing is consistent with that for CORMIX1 or 2 (see Section 5.2.2).

Table 6.2 Example of CORJET output file when accessed within CORMIX

CORJET PREDICTION FILE: JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ CORJET: CORNELL BUOYANT JET INTEGRAL MODEL Version 4.0, March 1995

---------------------------------------------------------------------------- FILE NAME: cormix\post\cj\SAMPLE1.CJX Label/identifier: A-PLANT^SUMMER^STRATIFICATION Time of CORJET run: 4/12/96--18:40:19 NEAR-FIELD DATA values for earlier CORMIX1 prediction (metric): Site name/label: DEEP^RESERVOIR Design case: A-PLANT^SUMMER^STRATIFICATION FILE NAME: cormix\sim\SAMPLE1 .CX1 Time of CORMIX run: 06/24/95--22:29:54 HD = 30.50 UA = .01 CUNITS= PPM STRCND= C density stratified environment RHOAS = 996.21 RHOAB = 999.61 HINT = 15.50 DRHOJ = 2.181 FLOCLS= S3 Corresponding CORJET ambient conditions: LEV ZA RHOA UA TAUA 1 .00 999.61 .01 .00 2 14.75 998.39 .01 .00 3 16.25 996.21 .01 .00 4 30.50 996.21 .01 .00 Pycnocline thickness has been set to 1/10 of upper layer thickness. Discharge conditions (metric): SINGLE PORT D0 H0 U0 THETA0 SIGMA0 C0 KD RHO0 .254 .60 3.02 10.00 90.00 .35E+04 .00E+00 998.21 Program control: ZMAX ZMIN DISMAX NPRINT 30.50 .00 1525.00 10 Flux variables (based on ambient at discharge level): Q0 = .153E+00 M0 = .462E+00 J0 = .203E-02 GP0 = .133E-01 Length scales (m) and parameters: LQ = .23 LM = 12.44 Lm = 45.31 Lb = 601.53 Lmp = 4.88 Lbp = 3.06 FR0 = 52.01 R = 201.31

---------------------------------------------------------------------------- CORJET PREDICTION: Stepsize = .2251 Printout every 10 steps Single jet/plume: X Y Z Sc Cc B | DIST Save Gpc Flc .00 .00 .60 1.0 .350E+04 .13| .00 1.0 .13E-01 52.01 .01 1.23 .82 1.0 .350E+04 .13| 1.25 1.4 .16E-01 95.03 .04 3.45 1.22 2.5 .142E+04 .37| 3.50 4.2 .50E-02 33.42 .11 5.65 1.65 4.1 .852E+03 .62| 5.75 7.0 .25E-02 21.98 .22 7.85 2.13 5.8 .607E+03 .87| 8.00 9.8 .12E-02 19.01 .35 10.04 2.65 7.4 .471E+03 1.12| 10.25 12.6 .32E-03 25.46 .44 11.13 2.92 8.3 .423E+03 1.25| 11.38 14.0 -.59E-04 50.81 Level of buoyancy reversal in stratified ambient. .53 12.22 3.19 9.1 .384E+03 1.37| 12.50 15.4 -.40E-03 16.80 .74 14.40 3.68 10.8 .325E+03 1.63| 14.76 18.2 -.97E-03 8.35 .99 16.61 4.06 12.4 .282E+03 1.88| 17.01 21.0 -.13E-02 5.70 1.28 18.83 4.20 14.1 .248E+03 2.14| 19.26 23.8 -.13E-02 4.61 1.31 19.05 4.20 14.3 .245E+03 2.17| 19.48 24.1 -.13E-02 4.56 Maximum jet height has been reached. 1.62 21.05 4.05 15.9 .220E+03 2.40| 21.51 26.8 -.99E-03 4.54 1.99 23.23 3.63 17.8 .196E+03 2.66| 23.76 30.0 -.34E-03 6.68 2.19 24.31 3.37 18.8 .187E+03 2.80| 24.89 31.6 .27E-04 22.15 Terminal level in stratified ambient has been reached. PROGRAM STOPS!

---------------------------------------------------------------------------- END OF CORJET PREDICTION: Total number of integration steps = 106 JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ72 The main usefulness of CORJET when 6.1.2(2) ). This file can be viewed on-screen or run in this mode lies in the short and separate printed using any text processor. display of the near-field buoyant jet only. In some cases, the pertinent regulatory constraints may be The CORJET output file corres ponding to limited to that region. the input data file of Table 6.1 is listed in Table

(a.2) Use outside of CORMIX: data and then lists the calculated length scale and The output file gets stored as non-dimensional numbers controlling the mixing filename .OUT in the same directory for which the process. user had specified the input file (see Section 6.3. The lead-in data provide an echo of the input

Table 6.3 Example of CORJET output file

CORJET PREDICTION FILE: JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ CORJET: CORNELL BUOYANT JET INTEGRAL MODEL Version 4.0, March 1995

---------------------------------------------------------------------------- FILE NAME: post\cj\case2.OUT Label/identifier: Case2: SINGLE PORT, STRATIFIED, VARIABLE CURRENT Time of CORJET run: 4/10/96--19:28: 6

Ambient conditions: No. of levels: 3 Fluid: Water Density option: 1 LEV ZA TA SA RHOA UA TAUA 1 .00 12.00 30.00 1022.71 .50 .00 2 5.00 15.00 29.50 1021.74 .80 .00 3 15.00 20.00 28.00 1019.43 1.20 .00 Discharge conditions (metric): SINGLE PORT D0 H0 U0 THETA0 SIGMA0 C0 KD T0 S0 RHO0 .500 .00 3.00 45.00 45.00 .10E+03 .00E+0 30.0 .0 995.65 Program control: ZMAX ZMIN DISMAX NPRINT 30.00 .00 200.00 10 Flux variables (based on ambient at discharge level): Q0 = .589E+00 M0 = .177E+01 J0 = .153E+00 GP0 = .259E+00 QT0 = .106E+02 QS0 = -.177E+02 Length scales (m) and parameters: LQ = .44 LM = 3.92 Lm = 2.66 Lb = 1.22 Lmp = 5.61 Lbp = 6.71 FR0 = 8.33 R = 6.00 Zone of flow establishment (m): LE = 1.30 XE = .75 YE = .62 ZE = .86 THETAE= 38.34 SIGMAE= 34.00 GAMMAE= 49.43

---------------------------------------------------------------------------- CORJET PREDICTION: Stepsize = .2659 Printout every 10 steps Single jet/plume: X Y Z Sc Cc B | DIST Save Gpc dTc dSALc .00 .00 .00 1.0 .100E+03 .25| .00 1.0 .26E+00 18.0-30.0 .75 .62 .86 1.0 .100E+03 .25| 1.30 1.4 .27E+00 20.8-34.7 2.81 1.50 2.27 3.0 .334E+02 .64| 3.96 4.6 .83E-01 5.2 -9.9 5.22 1.96 3.28 5.7 .176E+02 .94| 6.62 8.3 .42E-01 2.1 -5.1 7.74 2.22 4.07 8.4 .118E+02 1.16| 9.27 12.1 .26E-01 .8 -3.3 10.31 2.40 4.74 11.2 .890E+01 1.34| 11.93 15.8 .18E-01 .1 -2.4 12.90 2.52 5.32 14.0 .716E+01 1.49| 14.59 19.5 .13E-01 -.3 -1.9 15.51 2.61 5.84 16.6 .601E+01 1.62| 17.25 23.2 .96E-02 -.6 -1.5 18.12 2.68 6.31 19.2 .520E+01 1.74| 19.91 26.7 .70E-02 -.8 -1.2 20.75 2.73 6.74 21.7 .460E+01 1.84| 22.57 30.0 .50E-02 -1.0 -1.0 23.38 2.78 7.13 24.1 .414E+01 1.93| 25.23 33.3 .34E-02 -1.1 -.8 26.01 2.82 7.48 26.4 .379E+01 2.01| 27.89 36.3 .21E-02 -1.3 -.6 28.65 2.85 7.80 28.5 .351E+01 2.08| 30.54 39.1 .10E-02 -1.4 -.5 31.29 2.88 8.09 30.4 .329E+01 2.14| 33.20 41.6 .15E-03 -1.5 -.4 31.82 2.89 8.14 30.8 .325E+01 2.15| 33.73 42.1 -.13E-04 -1.5 -.4 Terminal level in stratified ambient has been reached. PROGRAM STOPS!

---------------------------------------------------------------------------- END OF CORJET PREDICTION: Total number of integration steps = 123 JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ73 The actual tabular listing of the numerical accomplished. output is divided in two halves by a vertical line. The left half lists data exactly in the same fashion as a CORMIX1 or 2 prediction file (see Section 5.2.2). The right half gives additional detailed information on the following variables:

DIST: distance (m) along the jet trajectory Save: average (bulk) dilution, defi ned on the basis of total volume flux within the jet relative to the initial volume flux (discharge) Gpc: centerline buoyant acceleration (m/s ) 2 dTc: centerline temperature difference relative to local ambient temperature ( C) (if IDENOP = 1) o dSALc: centerline salinity difference relative to local ambient salinity (ppt) (if IDENOP = 1) Flc: local densimetric Froude number (if IDENOP = 2)

In this mode CORJET becomes an important engineering tool for design sensitivity analysis --and also for research purposes-- to evaluate the behavior of the near-field processes to some of the ambient/discharge details, some of which had to be simplified (schematized) within the CORMIX approach. The user can learn to understand through repeated use of CORJET that plume mixing can indeed often be represented by simple linear, or even uniform, approximations to the ambient density structure.

Again, it is emphasized that CORJET when used al one is not a safe prediction methodology because of the limiting assumption of infinite receiving water. For that reason an alert is printed at the end of each CORJET output file:

Note: CORJET has been used outside the CORMIX system, assuming unlimited receiving water. Carefully examine all results for possible boundary effects due to surface, bottom, or lateral boundaries.

Previous application of CORMIX assures a careful examination of the interaction of the discharge with boundaries has been (b) Graphics display and plotting of CORJET results:

The graphical display and plotting of the CORJET prediction results by means of CMXGRAPH is similar to that of CORMIX results as described in Section 5.3.

The graphics package can be invoked in either access mode (within or outside of CORMIX) immediately after the computation or independently on any existing CORJET output file that has been computed earlier. Thus, CMXGRAPH has been configured to deal with both CORMIX prediction files and CORJET output files.

6.2 FFLOCATR: The Far-Field Plume Locator

6.2.1 General Features

Although the main emphasis of CORMIX is on the near-field mixing behavior of discharges it can also be used for providing plume predictions at larger distances in the far-field provided the flow is not highly irregular with pronounced recirculating zones and eddies in the ambient flow.

The CORMIX predicted far-field always applies to a rect angular schematized crosssection with a straight uniform channel (see Sections 4.3.1 and 4.3.2). The FFLOCATR is a simple method for interpreting the schematized CORMIX far-field plumes within the actual flow patterns in natural rivers and estuaries. This procedure, based on the cumulative discharge method, is illustrated in Figure 6.2.

The cumulative discharge method , first proposed by Yotsukura and Sayre (28; see also 19,20), is a convenient approach of dealing with lateral mixing in natural irregular (but not highly irregular with recirculating zones!) channels. In such channel geometry the passive far-field plume that is vertically mixed, or approaches vertical mixing, will be positioned around the “streamline”, or more precisely the “cumulative discharge line”, that passes through the plume

### ____________________________________________________________________________________

74 Figure 6.2: Illustration of the cumulative dischar g e method f or translating the COR M IX predicted f ar f ield plume to the actual f lo w characteristics in w inding irre g ular rivers or estuaries

### q ( y ) P y

0 

### u a 

### ( y ) H ( y ) dy

u a

75 center when it enters the far-field. Lateral Further technical details on the spreading around this line occurs by lateral FFLOCATR model can be found in the report on turbulent diffusion and can be enhanced CORMIX enhancements (8). buoyancy induced processes.

Looking downstream at a particular cross- 6.2.2 Access to FFLOCATR section (see Figure 6.2a) the cumulative discharge q(y) is defined as FFLOCATR can also be accessed in

in which y 1 is the lateral coordinate pointing from by entering the Post-Processor option in the right bank to the left across the flow ( y 1

differs the Iteration Menu. from y as defined in CORMIX whose origin is at the discharge location), H is the local depth, and (1b) It can be accessed on earlier is the depth-averaged local velocity. When the existing files by directly c hoosing the Postabove equation is integrated across the full Processor option in the Main Menu. channel width B then the total discharge will s result Q = q(B ) . Hence, if the local values q(y 1 ) In either case, once the a s are divided by Q the results can be presented in FFLOCATR option is chosen the user a normalized form as the cumulative discharge lines must first specify whether a CORMIX1, 2 ranging from 0% at the right bank to 100% at the or 3 simulation should be interpreted for left bank. The full distribution of such cumulative the far-field with FFLOCATR. Then the discharge lines in a river or estuary gives an CORMIX filename in the CORMIX\SIM appearance of the overall flow pattern that is directory must be specified. Finally, the important for pollutant transport. Closely spaced user must specify the name of the discharge lines are mostly indicative of areas of cumulative discharge input data file , or if large depth and higher velocities as they occur in that does not yet exist, the user can first the outside portion of river bends or meanders (as create such file by entering data on the sketched in Figure 6.2a). cumulative discharge distribution at

In the CORMIX schematization of ambient flow characteristics and channel cross-section it (2) Use outside CORMIX: is, in fact, useful to keep in mind the cumulative transport aspects of the ambient flow as remarked FFLOCATR can be invoked directly by in Section 4.3.1 and 4.3.2. Thus, the uniform typing the command line with three CORMIX flow field with the constant depth arguments: laterally is indeed conforming to a cumulative discharge distribution with equally spaced fflocatr CORMIXn fn POST\FF\ cumdata .FFI discharge lines, as indicated in Figure 6.2b. It is then conceptually straightforward to translate the (alternatively, ffl can be ty ped instead of CORMIX plume prediction back to the actual flow fflocatr) where CORMIXn, n = 1, 2 or 3, distribution by calculating and plotting the plume specifies which earlier CORMIX boundaries within the given cumulative discharge simulation should be analyzed for the farlines as shown in Figure 6.3c. The actual plume field, fn (without path and extension) is pattern may then show some surprising features the name of the CORMIX prediction file in such as strong “shifting back and forth” between the CORMIX\SIM directory, and cumdata opposing banks and an apparent “thinning’ of the (with directory desi gnation POST\FF and plume width. These realistic plume features are fixed extension FFI) is the cumulative simply dictated by the non-uniform flow field. discharge i nput data file (see following different ways:

(1) Use within CORMIX:

(1a) It can be accessed at an end of the prediction after the file has been stored,

several cross-sections.76 section) existing in directory In general, it is more convenient to CORMIX\POST\FF. construct the cumdata .FFI file outside of CORMIX and store it in the CORMIX\POST\FF directory. Alternatively if one types: This option is described first.

fflocatr (or simply: ffl)

without the three arguments, the model will prompt the user for the file information.

6.2.3 FFLOCATR Cumulative Discharge Input Data File (a) Input Data File Prepared Outside of CORMIX:

FFLOCATR is a Fortran program and reads the cumdata .FFI file in open format. An example is shown in Table 6.4 (corresponding to the test case discussed in Appendix B ).

Table 6.4 Example of a cumulative discharge input data file for FFLOCATR

SHALLOW RIVER CUMULATIVE DISCHARGE (applies to Sample2) Number of Cross-sections (XS): 3 XS 'Label-' Dist. 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

<> <------> <----> <---> <---> <---> <---> <---> <---> <---> <---> <---> <---> 1 'STA1' 30.5 6.1 12.2 15.9 20.7 27.5 33.6 58.0 76.3 82.4 88.5 2 'STA2' 152.5 9.2 16.8 21.4 24.4 27.5 33.6 36.6 39.7 54.9 79.3 3 'STA3' 305. 18.3 33.6 39.3 45.8 48.8 51.9 54.0 56.4 61.0 67.1

The required input data values (SI units) are:

Line 1: Any descriptive label. Line 2: <dummy line; not read> Line 3: NUMXS = Number of cross-sections (1 to 10) for which discharge data values will be entered Line 4: <dummy line useful for formatting subsequent data; not read> Line 5: <dummy line useful for formatting subsequent data; not read> Lines 6ff: NUMXS lines must be entered, each containing the following data: XS = number of cross-section, numbered sequentially beginning with 1 STALAB = arbitrary label for cross-section, bracketed by apostrophes ‘ with maximum total length of 10 characters (e.g. ‘RM595' standing for river mile 595) YCD = 10 values, representing the position of the cumulative discharge line (m) measured from the right bank, beginning with the 10% line, incrementing by 10%, and ending with the 100% line. The 100% line is also equal to the channel width at that cross-section.

Consistency checks are performed on each data file to make sure that the entered values YCD are monotonically increasing. Essentially two methods can be used for obtaining the values for the cumulative discharge positions YCD in specific cases: 1) On the basis of detailed stream-gaging surveys , for example using the standard methods employed by the U.S. Geological Survey. This is the preferable approach for small to medium streams or rivers.77 2) Using the results of detailed numerical models for the flow distribution in open channel flow. This is preferable for larger rivers or estuaries.

The primary application for FFLOCATR is for bounded channels such as streams, rivers or estuaries. The model will not execute when it encounters a CORMIX file for a design case involving an unbounded ambient flow.

Nevertheless, it may sometimes be useful to provide a detailed far-field plume delineation also for unbounded flow situations , such as coastal areas or lakes. This can be done when detailed hydrographic data or numerical model predictions describing the flow distribution in the near-shore where the plume may be located areavailable. A CORMIX simulation can then be rerun specifying a “bounded channel” with a width equal to some arbitrary bounding offshore streamline. The YCD data can then be specified relative to the value of that chosen streamline. FFLOCATR w ill thus predict the far-field plume location in the irregular coastal zone (assuming recirculating eddies do not exist in the flow).

(b) Input Data File Prepared Within CORMIX:

The user can generate the data file with exactly the same data structure as discussed above also within CORMIX. The system will prompt the user for the individual data items (up to 10 cross-sections can be entered) and t hen for

a cumdata filename. The file will then be stored automatically in directory CORMIX\POST\FF with extension FFI.

6.2.4 FFLOCATR Output Features

FFLOCATR generates an output file CORMIX\POST\FF\ fn

.FFX indicating that the farfield plume prediction for the CORMIX design case fnhas been interpreted under the actual farfield flow distribution. This file can be inspected on-screen when in CORMIX or externally with any text processor, and can be printed out. No graphics plotting option exists for this file.

As an example, Table 6.5 on the next page shows the output file that combines the cumulative discharge input data of Table 6.4 with the CORMIX2 plume predictions that are part of Appendix B . The output file preceded by the banner ‘FFF’ consists of three parts. The first part lists some of the underlying CORMIX data including file information. The second part echoes the complete cumulative discharge input data file.

The actual results of the FFLOCATR translation routine are given in the third part. For each of the specified cross-sections (stations) the output file lists the station label, the downstream distance, and the position of plume center, left edge and right edge, respectively, each measured from the right bank, and the local centerline dilution and concentration. Data of this kind can then r eadily be used to prepare plots of far-field plumes superimposed on maps of the actual flow field. This last step has been illustrated in Figure 6.2c.

It should be understood that the plume centerline in the far-field does not necessarily coincide with the cumulative discharge line that passes through the offshore discharge location(as has been illustrated in Figure 6.2 where a coflowing discharge had been assumed). The plume centerline can shift because of near-field processes, as in case of a cross-flowingdischarge, or if bank interaction occurs in the farfield, causing the centerline to shift to one bank/shore.78 Table 6.5 Example of FFLOCATR output file

FFLOCATR RESULTS FILE: FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF FFLOCATR: FAR-FIELD PLUME LOCATOR Version 1.0, March 1994

---------------------------------------------------------------------------- Output FILE NAME: POST\FF\SAMPLE2.FFX Time of FFLOCATR run: 1995/ 6/ 2-- 8:54:38

---------------------------------------------------------------------------- FAR-FIELD DATA values from earlier CORMIX2 prediction: FILE NAME: SIM\SAMPLE2.cx2 Site name/label: B-PLANT^SHALLOW-RIVER Design case: LOW-FLOW^7Q10 Time of CORMIX2 run: 09/20/94--15:24:11

Channel characteristics (metric): BS = 50.00 HA = .30 UA = .54 BANK = right DISTB = 20.00 STRCND= U uniform density environment

Pollutant data: C0 = 100.00 CUNITS= PERCENT

---------------------------------------------------------------------------- CUMULATIVE DISCHARGE DATA (m): FILE NAME: POST\FF\SH-RIVER.ffi Data label: SHALLOW RIVER CUMULATIVE DISCHARGE Number of XS: 3 XS'Label-' Dist. 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 1 'STA1 ' 30.5 6.10 12.20 15.90 20.70 27.50 33.60 58.00 76.30 82.40 88.00 2 'STA2 ' 152.5 9.20 16.80 21.40 24.40 27.50 33.60 36.60 39.70 54.90 79.00 3 'STA3 ' 305.0 18.30 33.60 39.30 45.80 48.80 51.90 54.00 56.40 61.00 67.00

---------------------------------------------------------------------------- FAR-FIELD PLUME PROPERTIES (m): XS 'Label-' Distance Left Plume Right Dilution Conc. # downstream edge centerline edge 1 'STA1 ' 30.50 27.50 20.70 13.28 30.1 .332E+01 2 'STA2 ' 152.50 27.50 24.40 17.80 31.4 .318E+01 3 'STA3 ' 305.00 48.80 45.80 34.32 33.0 .303E+01

---------------------------------------------------------------------------- END OF FFLOCATR: FAR-FIELD PLUME LOCATOR FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF79 

## VII Closure

7.1 Synopsis

The Cornell Mixing Zone Expert System (CORMIX) is a series of software subsystems for The CORMIX system programs can be the analysis, prediction, and design of aqueous obtained from: toxic or conventional pollutant discharges into diverse water bodies. The major emphasis is on U.S. EPA - Center for Environmental the geometry and dilution characteristics of the Assessment Modeling (CEAM) initial mixing zone including compliance with Environmental Research Laboratory regulatory constraints. The system also predicts 960 College Station Road the behavior of the discharge plume at larger Athens, GA 30605-2700 USA distances in the far-field. Tel. 706-546-3549 (or FTS 250-3590)
The highly user-interactive CORMIX E-mail: ceam@athens.ath.epa.gov system is implemented on IBM-PC compatible microcomputers and consists of three As of the release of this manual (late 1996) the subsystems. These are: CORMIX1 for following versions of CORMIX are available: submerged single port discharges, CORMIX2 for CORMIX Version2.1 (1993, wit hout graphics and submerged multiport diffuser discharges and post-processor features) and Version3.1 (August CORMIX3 for buoyant surface discharges. The 1996, as described in this report). The models basic CORMIX methodology relies on the can be obtained by mail or over the electronic assumption of steady ambient conditions. bulletin board operated by CEAM. Information on However, recent versions also contain special program installation and computer configuration routines for the application to highly unsteady are also provided by CEAM. The ftp address is: environments, such as tidal reversal conditions, in which transient recirculation and pollutant build-up effects can occur.

In addition, two post-processing models are linked to the CORMIX system, but can also be used independently. These are CORJET (the Cornell Buoyant Jet Integral Model) for the detailed analysis of the near-field behavior of buoyant jets, and FFLOCATR (the Far-Field Plume Locator) for the far-field delineation of discharge plumes in non-uniform river or estuary environments.

This user's manual gives a comprehensive and uniform description of all three CORMIX subsystems; it provides advice for assembly and preparation of required input data; it delineates ranges of applicability of the three subsystems; it provides instruction for the interpretation and graphical display of system output; and it illustrates practical system application through several case studies. 7.2 System and Documentation Availability

Fax:706-546-3402

ftp://ftp.epa.gov/epa_ceam/wwwhtml/ceamhome.htm

The distribution versions of CORMIX contain only the executable code of the FORTRAN programs HYDROn; they do not include the source code. The source code can be requested separately by writing to CEAM at U.S. EPA-ERL and giving the reason for code inspection and possible manipulation. The full code, while m ade up of simple individual modules, is complex with multiple interdependencies; only experienced research personnel should attempt this work when engaged in comparison of model predictions to new field or laboratory data.

The technical documentation reports(5,6,7,8) are available as U.S. EPA and NITS publications, and have also been issued as technical reports of the DeFrees Hydraulics Laboratory.80 7.3 User Support

Technical and scientific support for COR M I X under contract from the USEPA is provided b y :

Dr. Robert L. Doneker Department of Environmental Science and Engineering Oregon Graduate Institute PO Box 91000 Portland, OR 97291-1000

T el. 503-690-4053, Fax. 503-690-1273 email: doneker@ese.ogi.edu

T his includes assistance on problems of s y stem i n s tallation and execution, and advice on the specification of input data as w ell a s interpretation of COR M I X output.

An y high-qualit y field or laborator y

data on

e f fluent mixing processes is a valuable asset for

an y future development or updates on COR M I X

. T r an s m i tt a l of such data to the follo w ing address will be greatl y appreciated:

Prof. Gerhard H. Jirka Institute for H y dromechanics Universit y of Karlsruhe PO Box 6380 D-76128 Karlsruhe, GER M AN Y

T el. (49) 721/608-2200, Fax. (49) 7 2 1 / 6 6

- 1 6

- 8 681 

## Literature References

(1) "Technical Support Document for Water (8) Jirka, G.H., P.J. Akar and J.D. Nash, Quality-based Toxics Control," U.S. EPA, “Enhancements to the CORMIX Mixing Office of Water, Washington, DC, Zone Expert System: Technical September, 1991. Background”, Tech. Rep., DeFrees

(2) "Assessment and Control of Environmental Engineering, Cornell Bioconcentratable Contaminants in University, 1996, (also to be published by Surface Waters," U.S. EPA, Office of U.S. Environmental Protection Agency, Water, Washington, DC, March, 1991. Tech. Rep., Environmental Research Lab,

(3) Jirka, G. H., "Use of Mixing Zone Models in Estuarine Waste Load Allocation," Part (9) Doneker, R.L. and G.H. Jirka, "Expert III of Technical Guidance Manual for Systems for Design and Mixing Zone Performing Waste Load Allocations , Book Analysis of Aqueous Pollutant III: Estuaries, Ed. by R. A. Ambrose and J. Discharges", J. Water Resources L. Martin, U.S. EPA, Washington, D.C., Planning and Management , ASCE, Vol. EPA-823-R-92-004, 1992. 117, No.6, 679-697, 1991.

(4) Muellenhoff, W. P., et al .,"Initial Mixing (10) Jirka G. H. and R. L. Doneker, Characteristics of Municipal Ocean "Hydrodynamic Classification of Discharges (Vol I & II)," USEPA, Submerged Single Port Discharges", J. Environmental Research Laboratory, Hydraulic Engineering , ASCE, Vol.117, Narragansett, RI, 1985. 1095-1112, 1991.

(5) Doneker, R. L., and G. H. Jirka, (11) Jirka G. H. and P. J. Akar, "Hydrodynamic "CORMIX1: An Expert System for Mixing Classification of Submerged Multiport Zone Analysis of Conventi onal and Toxic Diffuser Discharges," J. Hydraulic Single Port Aquatic Discharges", U.S. Engineering , ASCE, (117), 1113-1128, EPA, Environmental Research HY9, 1991. Laboratory, Athens, GA, EPA- 600/600/3- 90/012, 1990. (12) Akar, P.J. and G.H. Jirka, "Buoyant

(6) Akar, P. J. and G. H. Jirka, "CORMIX2: An Transport and Mixing. Part I: Lateral Expert System for Hydrodynamic Mixing Spreading in Strong Ambient Current", J. Zone Analysis of Conventi onal and Toxic Hydraulic Research , Vol. 32, 815-831, Submerged Multiport Discharges," U.S. 1994. EPA, Environmental Research Laboratory Athens, GA, EPA/600/3-91/073, 1991. (13) Akar, P.J.and G.H. Jirka, "Buoyant

(7) Jones, G.R., J.D. Nash and G.H. Jirka, Transport and Mixing. Part II: Upstream "CORMIX3: An Expert System for Mixing Spreading in Weak Ambient Current", J. Zone Analysis and Prediction of Buoyant Hydraulic Research , Vol. 33, 87-100, Surface Discharges", Tech. Rep., 1995. DeFrees Hydraulics Laboratory, School of Civil and Environmental Engineering, (14) Mendéz Díaz, M.M. and G.H. Jirka, Cornell University, 1996, (also to be "Trajectory of Multiport Diffuser published by U.S. Environmental Discharges in Deep Co-Flow", J. Protection Agency, Environmental Hydraulic Engineering, ASCE, Vol.122, Research Lab, Athens, GA). HY6, 1996 (in press). Hydraulics Laboratory, School of Civil and

Athens, GA).

Spreading Processes in Pollutant

Spreading Processes in Pollutant82 (15) Jones, G.R., J.D. Nash and G.H. Jirka, (22) "Technical Guidance Manual for the "Buoyant Surface Discharges into Water Regulations Promulgated Pursuant to Bodies, Part 1: Classification," J. Section 301 (g) of the Cl ean Water Act of Hydraulic Engineering , ASCE, (submitted 1977 (Draf t)," U.S. EPA, Washington, DC, 1996). August, 1984.

(16) Jones, G.R. and G.H. Jirka, "Buoyant (23) "Revised Section 301 (h) Technical Surface Discharges into Water Bodies, Support Document," EPA 430/9-82-011, Part 2: Prediction," J. Hydraulic U.S. EPA, Washington, DC, 1982. Engineering , ASCE, (submitted 1996).

(17) J.D. Nash and G.H. Jirka, "Buoyant McGraw-Hill, New York, 1959. Surface Discharges into Unsteady Ambient Flows", Dynamics of (25) Jirka, G.H. and Fong, H.L.M., "Vortex Atmospheres and Oceans , 24, 75-84, Dynamics and Bifurcation of Buoyant Jets 1996. in Crossflow", J. Engineering Mechanics

(18) Jirka G. H., "Multiport Diffusers for Heat 1981. Disposal: A Summary," J. Hydraulics Division , ASCE, (108), HY12, pp. 1423- (26) Jirka, G.H., "Single and Multiple Buoyant 68, 1982. Jets in Crossflow", J. Hydraulic Research,

(19) Holley, E. R. and G. H. Jirka, "Mixing in Rivers," Technical Report E-86-11, U.S. (27) Baumgartner, D.J., W.E. Frick and P.J.W. Army Corps of Engineers, Washington, Robert, “Dilution Models for Effluent DC, 1986. Discharges (Third Edition)”, U.S. EPA,

(20) Fischer, H. B. et al ., Mixing in Inland and OR, EPA/600/R-94/086, 1994. Coastal Waters, Academic Press, New York, 1979. (28) Yotsukura, N. and W.W. Sayre,

(21) "Water Quality Standards Handbook," Water Resources Research, Vol.12, 695- U.S. EPA, Office of Water Regulations 704, 1976. and Standards, Washington, DC, 1984. (24) Chow, V. T., Open Channel Hydraulics

,

Division , ASCE, Vol.107, pp. 479-499,

(submitted 1996).

Pacific Ocean Systems Branch, Newport,

“Transverse mixing in natural channels”,83 

## Appendix A

Flow Classification Diagrams for the Three CORMIX Subsystems

CORMIX1: Submerged Single Port Discharges ........................................................84

CORMIX2: Submerged Multiport Diffuser Discharges ...............................................88

CORMIX3: Buoyant Surface Discharges ...................................................................91

### 9293 

## Appendix B CORMIX1: Submerged Single Port Discharge in a Deep Reservoir

This case study illustrates the application The stratification can be expected to be of CORMIX1 to the prediction of the effluent from horizontally uniform and therefore similar a small manufacturing plant into a large and deep c onditions w ill hold at the discharge site. Also, stratified reservoir. the river inflow is colder than the surface layer of

B.1 Problem Statement

A manufacturing plant (A-Plant) is discharging its effluent into an adjacent deep reservoir. The plant design flowrate is 3.5 mgd (  0.15 m /s). The effluent contains heavy metal at 3 a concentration of 3500 ppb, and is released at a temperature of 68 F (= 20 C). The density of the o o effluent at this low concentration can be considered equivalent to freshwater.

The existing reservoir has been formed by flooding a river valley. The reservoir l ength is about 60 miles. The water level in the reservoir is fluctuating depending on the release operation at the downstream dam with its hydropower installation. During summer conditions, the reservoir level is typically at an elevation of 710 ft above sea level. This results in a reservoir width of about 4000 ft (  1200 m) and a maximum depth of 310 ft (  95 m) at the discharge location. The mean river flow into the reservoir during the summer low-flow conditions is about 18,540 cfs (  525 m /s). The typical temperature of the 3 inflowing river water is 55 F (  13 C). o o

Figure B.1 shows the local bathymetry (as obtained from a USGS map) in the vicinity of the proposed discharge. Since the discharge is very small relative to the reservoir size and the ambient flowrate, it is expected that mostly local conditions w ill be important, and not overall reservoir dimensions. (Note: Any such conjecture has to be verified against the final B.2 Problem Schematization and Data simulation results, and adjustments have to be made if needed.)

Temperature data as a function of depth obtained from field measurements in the center of the reservoir show a significant temperature stratification (see Figure B.2), as is typical for such deep reservoirs during summer conditions. the stratified reservoir. The reservoir has a selective withdrawal structure at the dam, therefore it can be expected that the river water will flow predominantly in a vertically limited layer, that may extend from a depth of about 35 m to the surface. The velocity of that flow is estimated at about 1.5 cm/s (  0.015 m/s), given the 35 m thick layer and an about 1000 m width at that elevation. (Note: More detailed hydrodynamic investigations, using available models for stratified reservoir dynamics, can be used to obtain more precise estimates of the velocity field. Generally, however, it cannot be assumed that the velocity in stratified reservoirs is given by the simple average of the flowrate divided by the cross-sectional area.)

The proposed discharge location on the side slope of the cross-section is also shown in Figure B.1: a submerged single port discharge at an elevation of 610 ft above sea level, i.e. at a local depth of 100 ft (  30.5 m) below the surface, is proposed in the initial design phase. The port diameter is 10 in (  0.254 m) and is located 2 ft (  0.6 m) above the local bottom. The discharge is pointing offshore and is angled upward at 10 . o

The discharge is subject to State mixing zone regulations whereby the mixing zone width is less than 10% of the width of the water body. Furthermore, the heavy metal in the effluent is considered toxic with CMC and CCC limits of 1200 and 600 ppb, respectively.

Preparation

Figure B.3 is the data checklist that summarizes the CORMIX1 input for the present problem. The ambient water body has been characterized as unbounded in line with the expectation that the discharge plume will be small

### 94 Figure B.1: Local details of Deep Reservoir cross-section and CORMIX1 schematization

Figure B.2: Temperature field data as a function of depth and CORMIX1 representation of Type C temperature profile96 in size relative to the reservoir width. here). The detailed plume properties are Furthermore, since (1) the discharge elevation is computed in program element HYDRO, and are well above the lowest point of the reservoir and displayed in the Fortran CORMIX1 prediction file (2) the plume is expected to rise toward the (see Table B.2, discussed in more detail further surface, the ambient water depth is taken as 150 below). ft (  35.0 m) only.

The depth at the discharge corresponds to prediction are summarized in program element the local depth at the discharge location. SUM of the session record (see Table B.1). Because of the sloping bank from the discharge Notably, all aspects pertaining to mixing zone to the near shoreline, the distance to bank (46 m) r egulations are contai ned in that summary. For corresponds to one-half of the actual distance example, it can be seen quickly from that from the outlet to the shoreline at the water summary that the present discharge configuration surface. The ambient velocity corresponds to the meets all three toxic dilution z one (TDZ) criteria estimate made above for the stratified water body. and also the r egulatory mixing zone (RMZ) A Manning's n of 0.02 describes the smooth limitation. Obviously, other ambient conditions bottom. and discharge variations should be considered in

Density data is simply entered via the this should be deemed fully satisfactory. temperature values of the fresh water body. A Stratification Type C is chosen to describe the actual temperature profile.

The discharge data values summarize the discharge situation as described above. Finally, the mixing zone specifications include a width value of 120 m, corresponding to 10 % of the actual width of 1200 m. Information is desired over about one mile (  1600 m) which represents the region of interest (ROI) limitation.

B.3 CORMIX1 Session and Results

If desired by the user, CORMIX1 provides a summary of the data as they are entered, and then a full record of the simulation s equence and final results. This session summary report is shown in Table B.1. Of particular interest to the user are the evaluations in program element PARAM and CL ASS. Note, that the computed length scales L ' and L ' are quite small, m b indicating that the jet or plume will be trapped quickly by the ambient stratification; thus, this is the first numerical indication that the near-field jet/plume will indeed be small relative to the reservoir. The ambient flow related scales L and m L are quite large, indicating that the ambient

b velocity is very weak. The resulting flow class S3 is dominated by the ambient stratification; the plume will be limited to the lower layer of the stratification. The user should also consult the description of flow class S3 that is available during the CORMIX1 session (not reproduced Many important features of the plume

additional simulations before a design such as

B.4 Graphical Displays of Detailed Plume Predictions

As for most engineering studies it is desirable to produce graphical displays for visualization of the predicted results. The data contained in the CORMIX1 prediction file (Table B.2) form the basis for such plots. Unfortunately, it is often difficult to display all plume features in one single plot because the plume may contain a lot of near-field details while extending over large distances into the far-field. A short examination of Table B.2 proves that point: The plume gets quickly trapped within a very limited near-field but with considerable mixing (see MOD110 = CORJET of the CORMIX1 prediction). Yet after that the plume extends over large distances into the far-field forming a wide thin layer within the stratified reservoir (see MOD142).

Using the graphics package CMXGRAPH, two plots have been prepared to display the jet/plume side view in the near-field, using distorted and undistorted 1:1 scales, respectively, (Figure B.4) and the plan view in the near-field and larger scale far-field (Figure B.5) of the effluent plume. Figure B.4 shows the initial trajectory of the slightly upward curved jet that rises to maximum level of 4.29 m and then gets trapped at an elevation of 3.44 m above the local bottom. In the trapping stage the jet under goes a complicated transition (MOD137) to the horizontally spreading layer. CORMIX1 predicts99 Table B.2 CORMIX1 Prediction File for A-Plant discharge into Deep Reservoir with summer stratification

CORMIX1 PREDICTION FILE: 11111111111111111111111111111111111111111111111111111111111111111111111111111 CORNELL MIXING ZONE EXPERT SYSTEM Subsystem CORMIX1: Subsystem version: Submerged Single Port Discharges CORMIX_v.3.1__________June_1995

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- CASE DESCRIPTION Site name/label: DEEP^RESERVOIR Design case: A-PLANT^SUMMER^STRATIFICATION FILE NAME: cormix\sim\SAMPLE1 .cx1 Time of Fortran run: 06/24/95--22:29:54

ENVIRONMENT PARAMETERS (metric units) Unbounded section HA = 35.00 HD = 30.50 UA = .015 F = .010 USTAR = .5200E-03 UW = 2.000 UWSTAR= .2198E-02 Density stratified environment STRCND= C RHOAM = 997.6240 RHOAS = 996.2053 RHOAB = 999.6072 RHOAH0= 999.5599 E = .7730E-03 DRHOJ = 2.1813 HINT = 15.50 ES = .2153E-02

DISCHARGE PARAMETERS (metric units) BANK = RIGHT DISTB = 46.00 D0 = .254 A0 = .051 H0 = .60 THETA = 10.00 SIGMA = 90.00 U0 = 3.020 Q0 = .153 = .1530E+00 RHO0 = 998.2051 DRHO0 = .1355E+01 GP0 = .1329E-01 C0 = .3500E+04 CUNITS= PPB IPOLL = 1 KS = .0000E+00 KD = .0000E+00

FLUX VARIABLES (metric units) Q0 = .1530E+00 M0 = .4620E+00 J0 = .2034E-02 SIGNJ0= 1.0 Associated length scales (meters) LQ = .23 LM = 12.43 Lm = 45.31 Lb = 602.57 Lmp = 4.94 Lbp = 3.12

NON-DIMENSIONAL PARAMETERS FR0 = 51.96 R = 201.30

FLOW CLASSIFICATION 111111111111111111111111111111111111111111 1 Flow class (CORMIX1) = S3 1 1 Applicable layer depth HS = 15.50 1 111111111111111111111111111111111111111111

MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS C0 = .3500E+04 CUNITS= PPM NTOX = 1 CMC = .1200E+04 CCC = CSTD NSTD = 1 CSTD = .6000E+03 REGMZ = 1 REGSPC= 2 XREG = .00 WREG = 120.00 AREG = .00 XINT = 3500.00 XMAX = 3500.00

X-Y-Z COORDINATE SYSTEM: ORIGIN is located at the bottom and below the center of the port: 46.00 m from the RIGHT bank/shore. X-axis points downstream, Y-axis points to left, Z-axis points upward. NSTEP = 20 display intervals per module

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD101: DISCHARGE MODULE

X Y Z S C B .00 .00 .60 1.0 .350E+04 .13

END OF MOD101: DISCHARGE MODULE

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN CORJET (MOD110): JET/PLUME NEAR-FIELD MIXING REGION100 Jet-like motion in linear stratification with weak crossflow.

Zone of flow establishment: THETAE= 10.00 SIGMAE= 89.45 LE = 1.25 XE = .01 YE = 1.23 ZE = .82

Profile definitions: B = Gaussian 1/e (37%) half-width, normal to trajectory S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any)

X Y Z S C B .00 .00 .60 1.0 .350E+04 .13 .01 1.23 .82 1.0 .350E+04 .14 .02 2.30 1.01 1.7 .205E+04 .26 .04 3.48 1.23 2.6 .136E+04 .39 ** CMC HAS BEEN FOUND ** The pollutant concentration in the plume falls below CMC value of .120E+04 in the current prediction interval. This is the extent of the TOXIC DILUTION ZONE. .08 4.67 1.45 3.5 .101E+04 .53 .13 5.97 1.72 4.4 .790E+03 .67 .18 7.14 1.97 5.3 .658E+03 .80 ** WATER QUALITY STANDARD OR CCC HAS BEEN FOUND ** The pollutant concentration in the plume falls below water quality standard or CCC value of .600E+03 in the current prediction interval. This is the spatial extent of concentrations exceeding the water quality standard or CCC value. .24 8.32 2.24 6.2 .564E+03 .94 .32 9.49 2.52 7.1 .493E+03 1.07 .40 10.65 2.81 8.0 .437E+03 1.21 .49 11.82 3.10 8.9 .393E+03 1.34 .60 12.99 3.39 9.8 .357E+03 1.48 .71 14.15 3.66 10.7 .328E+03 1.61 .84 15.33 3.90 11.6 .303E+03 1.75 .98 16.51 4.09 12.4 .281E+03 1.89 1.13 17.70 4.23 13.3 .262E+03 2.03 1.27 18.77 4.29 14.2 .247E+03 2.15 Maximum jet height has been reached. 1.45 19.96 4.27 15.1 .232E+03 2.29 1.63 21.15 4.16 16.1 .218E+03 2.43 1.83 22.32 3.97 17.1 .205E+03 2.57 2.04 23.48 3.72 18.1 .193E+03 2.71 2.26 24.63 3.44 19.1 .183E+03 2.85 Terminal level in stratified ambient has been reached. Cumulative travel time = 63. sec

END OF CORJET (MOD110): JET/PLUME NEAR-FIELD MIXING REGION

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD137: TERMINAL LAYER INJECTION/UPSTREAM SPREADING

UPSTREAM INTRUSION PROPERTIES: Maximum elevation of jet/plume rise = 7.64 m Layer thickness in impingement region = 1.29 m Upstream intrusion length = 90.24 m X-position of upstream stagnation point = -87.99 m Thickness in intrusion region = 1.29 m Half-width at downstream end = 191.87 m Thickness at downstream end = .95 m

Control volume inflow: X Y Z S C B 2.26 24.63 3.44 19.1 .183E+03 2.85

Profile definitions: BV = top-hat thickness, measured vertically BH = top-hat half-width, measured horizontally in Y-direction ZU = upper plume boundary (Z-coordinate) ZL = lower plume boundary (Z-coordinate) S = hydrodynamic average (bulk) dilution C = average (bulk) concentration (includes reaction effects, if any)

X Y Z S C BV BH ZU ZL -87.99 24.63 3.44 9999.9 .000E+00 .00 .00 3.44 3.44 -84.26 24.63 3.44 75.2 .465E+02 .33 27.13 3.60 3.27 -66.02 24.63 3.44 31.3 .112E+03 .79 65.91 3.83 3.04101 -47.77 24.63 3.44 23.8 .147E+03 1.04 89.17 3.96 2.92 -29.53 24.63 3.44 20.8 .169E+03 1.19 107.51 4.03 2.84 -11.28 24.63 3.44 19.4 .180E+03 1.28 123.15 4.07 2.80 6.96 24.63 3.44 19.3 .181E+03 1.29 137.02 4.08 2.79 25.21 24.63 3.44 22.5 .155E+03 1.22 149.61 4.05 2.82 43.45 24.63 3.44 27.7 .126E+03 1.11 161.21 3.99 2.88 61.70 24.63 3.44 32.1 .109E+03 1.02 172.04 3.95 2.93 79.95 24.63 3.44 34.4 .102E+03 .97 182.22 3.92 2.95 98.19 24.63 3.44 35.6 .982E+02 .95 191.87 3.91 2.96 Cumulative travel time = 6459. sec

END OF MOD137: TERMINAL LAYER INJECTION/UPSTREAM SPREADING

----------------------------------------------------------------------------- ** End of NEAR-FIELD REGION (NFR) **

In this design case, the discharge is located CLOSE TO BANK/SHORE. Some boundary interaction occurs at end of near-field. This may be related to a design case with a very LOW AMBIENT VELOCITY. The dilution values in one or more of the preceding zones may be too high. Carefully evaluate results in near-field and check degree of interaction.

Consider locating outfall further away from bank or shore. In the next prediction module, the plume centerline will be set to follow the bank/shore. ** REGULATORY MIXING ZONE BOUNDARY is within the Near-Field Region (NFR) **

----------------------------------------------------------------------------- BEGIN MOD142: BUOYANT TERMINAL LAYER SPREADING

Plume is ATTACHED to RIGHT bank/shore. Plume width is now determined from RIGHT bank/shore.

Profile definitions: BV = top-hat thickness, measured vertically BH = top-hat half-width, measured horizontally in Y-direction ZU = upper plume boundary (Z-coordinate) ZL = lower plume boundary (Z-coordinate) S = hydrodynamic average (bulk) dilution C = average (bulk) concentration (includes reaction effects, if any)

Plume Stage 2 (bank attached): X Y Z S C BV BH ZU ZL 98.19 -46.00 3.44 35.6 .982E+02 1.38 262.50 4.13 2.74 268.28 -46.00 3.44 42.7 .820E+02 .93 468.27 3.90 2.97 438.37 -46.00 3.44 48.4 .722E+02 .81 609.62 3.84 3.03 608.46 -46.00 3.44 54.7 .640E+02 .77 728.17 3.82 3.05 778.55 -46.00 3.44 61.7 .568E+02 .75 836.14 3.81 3.06 948.64 -46.00 3.44 69.2 .505E+02 .75 938.66 3.81 3.06 1118.73 -46.00 3.44 77.3 .453E+02 .76 1038.24 3.82 3.06 1288.82 -46.00 3.44 85.9 .408E+02 .77 1136.20 3.82 3.05 1458.91 -46.00 3.44 94.8 .369E+02 .78 1233.26 3.83 3.04 1629.00 -46.00 3.44 104.0 .336E+02 .80 1329.86 3.84 3.04 1799.10 -46.00 3.44 113.6 .308E+02 .81 1426.23 3.84 3.03 1969.19 -46.00 3.44 123.4 .284E+02 .83 1522.53 3.85 3.02 2139.28 -46.00 3.44 133.5 .262E+02 .84 1618.85 3.86 3.02 2309.37 -46.00 3.44 143.8 .243E+02 .86 1715.24 3.86 3.01 2479.46 -46.00 3.44 154.4 .227E+02 .87 1811.74 3.87 3.00 2649.55 -46.00 3.44 165.2 .212E+02 .88 1908.37 3.88 2.99 2819.64 -46.00 3.44 176.2 .199E+02 .90 2005.12 3.88 2.99 2989.73 -46.00 3.44 187.4 .187E+02 .91 2102.02 3.89 2.98 3159.82 -46.00 3.44 198.7 .176E+02 .92 2199.06 3.90 2.98 3329.91 -46.00 3.44 210.3 .166E+02 .93 2296.24 3.90 2.97 3500.00 -46.00 3.44 222.1 .158E+02 .95 2393.56 3.91 2.96 Cumulative travel time = 233246. sec

Simulation limit based on maximum specified distance = 3500.00 m. This is the REGION OF INTEREST limitation.

END OF MOD142: BUOYANT TERMINAL LAYER SPREADING

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- CORMIX1: Submerged Single Port Discharges End of Prediction File 11111111111111111111111111111111111111111111111111111111111111111111111111111

### 102 Figure B.4: Different side views of near-field jet/plume discharge in stratified reservoir. a) distorted unscaled view, b) view with fixed undistorted scale, and c) undistorted view along trajectory (in the x-y plane).

### 103 Figure B.5: Plan view of diffuser plume in a) complete field (near- and far), and b) near-field only. (Note: since in this simulation the discharge was schematized as an unbounded cross-section, theresulting plume would actually contact far shoreline when the plume width exceeds the actual crosssection width of 1000 m. This occurs when BH ≅ 1000 m at x ≅ 1000 m downstream as shown in view a). Thus, if plume concentration data were required after far shoreline contact, a bounded cross-section would need to be specified (BS = 1000) in a new simulation

.

### ____________________________________________________________________________________

104 Figure B.6: Concentration distribution as a function of distance along plume centerline

a few parameters such as the upstream intrusion length, downstream width, and shape of the intrusion. As indicated in Figure B.5, reasonable transition boundaries can be assumed to provide smooth transitions to the far-field processes.

The side and plan views show the wide and thin layer that forms as the plume collapses laterally within the ambient stratification while it is advected by the weak ambient flow.

Some discontinuity in the predicted plume dimensions occurs in the transition from the control volume (MOD137) describing upstream spreading to the continuous prediction for ambient buoyant spreading (MOD142). The cause for this discontinuity is the simultaneous interaction of the plume with the channel boundary that occurs within MOD137. CORMIX1 detects such complicated simultaneous processes and warns the user who then can compensate by providing reasonable, mass-conserving transitions. It is also possible to include concentration values, e.g. along the centerline, in plots of this type. This has not been done in these figures in order not to overload them. Alternatively, the concentration distribution following the centerline of the plume is plotted in Figure B.6. The rapid drop-off within the initial buoyant jet region is evident. Also, the thresholds for all water quality parameters and module boundaries have been exercised in the plot. Hence, the locations where the CMC (i.e. TDZ) and CCC values are met have been indicated.

B.5 Details of Buoyant Jet Near-field Mixing

The CORJET model option can be employed if further details within the very initial buoyant jet motion are desired. This option can be exercised internally at the conclusion of theCORMIX design case by choosing the postprocessor. The CORJET output corresponding to this has alr eady been shown as an example in105 Section 6.1, namely as Table 6.2. That output approximations to the ambient density profile agrees well with that listed in Table B.2. and/or velocity distribution. The r eader is

More importantly, CORJET could also be the procedures explained in Section 6.1 and used separately to examine different illustrated in Appendix E. encouraged to explore this approach, following106107 

## Appendix C CORMIX1 and 2: Submerged Single Port Discharge and Multiport Diffuser in a Shallow River

The design modification of an existing the discharge reach. River cross-sections were (hypothetical situation) discharge from a plant into determined by depth measurements at several a shallow river is considered in this case study. stations as indicated. For example, Figure C.2 This affords an opportunity to demonstrate the gives the cross-section at the discharge location.joint use of CORMIX and of a dye field study in All cross-sections exhibit quite some nonorder to analyze an existing effluent plume from a uniformity as is typical for a gently meandering single port discharge and to suggest a design alluvial (gravel) river. The indicated water level conversion to a multiport diffuser with improved corresponds to the river discharge of 840 cfs (  mixing characteristics. 23.7 m /s) that was measured during the field

C.1 Problem Statement

An industrial plant (B-Plant) is currently discharging its effluent into an adjacent shallow river. The design flowrate is quite small at 2.1 mgd (  0.092 m /s). The river is about 200 to 300 3 ft wide at the discharge location and the following downstream reach. Water depth is, of course, depen dent on the river discharge that is seasonally variable. An examination of available streamflow records (USGS data) suggests a 7Q10 low flow discharge of 285 cfs (  8.06 m /s). 3

Recent water quality studies in the discharge reach performed during low flow summer conditions have shown occasional coloration problems in the discharge plume that seem to be related to inadequate mixing characteristics of the present submerged single port discharge. For that reason the plant operator is considering an improvement of the discharge structure.

C.2 Existing Single Port Discharge: Dye Field Study and CORMIX1 Comparison

An initial field study was conducted in order (1) to measure the geometric and hydraulic characteristics of the discharge reach with special emphasis on the first 1000 ft downstream, and (2) to determine plume concentrations by means of a dye injection into the plant effluent.

Figure C.1 shows the plan geometry of 3 survey using the usual USGS stream-gaging methods. The ambient temperature at this flowrate was 20 C. The discharge pipe (diameter o = 8 in  0.2 m) is located about 95 ft from the right bank, and is pointing in the downstream direction.

In order to obtain a detailed description of the flow field in the river, reach discharge measurements were conducted at several more downstream stations (200, 400, 750, and 1000 ft, respectively). Figure C.1 includes the cumulative discharge isolines, expressed in % of the total discharge as measured from the right bank, for the reach. These lines provide a useful indication of the mean flow pattern in such a winding river for subsequent interpretation of observed plume features (see also comments on cumulative discharge method in Section 6.2).

A dye test was carried out by continuously discharging a fluorescein dye solution into the plant effluent. The dye concentration exiting the discharge pipe was 560 ppb with a temperature of 22 C. Dye concentration were measured at the o transects indicated in Figure C.1, and have been plotted in Figure C.3 as a function of distance from the right bank. The observed concentration profiles show decreasing peak (maximum) values with increasing downstream distances. Observations indicated a vertically mixed plume at all locations. In the display of Figure C.3 the plume centerline position is clearly shifting relative to the right bank, and the plume width occasionally appears to slightlycontract in width.

An initial CORMIX1 evaluation was carried out to ascertain its applicability in this somewhat

### 108 Figure C.1: Plan view of downstream reach of Shallow River with cumulative discharge measurement stations and distribution

Figure C.2: River cross-section at discharge location

### 109 Figure C.3: Measured dye concentration plotted as a function of distance from right bank

irregular flow environment. For this purpose, the cross-section was schematized as a rectangular cross-section putting emphasis on the depth conditions around the discharge location. The average and local depths at this flow rate are both 1.9 ft or (» 0.6 m).

Information from the cumulative discharge data was used. Note that the cumulative discharge data shows the discharge located at the 60 % line, i.e. it is hydraulically closer to the left bank, while it appears geographically closer to the right! This is reflected in the schematization: Within the 165 ft (» 50 m) wide rectangular channel, the discharge is located 20 m from the left bank. The roughness of the slightly winding, but otherwise clean natural channel has been specified by a Manning's n value of 0.03.

Figure C.4 is the data checklist prepared for the CORMIX1 session, while Table C.1 represents the detailed CORMIX1 Prediction File (the session report is not given here). CORMIX1 predicts that the plume gets rapidly mixed over theshallow depth, and is primarily influenced by farfield mixing processes, a feature that is quite consistent with observations. The dye concentration distribution predicted by CORMIX1 in the schematic rectangular channel are plotted in Figure C.5 and show a much more regular mixing pattern than the earlier Figure C.3. However, matters can be readily reconciled when both field data and CORMIX1 predictions are interpreted as a function of cumulative discharge (for example by means of the far-field post-processor FFLOCATR, although the details of the FFLOCATR application are not shown herein).

This has been done in Figure C.6 where both distributions are directly superposed on the cumulative discharge pattern. The agreement is excellent. This entire procedure points out the need for high-quality field data if detailed interpretations and predictions of discharge plumes are desired.

C.3 Proposed Multiport Diffuser Discharge Under 7Q10 flow Conditions: CORMIX2 Predictions

The following strategy is pursued in order111 Table C.1 CORMIX1 Prediction File for dye test in Shallow River

CORMIX1 PREDICTION FILE: 11111111111111111111111111111111111111111111111111111111111111111111111111111 CORNELL MIXING ZONE EXPERT SYSTEM Subsystem CORMIX1: Subsystem version: Submerged Single Port Discharges CORMIX_v.3.10__________June_1995

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- CASE DESCRIPTION Site name/label: Shallow^River Design case: Dye^Test FILE NAME: cormix\sim\dye1 .cx1 Time of Fortran run: 04/14/96--11:03:24

ENVIRONMENT PARAMETERS (metric units) Bounded section BS = 50.00 AS = 30.00 QA = 23.70 ICHREG= 2 HA = .60 HD = .60 UA = .790 F = .084 USTAR = .8081E-01 UW = 2.000 UWSTAR= .2198E-02 Uniform density environment STRCND= U RHOAM = 998.2051

DISCHARGE PARAMETERS (metric units) BANK = LEFT DISTB = 20.00 D0 = .200 A0 = .031 H0 = .15 THETA = .00 SIGMA = .00 U0 = 2.929 Q0 = .092 = .9200E-01 RHO0 = 997.7714 DRHO0 = .4337E+00 GP0 = .4260E-02 C0 = .5600E+03 CUNITS= ppb IPOLL = 1 KS = .0000E+00 KD = .0000E+00

FLUX VARIABLES (metric units) Q0 = .9200E-01 M0 = .2694E+00 J0 = .3920E-03 SIGNJ0= 1.0 Associated length scales (meters) LQ = .18 LM = 18.89 Lm = .66 Lb = .00 Lmp = 99999.00 Lbp = 99999.00

NON-DIMENSIONAL PARAMETERS FR0 = 100.31 R = 3.70

FLOW CLASSIFICATION 111111111111111111111111111111111111111111 1 Flow class (CORMIX1) = H5-0 1 1 Applicable layer depth HS = .60 1 111111111111111111111111111111111111111111

MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS C0 = .5600E+03 CUNITS= ppb NTOX = 0 NSTD = 0 REGMZ = 0 XINT = 1000.00 XMAX = 1000.00

X-Y-Z COORDINATE SYSTEM: ORIGIN is located at the bottom and below the center of the port: 20.00 m from the LEFT bank/shore. X-axis points downstream, Y-axis points to left, Z-axis points upward. NSTEP = 20 display intervals per module

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD101: DISCHARGE MODULE

COANDA ATTACHMENT immediately following the discharge.

X Y Z S C B .00 .00 .00 1.0 .560E+03 .14

END OF MOD101: DISCHARGE MODULE

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN CORJET (MOD110): JET/PLUME NEAR-FIELD MIXING REGION

Bottom-attached jet motion.112 Profile definitions: B = Gaussian 1/e (37%) half-width, normal to trajectory Half wall jet, attached to bottom. S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any)

X Y Z S C B .00 .00 .00 1.0 .560E+03 .10 1.05 .00 .00 1.2 .483E+03 .16 2.10 .00 .00 1.7 .337E+03 .21 3.15 .00 .00 2.1 .263E+03 .26 4.21 .00 .00 2.6 .216E+03 .29 5.26 .00 .00 3.0 .185E+03 .32 6.31 .00 .00 3.4 .163E+03 .35 7.36 .00 .00 3.8 .146E+03 .38 8.41 .00 .00 4.2 .132E+03 .40 9.46 .00 .00 4.6 .121E+03 .42 10.51 .00 .00 5.0 .112E+03 .44 11.56 .00 .00 5.3 .105E+03 .46 12.62 .00 .00 5.7 .983E+02 .48 13.67 .00 .00 6.0 .927E+02 .50 14.72 .00 .00 6.4 .878E+02 .51 15.77 .00 .00 6.7 .834E+02 .53 16.82 .00 .00 7.0 .795E+02 .55 17.87 .00 .00 7.4 .761E+02 .56 18.92 .00 .00 7.7 .729E+02 .57 19.97 .00 .00 8.0 .701E+02 .59 21.03 .00 .00 8.3 .675E+02 .60 Cumulative travel time = 14. sec

END OF CORJET (MOD110): JET/PLUME NEAR-FIELD MIXING REGION

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD133: LAYER BOUNDARY IMPINGEMENT/FULL VERTICAL MIXING

Control volume inflow: X Y Z S C B 21.03 .00 .00 8.3 .675E+02 .60

Profile definitions: BV = layer depth (vertically mixed) BH = top-hat half-width, in horizontal plane normal to trajectory ZU = upper plume boundary (Z-coordinate) ZL = lower plume boundary (Z-coordinate) S = hydrodynamic average (bulk) dilution C = average (bulk) concentration (includes reaction effects, if any)

X Y Z S C BV BH ZU ZL 20.43 .00 .60 8.3 .675E+02 .00 .00 .60 .60 20.55 .00 .60 8.3 .675E+02 .60 .11 .60 .00 20.67 .00 .60 8.3 .675E+02 .60 .15 .60 .00 20.79 .00 .60 8.3 .675E+02 .60 .19 .60 .00 20.91 .00 .60 8.3 .675E+02 .60 .22 .60 .00 21.03 .00 .60 8.3 .675E+02 .60 .24 .60 .00 21.15 .00 .60 8.8 .637E+02 .60 .27 .60 .00 21.27 .00 .60 9.9 .568E+02 .60 .29 .60 .00 21.39 .00 .60 10.8 .517E+02 .60 .31 .60 .00 21.51 .00 .60 11.4 .493E+02 .60 .33 .60 .00 21.63 .00 .60 11.6 .482E+02 .60 .35 .60 .00 Cumulative travel time = 15. sec

END OF MOD133: LAYER BOUNDARY IMPINGEMENT/FULL VERTICAL MIXING

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD153: VERTICALLY MIXED PLUME IN CO-FLOW

Phase 1: Vertically mixed, Phase 2: Re-stratified

Phase 1: The plume is VERTICALLY FULLY MIXED over the entire layer depth. This flow region is INSIGNIFICANT in spatial extent and will be by-passed.

----------------------------------------------------------------------------- Phase 2: The flow has RESTRATIFIED at the beginning of this zone.

This flow region is INSIGNIFICANT in spatial extent and will be by-passed.113 END OF MOD153: VERTICALLY MIXED PLUME IN CO-FLOW

----------------------------------------------------------------------------- ** End of NEAR-FIELD REGION (NFR) **

The initial plume WIDTH values in the next far-field module will be CORRECTED by a factor 3.25 to conserve the mass flux in the far-field! The correction factor is quite large because of the small ambient velocity relative to the strong mixing characteristics of the discharge! This indicates localized RECIRCULATION REGIONS and internal hydraulic JUMPS. Flow appears highly UNSTEADY and prediction results are UNRELIABLE!

----------------------------------------------------------------------------- BEGIN MOD141: BUOYANT AMBIENT SPREADING

Discharge is non-buoyant or weakly buoyant. Therefore BUOYANT SPREADING REGIME is ABSENT.

END OF MOD141: BUOYANT AMBIENT SPREADING

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD161: PASSIVE AMBIENT MIXING IN UNIFORM AMBIENT

Vertical diffusivity (initial value) = .970E-02 m^2/s Horizontal diffusivity (initial value) = .242E-01 m^2/s

The passive diffusion plume is VERTICALLY FULLY MIXED at beginning of region.

Profile definitions: BV = Gaussian s.d.*sqrt(pi/2) (46%) thickness, measured vertically = or equal to layer depth, if fully mixed BH = Gaussian s.d.*sqrt(pi/2) (46%) half-width, measured horizontally in Y-direction ZU = upper plume boundary (Z-coordinate) ZL = lower plume boundary (Z-coordinate) S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any)

Plume Stage 1 (not bank attached): X Y Z S C BV BH ZU ZL 21.63 .00 .60 11.6 .482E+02 .60 1.12 .60 .00 70.55 .00 .60 25.3 .222E+02 .60 2.44 .60 .00 119.47 .00 .60 33.8 .166E+02 .60 3.26 .60 .00 168.39 .00 .60 40.5 .138E+02 .60 3.92 .60 .00 217.30 .00 .60 46.3 .121E+02 .60 4.48 .60 .00 266.22 .00 .60 51.5 .109E+02 .60 4.98 .60 .00 315.14 .00 .60 56.1 .998E+01 .60 5.43 .60 .00 364.06 .00 .60 60.5 .926E+01 .60 5.84 .60 .00 412.98 .00 .60 64.5 .869E+01 .60 6.23 .60 .00 461.90 .00 .60 68.3 .820E+01 .60 6.60 .60 .00 510.81 .00 .60 71.9 .779E+01 .60 6.95 .60 .00 559.73 .00 .60 75.3 .744E+01 .60 7.28 .60 .00 608.65 .00 .60 78.5 .713E+01 .60 7.59 .60 .00 657.57 .00 .60 81.7 .686E+01 .60 7.90 .60 .00 706.49 .00 .60 84.7 .661E+01 .60 8.19 .60 .00 755.41 .00 .60 87.6 .639E+01 .60 8.47 .60 .00 804.33 .00 .60 90.4 .619E+01 .60 8.74 .60 .00 853.24 .00 .60 93.2 .601E+01 .60 9.01 .60 .00 902.16 .00 .60 95.8 .584E+01 .60 9.27 .60 .00 951.08 .00 .60 98.4 .569E+01 .60 9.52 .60 .00 1000.00 .00 .60 101.0 .555E+01 .60 9.76 .60 .00 Cumulative travel time = 1249. sec

Simulation limit based on maximum specified distance = 1000.00 m. This is the REGION OF INTEREST limitation.

END OF MOD161: PASSIVE AMBIENT MIXING IN UNIFORM AMBIENT

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- CORMIX1: Submerged Single Port Discharges End of Prediction File 11111111111111111111111111111111111111111111111111111111111111111111111111111

### 114 Figure C.5: Dye concentrations predicted by CORMIX1 plotted as a function of distance from right bank in schematized channel

Figure C.6: Comparison of measured field dye distribution and CORMIX1 predictions within cumulative discharge pattern115 to improve the near-field mixing characteristics of Furthermore, a high initial dilution of 29.8 is the existing discharge: (1) Utilization of a multiport attai ned in a short region (labeled the diffuser to increase the initial entrainment of "acceleration zone", MOD271) following the high ambient water into the multiple effluent jets, and velocity multiport discharge. These results are (2) shifting of the discharge location toward the plotted in Figure C.8 using the graphics package right bank to delay the contact with the left CMXG RAPH. In order to illustrate the capabilities shoreline that -with the present installation- of the graphics program these plots include (a) seems to occur at a downstream distance of 1000 the un-scaled plan view as it first appears on ft. screen, (b) a re-scaled plan view that is

The design study is carried out for the low narrow plume shape and river stretch, and (c) a flow ambient condition given by the 7Q10 side view of the near-field only with 1:2 vertical discharge (285 cfs  8.1 m /s) as is typical for distortion. The user should explore the manifold 3 water quality studies on riverine sites. features of the graphics package. Temperatures of the discharge and ambient and channel roughness is assumed unc hanged. The Obviously, predicted plan plume shapes new local and average depth for this flowrate is calculated to be  0.3 m from the formula given in Section 4.3.1.

State water quality regulations call for a demonstration of plume concentrations at the edge of a mixing zone that is limited to one fourth (1/4) of the river width. With an average river width of 250 ft, this corresponds to a width limitation of 250/4  62 ft (  19 m). (Note: The actual width limitation must be handled within the schematized cross-sections as specified. For the schematic channel width of 50 m this represents a 19/50 = 38% width limitation specification as used in CORIMX2.)

Obviously, a number of design solutions, with different diffuser configurations and locations, need to be investigated. One of several feasible solutions is presented in the following: A 15 m (  49 ft) long diffuser consisting of 7 nozzles is installed in perpendicular, co-flowing arrangement centered at the 40% cumulative discharge position. (Note: In the actual coordinate position, this corresponds to a distance of about 70 ft from the right bank; see Figure C.1.) The nozzle diameter is 2.5 in (  0.0635 m).

The CORMIX2 simulation is summarized in Figure C.7 (data preparation checklist), Table C.2 (session report), and Table C.3 (prediction file).

Inspection of the session record and prediction file shows that the plume becomes rapidly mixed over the very shallow water depth. undistorted (1:1) to show the actual long and

should be interpreted with the cumulative discharge method . The far-field plume locator FFLOCATR (Section 6.2) is designed for exactly that purpose. The two data files examples in Section 6.2 (input: Table 6.4, output: Table 6.5) are, in fact, applications for the present design case. Hence, the results of Table 6.5 when plotted on the river plan view with the cumulative discharge isolines are shown in Figure C.9 and exhibit realistic plume shapes. After the rapid initial mixing in the near-field the plume is growing only very slowly in the far-field (MOD261). At the 1000 ft transect, the plume stays clear of the left bank.

The concentration distribution along the plume centerline is plotted in Figure C.10 for the near-field only, as very slow additional mixing occurs at larger distances (see Table C.3). As regards the regulatory mixing zone (RMZ) the prediction results indicate that it will be encountered at a considerable distance downstream, at about 354 m (  1200 ft), i.e. outside the region plotted in Figure C.10. The dilution at that location is 33.5, corresponding to a local centerline concentration value of 3.0 %.

Finally, it is illuminating to compare the performance of the proposed multiport diffuser design with the existing single port situation, both under 7Q10 low flow. This is also incl uded in Figure C.10 by plotting the plume centerline concentrations. (Note: The data sheet, session record, and output file for this CORMIX1 application are omitted for space reasons.) Clearly, the multiport design achieves much more116 rapid initial mixing by capturing more of the single plume out of the 7-nozzle arrangement to ambient entrainment flow as the diffuser is spread provide more detail in the near-field; the user has over portion of the river width. Figure C.10 also been prompted by several messages within includes an additional CORMIX1 prediction for a CORMIX2 to perform this additional prediction.120 Table C.3 CORMIX2 Prediction File for B-Plant discharge into Shallow River with multiport diffuser

CORMIX2 PREDICTION FILE: 22222222222222222222222222222222222222222222222222222222222222222222222222222 CORNELL MIXING ZONE EXPERT SYSTEM Subsystem CORMIX2: Subsystem version: Submerged Multiport Diffuser Discharges CORMIX_v.3.00__________July_1994

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- CASE DESCRIPTION Site name/label: B-PLANT^SHALLOW-RIVER Design case: LOW-FLOW^7Q10 FILE NAME: cormix\sim\SAMPLE2 .cx2 Time of Fortran run: 06/24/95--22:36:15

ENVIRONMENT PARAMETERS (metric units) Bounded section BS = 50.00 AS = 15.00 QA = 8.10 ICHREG= 2 HA = .30 HD = .30 UA = .540 F = .105 USTAR = .6199E-01 UW = 2.000 UWSTAR= .2198E-02 Uniform density environment STRCND= U RHOAM = 998.2051

DIFFUSER DISCHARGE PARAMETERS (metric units) Diffuser type: DITYPE= unidirectional_perpendicular BANK = RIGHT DISTB = 20.00 YB1 = 12.50 YB2 = 27.50 LD = 15.00 NOPEN = 7 SPAC = 2.50 D0 = .064 A0 = .003 H0 = .09 Nozzle/port arrangement: unidirectional_without_fanning GAMMA = 90.00 THETA = .00 SIGMA = .00 BETA = 90.00 U0 = 4.150 Q0 = .092 = .9200E-01 RHO0 = 997.7714 DRHO0 = .4337E+00 GP0 = .4260E-02 C0 = .1000E+03 CUNITS= PERCENT IPOLL = 1 KS = .0000E+00 KD = .0000E+00

FLUX VARIABLES - PER UNIT DIFFUSER LENGTH (metric units) q0 = .6133E-02 m0 = .2545E-01 j0 = .2613E-04 SIGNJ0= 1.0 Associated 2-d length scales (meters) lQ=B = .001 lM = 28.81 lm = .09 lmp = 99999.00 lbp = 99999.00 la = 99999.00

FLUX VARIABLES - ENTIRE DIFFUSER (metric units) Q0 = .9200E-01 M0 = .3818E+00 J0 = .3920E-03 Associated 3-d length scales (meters) LQ = .15 LM = 24.53 Lm = 1.14 Lb = .00 Lmp = 99999.00 Lbp = 99999.00

NON-DIMENSIONAL PARAMETERS FR0 = 1653.66 FRD0 = 252.28 R = 7.68 (slot) (port/nozzle)

FLOW CLASSIFICATION 222222222222222222222222222222222222222222 2 Flow class (CORMIX2) = MU2 2 2 Applicable layer depth HS = .30 2 222222222222222222222222222222222222222222

MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS C0 = .1000E+03 CUNITS= PERCENT NTOX = 0 NSTD = 0 REGMZ = 1 REGSPC= 2 XREG = .00 WREG = 19.00 AREG = .00 XINT = 1000.00 XMAX = 1000.00

X-Y-Z COORDINATE SYSTEM: ORIGIN is located at the bottom and the diffuser mid-point: 20.00 m from the RIGHT bank/shore. X-axis points downstream, Y-axis points to left, Z-axis points upward. NSTEP = 20 display intervals per module

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD201: DIFFUSER DISCHARGE MODULE121 Due to complex near-field motions: EQUIVALENT SLOT DIFFUSER (2-D) GEOMETRY

Profile definitions: BV = Gaussian 1/e (37%) half-width, in vertical plane normal to trajectory BH = top-hat half-width, in horizontal plane normal to trajectory S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any)

X Y Z S C BV BH .00 .00 .09 1.0 .100E+03 .00 7.50

END OF MOD201: DIFFUSER DISCHARGE MODULE

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD271: ACCELERATION ZONE OF UNIDIRECTIONAL CO-FLOWING DIFFUSER

In this laterally contracting zone the diffuser plume becomes VERTICALLY FULLY MIXED over the entire layer depth (HS = .30m). Full mixing is achieved after a plume distance of about five layer depths from the diffuser.

Profile definitions: BV = layer depth (vertically mixed) BH = top-hat half-width, in horizontal plane normal to trajectory S = hydrodynamic average (bulk) dilution C = average (bulk) concentration (includes reaction effects, if any)

X Y Z S C BV BH .00 .00 .09 1.0 .100E+03 .00 7.50 .38 .00 .09 11.2 .894E+01 .08 7.39 .75 .00 .10 15.4 .649E+01 .15 7.30 1.13 .00 .10 18.6 .536E+01 .23 7.22 1.50 .00 .10 21.4 .468E+01 .30 7.15 1.88 .00 .11 23.8 .420E+01 .30 7.09 2.25 .00 .11 26.0 .385E+01 .30 7.04 2.63 .00 .11 28.0 .358E+01 .30 6.99 3.00 .00 .11 29.8 .335E+01 .30 6.95 3.38 .00 .12 29.8 .335E+01 .30 6.91 3.75 .00 .12 29.8 .335E+01 .30 6.87 4.13 .00 .12 29.8 .335E+01 .30 6.84 4.50 .00 .13 29.8 .335E+01 .30 6.82 4.88 .00 .13 29.8 .335E+01 .30 6.80 5.25 .00 .13 29.8 .335E+01 .30 6.78 5.63 .00 .14 29.8 .335E+01 .30 6.76 6.00 .00 .14 29.8 .335E+01 .30 6.75 6.38 .00 .14 29.8 .335E+01 .30 6.74 6.75 .00 .14 29.8 .335E+01 .30 6.74 7.13 .00 .15 29.8 .335E+01 .30 6.74 7.50 .00 .15 29.8 .335E+01 .30 6.73 Cumulative travel time = 11. sec

END OF MOD271: ACCELERATION ZONE OF UNIDIRECTIONAL CO-FLOWING DIFFUSER

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD251: DIFFUSER PLUME IN CO-FLOW

Phase 1: Vertically mixed, Phase 2: Re-stratified

Phase 1: The diffuser plume is VERTICALLY FULLY MIXED over the entire layer depth. This flow region is INSIGNIFICANT in spatial extent and will be by-passed.

----------------------------------------------------------------------------- Phase 2: The flow has RESTRATIFIED at the beginning of this zone.

This flow region is INSIGNIFICANT in spatial extent and will be by-passed.

END OF MOD251: DIFFUSER PLUME IN CO-FLOW

----------------------------------------------------------------------------- ** End of NEAR-FIELD REGION (NFR) **

The initial plume WIDTH values in the next far-field module will be CORRECTED by a factor 1.24 to conserve the mass flux in the far-field!

----------------------------------------------------------------------------- BEGIN MOD241: BUOYANT AMBIENT SPREADING

Discharge is non-buoyant or weakly buoyant. Therefore BUOYANT SPREADING REGIME is ABSENT.122 END OF MOD241: BUOYANT AMBIENT SPREADING

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD261: PASSIVE AMBIENT MIXING IN UNIFORM AMBIENT

Vertical diffusivity (initial value) = .372E-02 m^2/s Horizontal diffusivity (initial value) = .930E-02 m^2/s

The passive diffusion plume is VERTICALLY FULLY MIXED at beginning of region.

Profile definitions: BV = Gaussian s.d.*sqrt(pi/2) (46%) thickness, measured vertically = or equal to layer depth, if fully mixed BH = Gaussian s.d.*sqrt(pi/2) (46%) half-width, measured horizontally in Y-direction ZU = upper plume boundary (Z-coordinate) ZL = lower plume boundary (Z-coordinate) S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any)

Plume Stage 1 (not bank attached): X Y Z S C BV BH ZU ZL 7.50 .00 .30 29.8 .335E+01 .30 8.37 .30 .00 57.13 .00 .30 30.4 .329E+01 .30 8.53 .30 .00 106.75 .00 .30 30.9 .323E+01 .30 8.68 .30 .00 156.38 .00 .30 31.5 .318E+01 .30 8.83 .30 .00 206.00 .00 .30 32.0 .313E+01 .30 8.98 .30 .00 255.63 .00 .30 32.5 .308E+01 .30 9.13 .30 .00 305.25 .00 .30 33.0 .303E+01 .30 9.27 .30 .00 354.88 .00 .30 33.5 .298E+01 .30 9.42 .30 .00 ** REGULATORY MIXING ZONE BOUNDARY ** In this prediction interval the TOTAL plume width meets or exceeds the regulatory value = 19.00 m. This is the extent of the REGULATORY MIXING ZONE. 404.50 .00 .30 34.0 .294E+01 .30 9.56 .30 .00 454.13 .00 .30 34.5 .290E+01 .30 9.69 .30 .00 503.75 .00 .30 35.0 .286E+01 .30 9.83 .30 .00 553.38 .00 .30 35.5 .282E+01 .30 9.96 .30 .00 603.00 .00 .30 36.0 .278E+01 .30 10.10 .30 .00 652.63 .00 .30 36.4 .275E+01 .30 10.23 .30 .00 702.25 .00 .30 36.9 .271E+01 .30 10.36 .30 .00 751.88 .00 .30 37.3 .268E+01 .30 10.48 .30 .00 801.50 .00 .30 37.8 .265E+01 .30 10.61 .30 .00 851.13 .00 .30 38.2 .262E+01 .30 10.73 .30 .00 900.75 .00 .30 38.7 .259E+01 .30 10.86 .30 .00 950.38 .00 .30 39.1 .256E+01 .30 10.98 .30 .00 1000.00 .00 .30 39.5 .253E+01 .30 11.10 .30 .00 Cumulative travel time = 1828. sec

Simulation limit based on maximum specified distance = 1000.00 m. This is the REGION OF INTEREST limitation.

END OF MOD261: PASSIVE AMBIENT MIXING IN UNIFORM AMBIENT

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- Because of the fairly LARGE SPACING between adjacent risers/nozzles/ports, the above results may be unreliable in the immediate near-field of the diffuser. A SUBSEQUENT APPLICATION OF CORMIX1 IS RECOMMENDED to provide more detail for one of the individual jets/plumes in the initial region before merging.

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- CORMIX2: Submerged Multiport Diffuser Discharges End of Prediction File 22222222222222222222222222222222222222222222222222222222222222222222222222222

### 123 Figure C.8: CORMIX2 prediction for B-Plant multiport diffuser discharge in Shallow River. Examples of different graphics plots: a) Plan view over entire reach, b) equivalent undistorted plan view, and c) side view of near-field only.

### 124 Figure C.9: Results of cumulative discharge interpretation of CORMIX2 prediction for B-Plant multiport diffuser discharge in Shallow River

Figure C.10: Predicted plume centerline concentrations for multiport diffuser design (CORMIX1) in comparison to single port design (CORMIX2)125 

## Appendix D CORMIX3: Buoyant Surface Discharge In An Estuary

Estuarine conditions are characterized by surface discharge plume for this situation will be highly variable ambient conditions during the tidal quite variable in appearance and mixing cycle. This case study provides a short characteristics due to the tidal reversal, a steady application example for a buoyant surface state simulation will be performed to illustrate the discharge from a large manufacturing plant basic CORMIX3 application in a time invariant discharging its process water into an estuary. ambient receiving water. Furthermore, this

D.1 Problem Statement

A manufacturing plant (C-Plant) is using process water at a capacity of 2.2 m /s (  50 3 mgd). The process water is essentially fresh water with a discharge temperature of 20.0 C o and contains copper at a concentration of 80 μg/l.

The plant is located at the shore of an estuary. Figure D.1 shows the bottom bathymetry at the plant location; two transects have been measured and show a relatively rapid drop-off from the MSL line to a depth of about 5 m below MSL. It is proposed to build a discharge c hannel with a bottom elevation of about 1.0 m below MSL and a width of 2.0 m. Thus, given the tidal variation at the discharge location indicated in Figure D.1, the actual channel depth will vary from a maximum of about 1.8 m at MHW to a minimum of about 0.5 at MLW, with corresponding adjustments in the discharge velocity.

Figure D.2 shows data from oceanographic field surveys near the discharge site with ambient velocity variations from about +0.7 m/s for flood tide and to about -0.7 m/s for ebb tide. Figure D.2 also shows the tidal elevation variations from -.7 m above MLW at ebb to +1.1 m above MLW at flood. The estuary has brackish water with mean salinity of about 26 ppt, yielding a density of about 1018 kg/m (see Figure 3 4.3 as an aid).

State regulations specify a mixing z one of about 250 m extending in any direction from the discharge point. The CMC and CCC values for copper are 25 and 15 μg/l, respectively.

D.2 Steady State Simulation (for reference)

Although it is to be expected that the simulation will be used as a basis for comparison in the next selection, where tidal CORMIX simulations are appropriately performed in order to determine the time evolution in this highly unsteady environment.

Assume that the conditions one hour after low water slack tide (t = 11.7 h) represent that in a large steady river (see condition (b), Figure D.2). This design condition is represented by a water level 0.35 m below MSL and an ambient velocity of 0.22 m/s. As shown in Figure D.1, the ambient water body is schematized as unbounded, with an average depth of 6 m at MSL, a local depth of 2.5 m at MSL (1.5 m below the discharge channel mouth), and a bottom sl ope of 11°.

Figure D.3 presents the input data checklist and Table D.1 shows the CORMIX3 prediction file (the session report is omitted here for brevity) for the steady state reference condition one hour after low water slack (LWS). The shallow discharge channel (depth of 0.65 m) produces a relatively weak free jet (flow class FJ1). After only 4.5 m offshore distance, the initial jet momentum is overwhelmed by the high discharge buoyancy, and forms a surface plume which is weakly deflected by the ambient crossflow (MOD313). In this region, buoyant forces rapidly thin and spread the plume horizontally. Both the CCC and CMC are met within this region, (and also within the regulatory mixing zone) as is displayed by CORMIX in the prediction file. The plume then becomes str ongly deflected (MOD323) and finally contacts the shoreline some 1560 m downstream. The plume then becomes attached to the shoreline, and spreads through passive ambient diffusion and weak buoyant forces (MOD341), until the end of the region of interest (2000 m). Figure D.4 shows the above behavior.

### 126 Figure D.1: Bathymetric conditions in Estuary in vicinity of C-Plant surface discharge

Figure D.2: Oceanographic data for Estuary showing tidal elevation and current. A complete tidal analysis might include simulations for all time instances labeled a to g.128 Table D.1 CORMIX3 Prediction Steady-Sate Prediction File for Surface Buoyant Discharge

CORMIX3 PREDICTION FILE: 33333333333333333333333333333333333333333333333333333333333333333333333333333 CORNELL MIXING ZONE EXPERT SYSTEM Subsystem CORMIX3: Subsystem version: Buoyant Surface Discharges CORMIX_v.3.10__________June_1995

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- CASE DESCRIPTION Site name/label: C-PLANT^ESTUARY Design case: STEADY^SIMULATION^ONE^HOUR^AFTER^SLACK FILE NAME: cormix\sim\SAMPLE3 .cx3 Time of Fortran run: 06/24/95--22:32:20

ENVIRONMENT PARAMETERS (metric units) Unbounded section HA = 5.65 HD = 5.65 UA = .220 F = .025 USTAR = .1230E-01 UW = 2.000 UWSTAR= .2198E-02 Uniform density environment STRCND= U RHOAM = 1018.0000

DISCHARGE PARAMETERS (metric units) BANK = RIGHT DISTB = .00 Configuration: flush_discharge SIGMA = 90.00 HD0 = 2.15 SLOPE = 11.00 Rectangular channel geometry: B0 = 2.000 H0 = .650 A0 = .1300E+01 AR = .325 U0 = 1.692 Q0 = 2.200 = .2200E+01 RHO0 = 998.2051 DRHO0 = .1979E+02 GP0 = .1907E+00 C0 = .8000E+02 CUNITS= MUG-P-L IPOLL = 1 KS = .0000E+00 KD = .0000E+00

FLUX VARIABLES (metric units) Q0 = .2200E+01 M0 = .3723E+01 J0 = .4195E+00 Associated length scales (meters) LQ = 1.14 LM = 4.14 Lm = 8.77 Lb = 39.40

NON-DIMENSIONAL PARAMETERS FR0 = 3.62 FRCH = 4.80 R = 7.69

FLOW CLASSIFICATION 333333333333333333333333333333333333333333 3 Flow class (CORMIX3) = FJ1 3 3 Applicable layer depth HS = 5.65 3 333333333333333333333333333333333333333333

MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS C0 = .8000E+02 CUNITS= MUG-P-L NTOX = 1 CMC = .2500E+02 CCC = CSTD NSTD = 1 CSTD = .1500E+02 REGMZ = 1 REGSPC= 1 XREG = 250.00 WREG = .00 AREG = .00 XINT = 2000.00 XMAX = 2000.00

X-Y-Z COORDINATE SYSTEM: ORIGIN is located at the WATER SURFACE and at center of discharge channel/outlet: .00 m from the RIGHT bank/shore. X-axis points downstream Y-axis points to left as seen by an observer looking downstream Z-axis points vertically upward (in CORMIX3, all values Z = 0.00) NSTEP = 20 display intervals per module

----------------------------------------------------------------------------- TRJBUO TRJATT TRJBND TRJNBY TRJCOR DILCOR C 3.401 1.000 1.000 1.000 3.400 1.000

----------------------------------------------------------------------------- BEGIN MOD301: DISCHARGE MODULE

Efflux conditions: X Y Z S C BV BH .00 .00 0.00 1.0 .800E+02 .65 1.00

END OF MOD301: DISCHARGE MODULE129 -----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD302: ZONE OF FLOW ESTABLISHMENT

Control volume inflow: X Y Z S C BV BH .00 .00 0.00 1.0 .800E+02 .65 1.00

Profile definitions: BV = Gaussian 1/e (37%) vertical thickness BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any)

Control volume outflow: X Y Z S C BV BH .13 4.11 0.00 1.4 .576E+02 1.09 1.41 Cumulative travel time = 2. sec

END OF MOD302: ZONE OF FLOW ESTABLISHMENT

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD311: WEAKLY DEFLECTED JET (3-D)

Surface JET into a crossflow

Profile definitions: BV = Gaussian 1/e (37%) vertical thickness BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any)

X Y Z S C BV BH .13 4.11 0.00 1.4 .576E+02 1.28 1.65 .13 4.14 0.00 1.4 .575E+02 1.28 1.66 .13 4.16 0.00 1.4 .574E+02 1.28 1.66 .13 4.18 0.00 1.4 .573E+02 1.28 1.66 .13 4.20 0.00 1.4 .572E+02 1.29 1.66 .14 4.23 0.00 1.4 .571E+02 1.29 1.67 .14 4.25 0.00 1.4 .570E+02 1.29 1.67 .14 4.27 0.00 1.4 .569E+02 1.29 1.67 .14 4.29 0.00 1.4 .568E+02 1.30 1.67 .15 4.32 0.00 1.4 .567E+02 1.30 1.68 .15 4.34 0.00 1.4 .566E+02 1.30 1.68 .15 4.36 0.00 1.4 .565E+02 1.30 1.68 .15 4.38 0.00 1.4 .564E+02 1.30 1.68 .15 4.41 0.00 1.4 .563E+02 1.31 1.69 .16 4.43 0.00 1.4 .562E+02 1.31 1.69 .16 4.45 0.00 1.4 .561E+02 1.31 1.69 .16 4.47 0.00 1.4 .560E+02 1.31 1.69 .16 4.50 0.00 1.4 .559E+02 1.32 1.70 .17 4.52 0.00 1.4 .558E+02 1.32 1.70 .17 4.54 0.00 1.4 .558E+02 1.32 1.70 .17 4.56 0.00 1.4 .557E+02 1.32 1.70 Cumulative travel time = 3. sec

END OF MOD311: WEAKLY DEFLECTED JET (3-D)

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD313: WEAKLY DEFLECTED PLUME

Surface PLUME into a crossflow

Profile definitions: BV = Gaussian 1/e (37%) vertical thickness BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any)

X Y Z S C BV BH .17 4.56 0.00 1.4 .557E+02 1.32 1.70 .41 6.86 0.00 2.3 .343E+02 .82 4.48 .67 9.16 0.00 2.9 .279E+02 .66 6.76 ** CMC HAS BEEN FOUND ** The pollutant concentration in the plume falls below CMC value of .250E+02 in the current prediction interval. This is the extent of the TOXIC DILUTION ZONE.130 .96 11.46 0.00 3.3 .244E+02 .58 8.88 1.28 13.76 0.00 3.6 .220E+02 .52 10.93 1.62 16.05 0.00 4.0 .202E+02 .48 12.95 1.99 18.35 0.00 4.3 .188E+02 .45 14.94 2.38 20.65 0.00 4.5 .177E+02 .42 16.93 2.80 22.95 0.00 4.8 .167E+02 .40 18.92 3.25 25.25 0.00 5.0 .159E+02 .38 20.91 3.72 27.54 0.00 5.3 .152E+02 .36 22.90 ** WATER QUALITY STANDARD OR CCC HAS BEEN FOUND ** The pollutant concentration in the plume falls below water quality standard or CCC value of .150E+02 in the current prediction interval. This is the spatial extent of concentrations exceeding the water quality standard or CCC value. 4.22 29.84 0.00 5.5 .146E+02 .35 24.90 4.75 32.14 0.00 5.7 .140E+02 .33 26.92 5.30 34.44 0.00 5.9 .135E+02 .32 28.93 5.87 36.74 0.00 6.1 .131E+02 .31 30.96 6.48 39.03 0.00 6.3 .126E+02 .30 33.00 7.11 41.33 0.00 6.5 .123E+02 .29 35.05 7.76 43.63 0.00 6.7 .119E+02 .28 37.11 8.44 45.93 0.00 6.9 .116E+02 .28 39.18 9.15 48.23 0.00 7.1 .113E+02 .27 41.25 9.88 50.52 0.00 7.2 .110E+02 .26 43.34 Cumulative travel time = 248. sec

END OF MOD313: WEAKLY DEFLECTED PLUME

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD323: STRONGLY DEFLECTED PLUME

Profile definitions: BV = top-hat thickness,measured vertically BH = top-hat half-width, measured horizontally in Y-direction S = hydrodynamic average (bulk) dilution C = average (bulk) concentration (includes reaction effects, if any)

X Y Z S C BV BH 9.88 50.52 0.00 7.2 .110E+02 .26 43.34 84.15 123.86 0.00 7.5 .107E+02 .23 60.96 158.42 154.39 0.00 7.8 .103E+02 .22 77.07 232.69 176.11 0.00 8.1 .985E+01 .22 92.39 ** REGULATORY MIXING ZONE BOUNDARY ** In this prediction interval the plume distance meets or exceeds the regulatory value = 250.00 m. This is the extent of the REGULATORY MIXING ZONE. 306.96 193.50 0.00 8.6 .934E+01 .22 107.24 381.23 208.23 0.00 9.1 .876E+01 .23 121.77 455.50 221.14 0.00 9.8 .815E+01 .25 136.02 529.77 232.70 0.00 10.7 .750E+01 .26 150.02 604.04 243.21 0.00 11.7 .685E+01 .28 163.77 678.31 252.88 0.00 12.9 .621E+01 .30 177.26 752.58 261.87 0.00 14.3 .560E+01 .32 190.49 826.84 270.29 0.00 15.9 .504E+01 .34 203.46 901.11 278.21 0.00 17.7 .452E+01 .36 216.17 975.38 285.70 0.00 19.7 .406E+01 .39 228.65 1049.65 292.82 0.00 21.9 .365E+01 .41 240.91 1123.92 299.61 0.00 24.4 .328E+01 .44 252.95 1198.18 306.11 0.00 27.1 .295E+01 .47 264.79 1272.45 312.34 0.00 30.0 .267E+01 .50 276.45 1346.72 318.34 0.00 33.1 .241E+01 .54 287.93 1420.99 324.11 0.00 36.5 .219E+01 .57 299.25 1495.25 329.69 0.00 40.1 .199E+01 .61 310.43 Cumulative travel time = 7000. sec

END OF MOD323: STRONGLY DEFLECTED PLUME

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- ** End of NEAR-FIELD REGION (NFR) **

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD341: BUOYANT AMBIENT SPREADING

Profile definitions: BV = top-hat thickness,measured vertically BH = top-hat half-width, measured horizontally from bank/shoreline S = hydrodynamic average (bulk) dilution C = average (bulk) concentration (includes reaction effects, if any)131 Plume Stage 1 (not bank attached): X Y Z S C BV BH 1495.25 329.69 0.00 40.1 .199E+01 .63 319.79 1498.55 329.69 0.00 40.3 .199E+01 .63 320.29 1501.84 329.69 0.00 40.5 .198E+01 .63 320.79 1505.13 329.69 0.00 40.6 .197E+01 .63 321.29 1508.42 329.69 0.00 40.8 .196E+01 .63 321.79 1511.72 329.69 0.00 41.0 .195E+01 .64 322.29 1515.01 329.69 0.00 41.1 .195E+01 .64 322.78 1518.30 329.69 0.00 41.3 .194E+01 .64 323.28 1521.59 329.69 0.00 41.5 .193E+01 .64 323.78 1524.89 329.69 0.00 41.6 .192E+01 .64 324.27 1528.18 329.69 0.00 41.8 .191E+01 .64 324.77 1531.47 329.69 0.00 42.0 .191E+01 .65 325.27 1534.77 329.69 0.00 42.1 .190E+01 .65 325.76 1538.06 329.69 0.00 42.3 .189E+01 .65 326.26 1541.35 329.69 0.00 42.5 .188E+01 .65 326.75 1544.64 329.69 0.00 42.6 .188E+01 .65 327.25 1547.94 329.69 0.00 42.8 .187E+01 .65 327.74 1551.23 329.69 0.00 43.0 .186E+01 .65 328.23 1554.52 329.69 0.00 43.2 .185E+01 .66 328.73 1557.81 329.69 0.00 43.3 .185E+01 .66 329.22 1561.11 329.69 0.00 43.5 .184E+01 .66 329.71 Cumulative travel time = 7299. sec

----------------------------------------------------------------------------- Plume is ATTACHED to RIGHT bank/shore. Plume width is now determined from RIGHT bank/shore.

Plume Stage 2 (bank attached): X Y Z S C BV BH 1561.11 .00 0.00 43.5 .184E+01 .66 659.39 1583.05 .00 0.00 44.6 .179E+01 .67 662.33 1605.00 .00 0.00 45.7 .175E+01 .69 665.27 1626.94 .00 0.00 46.8 .171E+01 .70 668.21 1648.89 .00 0.00 48.0 .167E+01 .71 671.16 1670.83 .00 0.00 49.1 .163E+01 .73 674.11 1692.78 .00 0.00 50.3 .159E+01 .74 677.06 1714.72 .00 0.00 51.4 .156E+01 .76 680.01 1736.66 .00 0.00 52.6 .152E+01 .77 682.97 1758.61 .00 0.00 53.8 .149E+01 .78 685.92 1780.55 .00 0.00 55.0 .146E+01 .80 688.88 1802.50 .00 0.00 56.2 .142E+01 .81 691.83 1824.44 .00 0.00 57.4 .139E+01 .83 694.79 1846.39 .00 0.00 58.6 .136E+01 .84 697.75 1868.33 .00 0.00 59.9 .134E+01 .85 700.71 1890.28 .00 0.00 61.1 .131E+01 .87 703.67 1912.22 .00 0.00 62.4 .128E+01 .88 706.62 1934.17 .00 0.00 63.6 .126E+01 .90 709.58 1956.11 .00 0.00 64.9 .123E+01 .91 712.54 1978.05 .00 0.00 66.2 .121E+01 .93 715.50 2000.00 .00 0.00 67.5 .118E+01 .94 718.46 Cumulative travel time = 9294. sec

Simulation limit based on maximum specified distance = 2000.00 m. This is the REGION OF INTEREST limitation.

END OF MOD341: BUOYANT AMBIENT SPREADING

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- CORMIX3: Buoyant Surface Discharges End of Prediction File 33333333333333333333333333333333333333333333333333333333333333333333333333333

### 132 Figure D.4: CORMIX3 prediction of surface discharge from C-Plant into Estuary using a steady-state simulation. a) Plume shape in near- and far-field, and b) concentration along plume centerline.133 D.3 Detailed Tidal Simulations

A high variation in both ambient velocity and tidal elevation occurs during the tidal episode shown in Figure D.2. The changing water height produces a discharge velocity which varies from 0.61 m/s (at high water slack) to 2.2 m/s (at low water slack). When combined with the large buoyancy flux, this pr oduces flows which change from momentum dominated jets to highly buoyant plumes in a short period of time. Simultaneously, the time-variant ambient velocity (which ranges from stagnant to 0.75 m/s) produces flows which are free and unattached at slack tide, yet become strongly shore- hugging at maximum flood or ebb currents.

In such highly time-variant ambient conditions, it is recommended that several CORMIX predictions be performed at critical tidal conditions throughout a reversal episode. These critical tidal conditions are identified as: 1) Shortly after slack tide: Effects of reentrainment of discharge from the previous half-cycle are greatest. However, the flow is evolving rapidly in time, causing CORMIX tidal predictions to be limited in spatial extent. Several predictions should be made at hourly or half hourly intervals following the reversal. 2) Maximum flood and ebb currents : These represent extremes of along-shoreextent and shoreline interaction. Reentrainment will be less important at these times. For the present scenario, it is suggested that up to seven simulations be performed at the times indicated on Figure D.2 by the letters a-g. In the following section, a detailed simulation is performed corresponding to time b, one hour after slack tide. The results are contrasted for that case to the steady-state assumption simulated in the preceding.

D.4 Tidal simulation one hour after slack tide

A detailed example of the tidal simulation capability of CORMIX is presented in this section, using conditions corresponding to those in Section D.2 (see Figure D.2, time b). To perform a CORMIX tidal simulation, four additional pieces of data are required: 1) the tidal period (usually 12.4 hours for a semi-diurnal tidal cycle) 2) the time of simulation (in hours relative to slack tide) 3) the ambient velocity at the time of simulation 4) the maximum velocity which occurs during the tidal cycle From this data, CORMIX calculates the rate of reversal (du /dt) and related unsteady length a scales (L , T , [ L ] , see Table 5.4), and u u m min determines the spatial extent of CORMIX applicability and the re-entrainment and build-up caused by the reversal of ambient current. (Note: If a simulation is performed at slack tide, then the time of simulation is t = 0 h, and the ambient velocity is set to u = 0 m/s.) However, in order to a calculate the reversal rate, CORMIX requires input of the ambient velocity at an other time near reversal (for example, at one hour before or after slack tide). This information is only used to determine the limit of spatial applicability for the slack tide simulation.

For this application, the time of simulation is one hour after slack tide. The ambient velocity at this time is u = 0.22 m/s, and the ambient and a discharge channel depths are the same as in Section D.2. The maximum ambient velocity during the tidal cycle is 0.75 m/s. For this simulation, the data preparation checklist is given in Figure D.5.

Table D.2 lists the CORMIX session report and Table D.3 the CORMIX3 prediction file for this tidal application. Two important consequences are evident when comparing Table D.3 and Table D.1 (corresponding steady-state simulation): 1) a concentration build-up in the near-field, and 2) the termination of the plume prediction after some distance. The latter distance is the region over which a reasonably steady-state plume can establish itself within the time-varying tidal environment. The theoretical background for these procedures is given in the report on recent CORMIX enhancements (8).137 Table D.3 CORMIX3 Prediction File for C-Plant discharge into Estuary with unsteady tidal conditions

CORMIX3 PREDICTION FILE: 33333333333333333333333333333333333333333333333333333333333333333333333333333 CORNELL MIXING ZONE EXPERT SYSTEM Subsystem CORMIX3: Subsystem version: Buoyant Surface Discharges CORMIX_v.3.10__________June_1995

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- CASE DESCRIPTION Site name/label: C-PLANT^ESTUARY Design case: TIDAL^SIMULATION^ONE^HOUR^AFTER^SLACK FILE NAME: cormix\sim\SAMPLE3T.cx3 Time of Fortran run: 06/24/95--22:34:03

ENVIRONMENT PARAMETERS (metric units) Unbounded section HA = 5.65 HD = 5.65 Tidal Simulation at TIME = 1.000 h PERIOD= 12.40 h UAmax = .750 dUa/dt= .220 (m/s)/h UA = .220 F = .025 USTAR = .1230E-01 UW = 2.000 UWSTAR= .2198E-02 Uniform density environment STRCND= U RHOAM = 1018.0000

DISCHARGE PARAMETERS (metric units) BANK = RIGHT DISTB = .00 Configuration: flush_discharge SIGMA = 90.00 HD0 = 2.15 SLOPE = 11.00 Rectangular channel geometry: B0 = 2.000 H0 = .650 A0 = .1300E+01 AR = .325 U0 = 1.692 Q0 = 2.200 = .2200E+01 RHO0 = 998.2051 DRHO0 = .1979E+02 GP0 = .1907E+00 C0 = .8000E+02 CUNITS= MUG-P-L IPOLL = 1 KS = .0000E+00 KD = .0000E+00

FLUX VARIABLES (metric units) Q0 = .2200E+01 M0 = .3723E+01 J0 = .4195E+00 Associated length scales (meters) LQ = 1.14 LM = 4.14 Lm = 8.77 Lb = 39.40 Tidal: Tu = .2229 h Lu = 39.347 Lmin = 2.573

NON-DIMENSIONAL PARAMETERS FR0 = 3.62 FRCH = 4.80 R = 7.69

FLOW CLASSIFICATION 333333333333333333333333333333333333333333 3 Flow class (CORMIX3) = FJ1 3 3 Applicable layer depth HS = 5.65 3 333333333333333333333333333333333333333333

MIXING ZONE / TOXIC DILUTION / REGION OF INTEREST PARAMETERS C0 = .8000E+02 CUNITS= MUG-P-L NTOX = 1 CMC = .2500E+02 CCC = CSTD NSTD = 1 CSTD = .1500E+02 REGMZ = 1 REGSPC= 1 XREG = 250.00 WREG = .00 AREG = .00 XINT = 2500.00 XMAX = 3500.00

X-Y-Z COORDINATE SYSTEM: ORIGIN is located at the WATER SURFACE and at center of discharge channel/outlet: .00 m from the RIGHT bank/shore. X-axis points downstream Y-axis points to left as seen by an observer looking downstream Z-axis points vertically upward (in CORMIX3, all values Z = 0.00) NSTEP = 20 display intervals per module

----------------------------------------------------------------------------- TRJBUO TRJATT TRJBND TRJNBY TRJCOR DILCOR C 3.401 1.000 1.000 1.000 3.400 1.000

----------------------------------------------------------------------------- BEGIN MOD301: DISCHARGE MODULE

Efflux conditions: X Y Z S C BV BH .00 .00 0.00 1.0 .800E+02 .65 1.00138 END OF MOD301: DISCHARGE MODULE

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD302: ZONE OF FLOW ESTABLISHMENT

Control volume inflow: X Y Z S C BV BH .00 .00 0.00 1.0 .800E+02 .65 1.00

Profile definitions: BV = Gaussian 1/e (37%) vertical thickness BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any)

Control volume outflow: X Y Z S C BV BH .13 4.11 0.00 1.4 .586E+02 1.09 1.41 Cumulative travel time = 2. sec

END OF MOD302: ZONE OF FLOW ESTABLISHMENT

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD311: WEAKLY DEFLECTED JET (3-D)

Surface JET into a crossflow

Profile definitions: BV = Gaussian 1/e (37%) vertical thickness BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any)

X Y Z S C BV BH .13 4.11 0.00 1.4 .586E+02 1.28 1.65 .13 4.14 0.00 1.4 .585E+02 1.28 1.66 .13 4.16 0.00 1.4 .584E+02 1.28 1.66 .13 4.18 0.00 1.4 .583E+02 1.28 1.66 .13 4.20 0.00 1.4 .582E+02 1.29 1.66 .14 4.23 0.00 1.4 .581E+02 1.29 1.67 .14 4.25 0.00 1.4 .580E+02 1.29 1.67 .14 4.27 0.00 1.4 .580E+02 1.29 1.67 .14 4.29 0.00 1.4 .579E+02 1.30 1.67 .15 4.32 0.00 1.4 .578E+02 1.30 1.68 .15 4.34 0.00 1.4 .577E+02 1.30 1.68 .15 4.36 0.00 1.4 .576E+02 1.30 1.68 .15 4.38 0.00 1.4 .575E+02 1.30 1.68 .15 4.41 0.00 1.4 .574E+02 1.31 1.69 .16 4.43 0.00 1.4 .573E+02 1.31 1.69 .16 4.45 0.00 1.4 .572E+02 1.31 1.69 .16 4.47 0.00 1.4 .571E+02 1.31 1.69 .16 4.50 0.00 1.4 .571E+02 1.32 1.70 .17 4.52 0.00 1.4 .570E+02 1.32 1.70 .17 4.54 0.00 1.4 .569E+02 1.32 1.70 .17 4.56 0.00 1.4 .568E+02 1.32 1.70 Cumulative travel time = 3. sec

END OF MOD311: WEAKLY DEFLECTED JET (3-D)

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD313: WEAKLY DEFLECTED PLUME

Surface PLUME into a crossflow

Profile definitions: BV = Gaussian 1/e (37%) vertical thickness BH = Gaussian 1/e (37%) horizontal half-width, normal to trajectory S = hydrodynamic centerline dilution C = centerline concentration (includes reaction effects, if any)

X Y Z S C BV BH .17 4.56 0.00 1.4 .568E+02 1.32 1.70 .41 6.86 0.00 2.3 .354E+02 .82 4.48 .67 9.16 0.00 2.8 .291E+02 .66 6.76 .96 11.46 0.00 3.1 .256E+02 .58 8.88 ** CMC HAS BEEN FOUND ** The pollutant concentration in the plume falls below CMC value of .250E+02139 in the current prediction interval. This is the extent of the TOXIC DILUTION ZONE. 1.28 13.76 0.00 3.4 .233E+02 .52 10.93 1.62 16.05 0.00 3.7 .216E+02 .48 12.95 1.99 18.35 0.00 3.9 .203E+02 .45 14.94 2.38 20.65 0.00 4.2 .192E+02 .42 16.93 2.80 22.95 0.00 4.4 .184E+02 .40 18.92 3.25 25.25 0.00 4.5 .176E+02 .38 20.91 3.72 27.54 0.00 4.7 .170E+02 .36 22.90 4.22 29.84 0.00 4.9 .164E+02 .35 24.90 4.75 32.14 0.00 5.0 .159E+02 .33 26.92 5.30 34.44 0.00 5.2 .155E+02 .32 28.93 5.87 36.74 0.00 5.3 .151E+02 .31 30.96 ** WATER QUALITY STANDARD OR CCC HAS BEEN FOUND ** The pollutant concentration in the plume falls below water quality standard or CCC value of .150E+02 in the current prediction interval. This is the spatial extent of concentrations exceeding the water quality standard or CCC value. 6.48 39.03 0.00 5.4 .147E+02 .30 33.00 7.11 41.33 0.00 5.6 .144E+02 .29 35.05 7.76 43.63 0.00 5.7 .141E+02 .28 37.11 8.44 45.93 0.00 5.8 .138E+02 .28 39.18 9.15 48.23 0.00 5.9 .136E+02 .27 41.25 9.88 50.52 0.00 6.0 .134E+02 .26 43.34 Cumulative travel time = 248. sec

END OF MOD313: WEAKLY DEFLECTED PLUME

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- BEGIN MOD323: STRONGLY DEFLECTED PLUME

Profile definitions: BV = top-hat thickness,measured vertically BH = top-hat half-width, measured horizontally in Y-direction S = hydrodynamic average (bulk) dilution C = average (bulk) concentration (includes reaction effects, if any)

X Y Z S C BV BH 9.88 50.52 0.00 6.0 .134E+02 .26 43.34 84.15 123.86 0.00 4.9 .163E+02 .23 60.96 158.42 154.39 0.00 4.6 .174E+02 .22 77.07 232.69 176.11 0.00 4.5 .178E+02 .22 92.39 ** REGULATORY MIXING ZONE BOUNDARY ** In this prediction interval the plume distance meets or exceeds the regulatory value = 250.00 m. This is the extent of the REGULATORY MIXING ZONE. 282.05 187.67 0.00 4.5 .177E+02 .22 102.26 Cumulative travel time = 1485. sec

CORMIX prediction has been TERMINATED at last prediction interval. Limiting distance due to TIDAL REVERSAL has been reached.

END OF MOD323: STRONGLY DEFLECTED PLUME

-----------------------------------------------------------------------------

----------------------------------------------------------------------------- CORMIX3: Buoyant Surface Discharges End of Prediction File 33333333333333333333333333333333333333333333333333333333333333333333333333333

The results of the tidal simulations are at the edge of the RMZ (compare Figure D.4b and shown graphically in Figure D.6. The most D.6b at a distance of 250 m downstream) in the obvious difference in the tidal CORMIX prediction tidal application as a result of tidal re-entrainment. at this time is that the maximum predicted As a result, the copper concentration at the RMZ downstream distance is limited to 275 m in the x- is 18 μg/L as opposed to 10 μg/L for the steady direction. Furthermore, a significant increase in state simulation, which exceeds the CCC at this the pollutant concentration (copper) is observed distance.

### 140 Figure D.6: CORMIX3 prediction of surface discharge from C-Plant into Estuary using a unsteady tidal simulation. a) Plume shape in near-field only (prediction is terminated after this region), and b) concentration along plume centerline.141 

## Appendix E Two Applications of CORJET

Two case studies are presented here in the same direction, i.e. along the coastline. illustrating the application of the post-processing The water depth at the discharge location is of the model included within CORMIX, namely CORJET, order of 30 m. the Cornell buoyant jet integral model. As discussed in Section 6.1 is an important tool for The CORJET data preparation checklist predicting additional details within the near-field of for this design case is given as Figure E.1. a submerged discharge. Both case studies are Density data is specified in this case via included in the normal CORMIX installation temperature and salinity. The program computes package. internally the actual density distribution using the

It is repeated here that CORJET, as any noted that in case of multiple ambient levels jet integral model, if used alone and by an CORJET assumes outside the specified range inexperienced analyst, is not a safe methodology for mixing zone analysis . It is advised to use it only in conjunction with the more comprehensive CORMIX system. Therefore, in case of engineering design applications, CORJET should be employed after prior use of the expert system CORMIX has indicated that the buoyant jet will not experience any instabilities due to shallow water or due to attachment to boundaries

.

E.1 Submerged multiport diffuser in deep water
A short diffuser consisting of 11 ports and a total length of 20 m is discharging fresh water at a temperature of 30 C into the stratified coastal o ocean. The diffuser ports are each 0.5 m in diameter and well-rounded in their internal hydraulic design so that no further exit flow contraction will occur. The nozzles are oriented with a vertical angle of 45 upward and a o horizontal angle of 45 pointing into the ambient o crossflow (see multiport diffuser definition diagram, Figures 4.6 and 4.7). The diffuser has an alignment of 60 with respect to the ambient o current. The discharge flow has a concentration of 100 % of some conservative substance.

Detailed measurements in the water column give the distribution of temperature, salinity and current velocity as a function of vertical distance. The current at each level flows full (UNESCO) equation of state. It should be

(e.g. above 15 m in this case) that the data are linearly contin ued from the last specified interval. If uniform ambient conditions exist only a single level must be specified.

The port height H0 in the input data specification is set to 0.0 m; thus, the coordinate system is conveniently set at the discharge height. Another value for the actual height above the water bottom could be used too, but remember that CORJET, as all integral models, does not compute actual bottom interaction effects (see Section 6.1.1). A maximum computation height of 30 m and distance of 200 m is specified to stop the computation. The number of print intervals is set to 10, in order to provide sufficient detail.

A prior application of CORMIX (using a linear density approximation Type A) has shown that a stable multiport diffuser flow class MS results for this case. The reader is encouraged to ascertain that! Thus, CORJET is indeed applicable for this case.

Table E.1 shows the input data file as prepared externally using a line editor. The CORJET prediction file is shown in Table E.2. The file echoes the input data, but also lists the computed density values, and all important parameters and non-dimensional numbers. Note that all parameters and scales are referenced to the values of ambient conditions at the level of discharge . The second half of the output table gives the predicted plume conditions.143 Table E.1 CORJET input data file for multiport diffuser discharge into stratified coastal waters
#CORJET INPUT FILE #Title line (50 characters max.): Case5: MULTIPORT DIFFUSER: STRATIFIED, VARIABLE CURRENT #Fluid (1=water,2=air), Density option (1=calculate,2=specify directly): #Fluid (1⁄2): Density option (1⁄2): Ambient levels (1-10): 1 1 3 #Ambient conditions (if d.o.=1, fill in TA+SA; if 2, fill in RHOA): #Level ZA TA SA RHOA UA TAUA 1 0. 12. 30. 0.5 0. 2 5. 15. 29.5 0.8 0. 3 15. 20. 28. 1.2 0. #Discharge conditions (T0+S0, or RHO0 as above; if NOPEN=1: set LD=0,ALIGN=0): #NOPEN D0 H0 U0 THETA0 SIGMA0 C0 KD T0 S0 RHO0 LD ALIGN 11 0.5 0. 3.0 45. 45. 100. 0. 30. 0. 20. 60. #Program control: #ZMAX ZMIN DISMAX NPRINT 30. 0. 200. 10

Table E.2 CORJET prediction file for multiport diffuser discharge into stratified coastal waters

CORJET PREDICTION FILE: JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ CORJET: CORNELL BUOYANT JET INTEGRAL MODEL Version 4.1, April 1996

---------------------------------------------------------------------------- FILE NAME: post\cj\case5mpd.OUT Label/identifier: Case5: MULTIPORT DIFFUSER: STRATIFIED, VARIABLE CU Time of CORJET run: 4/13/96--15:56:58

Ambient conditions: No. of levels: 3 Fluid: Water Density option: 1 LEV ZA TA SA RHOA UA TAUA 1 .00 12.00 30.00 1022.71 .50 .00 2 5.00 15.00 29.50 1021.74 .80 .00 3 15.00 20.00 28.00 1019.43 1.20 .00

Discharge conditions (metric): For each port: D0 H0 U0 THETA0 SIGMA0 C0 KD T0 S0 RHO0 .500 .00 3.00 45.00 45.00 .10E+03 .00E+0 30.0 .0 995.65 MULTIPORT DIFFUSER conditions: NOPEN LD SPAC ALIGN Q0total 11 20.00 2.00 60.00 6.480 = .6480E+01

Program control: ZMAX ZMIN DISMAX NPRINT 30.00 .00 200.00 10

Flux variables (based on ambient at discharge level): For each port: Q0 = .589E+00 M0 = .177E+01 J0 = .153E+00 GP0 = .259E+00 QT0 = .106E+02 QS0 = -.177E+02 For multiport diffuser (per unit length): q0 = .324E+00 m0 = .972E+00 j0 = .841E-01

Length scales (m) and parameters: For each port: LQ = .44 LM = 3.92 Lm = 2.66 Lb = 1.22 Lmp = 5.61 Lbp = 6.71 For multiport diffuser (per unit length): lQ=B = .108 lM = 5.07 lm = 3.89 lq* = .74 lmp = 8.16 lbp = 10.37 FR0 = 8.33 FR02 = 17.92 Fa = 1.14 R = 6.00 (port) (2-D slot) Zone of flow establishment (m): LE = 1.30 XE = .75 YE = .62 ZE = .86 THETAE= 38.34 SIGMAE= 34.00 GAMMAE= 49.43

---------------------------------------------------------------------------- CORJET PREDICTION: Stepsize = .2659 Printout every 10 steps Individual jet/plumes before merging: X Y Z Sc Cc B | DIST Save Gpc dTc dSALc .00 .00 .00 1.0 .100E+03 .25| .00 1.0 .26E+00 18.0-30.0 .75 .62 .86 1.0 .100E+03 .25| 1.30 1.4 .27E+00 20.8-34.7 2.80 1.50 2.27 3.0 .333E+02 .64| 3.96 4.6 .83E-01 5.2 -9.9 Merging of individual jet/plumes to form plane jet/plume:144 Horizontal jet/plume half-width BH = B + 10.00 4.26 1.78 2.85 4.5 .223E+02 .82| 5.55 6.6 .54E-01 3.1 -6.5 5.31 1.84 3.01 6.3 .159E+02 .90| 6.62 6.4 .38E-01 2.1 -4.7 7.96 1.88 3.22 7.4 .136E+02 1.09| 9.27 7.5 .32E-01 1.6 -3.9 10.61 1.89 3.41 8.4 .118E+02 1.27| 11.93 8.6 .28E-01 1.3 -3.4 13.26 1.89 3.59 9.5 .105E+02 1.45| 14.59 9.7 .24E-01 1.1 -3.0 15.91 1.89 3.77 10.6 .940E+01 1.63| 17.25 10.7 .21E-01 .8 -2.7 18.57 1.89 3.94 11.7 .852E+01 1.81| 19.91 11.8 .19E-01 .6 -2.4 21.22 1.89 4.11 12.8 .779E+01 1.99| 22.57 12.9 .17E-01 .5 -2.2 23.88 1.89 4.27 13.9 .717E+01 2.17| 25.23 14.0 .15E-01 .3 -2.0 26.53 1.89 4.43 15.1 .664E+01 2.34| 27.89 15.1 .14E-01 .2 -1.8 29.18 1.89 4.58 16.2 .619E+01 2.51| 30.54 16.1 .13E-01 .1 -1.7 31.84 1.89 4.73 17.2 .580E+01 2.68| 33.20 17.2 .12E-01 .0 -1.6 34.49 1.89 4.87 18.3 .545E+01 2.85| 35.86 18.2 .11E-01 -.1 -1.5 37.15 1.89 5.01 19.4 .515E+01 3.02| 38.52 19.3 .97E-02 -.2 -1.4 39.80 1.89 5.15 20.5 .488E+01 3.18| 41.18 20.3 .89E-02 -.2 -1.3 42.46 1.89 5.28 21.5 .464E+01 3.34| 43.84 21.4 .82E-02 -.3 -1.2 45.11 1.89 5.41 22.6 .443E+01 3.49| 46.50 22.4 .75E-02 -.3 -1.1 47.77 1.89 5.53 23.6 .424E+01 3.64| 49.15 23.4 .69E-02 -.4 -1.0 50.43 1.89 5.65 24.6 .407E+01 3.79| 51.81 24.3 .63E-02 -.4 -1.0 53.08 1.89 5.77 25.6 .391E+01 3.94| 54.47 25.3 .58E-02 -.5 -.9 55.74 1.89 5.88 26.5 .377E+01 4.08| 57.13 26.2 .54E-02 -.5 -.9 58.39 1.89 5.99 27.5 .364E+01 4.22| 59.79 27.1 .49E-02 -.6 -.8 61.05 1.89 6.09 28.4 .352E+01 4.35| 62.45 28.0 .45E-02 -.6 -.8 63.71 1.89 6.20 29.3 .342E+01 4.48| 65.11 28.9 .42E-02 -.6 -.7 66.36 1.89 6.29 30.1 .332E+01 4.61| 67.77 29.7 .38E-02 -.7 -.7 69.02 1.89 6.39 31.0 .323E+01 4.73| 70.42 30.5 .35E-02 -.7 -.7 71.68 1.89 6.48 31.8 .315E+01 4.85| 73.08 31.3 .32E-02 -.7 -.6 74.34 1.89 6.57 32.6 .307E+01 4.96| 75.74 32.1 .29E-02 -.8 -.6 76.99 1.89 6.65 33.3 .300E+01 5.07| 78.40 32.8 .27E-02 -.8 -.6 79.65 1.89 6.74 34.1 .293E+01 5.17| 81.06 33.5 .24E-02 -.8 -.6 82.31 1.89 6.81 34.8 .287E+01 5.27| 83.72 34.2 .22E-02 -.9 -.5 84.97 1.89 6.89 35.5 .282E+01 5.37| 86.38 34.9 .20E-02 -.9 -.5 87.62 1.89 6.96 36.1 .277E+01 5.46| 89.03 35.5 .18E-02 -.9 -.5 90.28 1.89 7.03 36.7 .272E+01 5.54| 91.69 36.1 .16E-02 -.9 -.5 92.94 1.89 7.09 37.3 .268E+01 5.62| 94.35 36.6 .14E-02 -.9 -.5 95.60 1.89 7.16 37.8 .264E+01 5.70| 97.01 37.1 .12E-02 -1.0 -.4 98.26 1.89 7.22 38.3 .261E+01 5.77| 99.67 37.6 .11E-02 -1.0 -.4 100.91 1.89 7.27 38.8 .258E+01 5.83| 102.33 38.1 .93E-03 -1.0 -.4 103.57 1.89 7.33 39.2 .255E+01 5.89| 104.99 38.5 .80E-03 -1.0 -.4 106.23 1.89 7.38 39.6 .252E+01 5.95| 107.65 38.9 .67E-03 -1.0 -.4 108.89 1.89 7.43 40.0 .250E+01 6.00| 110.30 39.2 .56E-03 -1.1 -.4 111.55 1.89 7.47 40.3 .248E+01 6.04| 112.96 39.5 .45E-03 -1.1 -.4 114.20 1.89 7.51 40.6 .246E+01 6.08| 115.62 39.8 .35E-03 -1.1 -.4 116.86 1.89 7.55 40.8 .245E+01 6.11| 118.28 40.0 .26E-03 -1.1 -.3 119.52 1.89 7.59 41.0 .244E+01 6.13| 120.94 40.2 .17E-03 -1.1 -.3 122.18 1.89 7.62 41.1 .243E+01 6.15| 123.60 40.3 .94E-04 -1.1 -.3 124.84 1.89 7.65 41.2 .243E+01 6.16| 126.26 40.3 .23E-04 -1.1 -.3 125.90 1.89 7.66 41.2 .243E+01 6.15| 127.32 40.3 -.35E-05 -1.1 -.3 Terminal level in stratified ambient has been reached. PROGRAM STOPS!

---------------------------------------------------------------------------- END OF CORJET PREDICTION: Total number of integration steps = 475 JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ Note: CORJET has been used outside the CORMIX system, assuming unlimited receiving water. Carefully examine all results for possible boundary effects due to surface, bottom, or lateral boundaries!145 The CORJET program when called within discharge has a diameter of 3 m and an exit the normal CORMIX installation after its execution velocity of 10 m/s. A discharge concentration of automatically links to the graphics package 100 % exists for a fairly rapidly decaying CMXGRAPH so the user can inspect the substance with a decay rate of 1 per 10 min or predicted plume, rather than looking at the output 0. 0028 /s. file. Many graphics options (see Section 5.3) exist to fully evaluate the plume geometry and Typical measurements, for example using concentration distributions. Three examples of a tracked rising balloon, give the distribution of graphics output are shown in Figures E.2 and E.3. temperature and wind velocity as a function of

Figure E.2 shows the plan view, side view, CORJET data preparation checklist given as and side view along the trajectory, respectively, of Figure E.4. Density data is specified in this case the plume, all with a plot scale fixed to 1:1, i.e. as air temperature, the program will convert undistorted. All these figures have been density i nputs internally to potential density as a produced with the Postscript-file print option (I) of function of temperature. The wind velocity vector CMXGRAPH (in contrast to all the figures in with increasing height deviates increasingly from Appendices B to D that were made with the the direction at ground level. In this example the screen print (C) option). Such an undistorted is coordinate system has been set at ground level always preferable for the viewer of such plots in so that the chimney (i.e.“port”) height is equal to order to get an unbiased picture of the mixing 40 m. pattern. Note the merging of the individual jets in the plan view. Figure E.3 gives the concentration Table E.3 shows the input data file for this distribution along the plume centerline trajectory, case, while Table E.4 is the CORJET prediction showing the rapid drop-off in this jet mixing file. The file echoes the input data, but also lists process. the potential density values, and all important

E.2 Smoke plume in stratified atmosphere with skewed wind velocity

As mentioned in Section 6.1 CORJET is also applicable for atmospheric conditions in which case the concept of potential density based on the perfect gas equation with adiabatic conditions is employed. Furthermore, the wind conditions in the lower atmospheric boundary layer with its greater freedom laterally often has a skewed velocity distribution with different wind directions at different levels above the ground. This is the topic of this case study.

An industrial chimney with a height of 40 m above gr ound discharges hot gases at a temperature of 200 C into the atmosphere. The o height above the ground. This is shown in the

parameters and non-dimensional numbers.

Predicted plume properties are shown graphically as Figures E.5 and E.6. Figure E.5 shows the plan view and the side view, respectively, of the plume, both with a plot scale fixed to 1:1, i.e. undistorted. The plan view shows that the plume follows the variable direction of the wind as it rises to higher levels.

Figure E.6 gives the concentration distribution along the plume centerline trajectory. The added effect of plume decay would be discernible only in the detailed output file (Table E.4) where the centerline concentration is not merely the inverse of the hydrodynamic centerline dilution (the effect of pure mixing) but lower because of the internal chemical decay effect.

### 146 Figure E.2: CORJET prediction for multiport diffuser discharge into stratified coastal waters as plotted with graphics package. a) Plan view, b) side view, and c) side view along trajectory both with plot scale fixed at 1:1 (undistorted).

### 147 Figure E.3: CORJET prediction for multiport diffuser discharge into stratified coastal waters as plotted with graphics package. Concentration along centerline trajectory.149 Table E.3 CORJET input data file for chimney discharge into stratified atmosphere with skewed wind

#CORJET INPUT FILE #Title line (50 characters max.): Case3: CHIMNEY, STRATIFIED AIR, VARIABLE WIND #Fluid (1=water,2=air), Density option (1=calculate,2=specify directly): #Fluid (1/2): Density option (1/2): Ambient levels (1-10): 2 1 4 #Ambient conditions (if d.o.=1, fill in TA+SA; if 2, fill in RHOA): #Level ZA TA SA RHOA UA TAUA 1 0. 12.0 2.0 0. 2 50. 12.0 5.0 15. 3 100. 12.5 6.0 25 4 200. 13.0 6.5 30. #Discharge conditions (T0+S0, or RHO0 as above; if NOPEN=1: set LD=0,ALIGN=0): #NOPEN D0 H0 U0 THETA0 SIGMA0 C0 KD T0 S0 RHO0 LD ALIGN 1 3.0 40. 10.0 90. 0. 100. .0028 200. 0. 0. #Program control: #ZMAX ZMIN DISMAX NPRINT 200. 0. 1000. 30

Table E.4 CORJET prediction file for chimney discharge into stratified atmosphere with skewed wind

CORJET PREDICTION FILE: JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ CORJET: CORNELL BUOYANT JET INTEGRAL MODEL Version 4.1, April 1996

---------------------------------------------------------------------------- FILE NAME: post\cj\case3air.OUT Label/identifier: Case3: CHIMNEY, STRATIFIED AIR, VARIABLE WIND Time of CORJET run: 4/13/96--16:12:15

Ambient conditions: No. of levels: 4 Fluid: Air Density option: 1 LEV ZA TA SA RHOA UA TAUA 1 .00 12.00 .00 1.24 2.00 .00 2 50.00 12.00 .00 1.24 5.00 15.00 3 100.00 12.50 .00 1.24 6.00 25.00 4 200.00 13.00 .00 1.23 6.50 30.00

Discharge conditions (metric): SINGLE PORT D0 H0 U0 THETA0 SIGMA0 C0 KD T0 S0 RHO0 3.000 40.00 10.00 90.00 .00 .10E+03 .28E-0 200.0 .0 .75

Program control: ZMAX ZMIN DISMAX NPRINT 200.00 .00 1000.00 30

Flux variables (based on ambient at discharge level): Q0 = .707E+02 M0 = .707E+03 J0 = .275E+03 GP0 = .390E+01 QT0 = .133E+05 QS0 = .000E+00

Length scales (m) and parameters: LQ = 2.66 LM = 8.26 Lm = 6.04 Lb = 3.23 Lmp = 11.97 Lbp = 14.42 FR0 = 2.92 R = 2.27 Zone of flow establishment (m): LE = .00 XE = .00 YE = .00 ZE = 40.00 THETAE= 41.69 SIGMAE= 12.00 GAMMAE= 41.69

---------------------------------------------------------------------------- CORJET PREDICTION: Stepsize = .6042 Printout every 30 steps Single jet/plume: X Y Z Sc Cc B | DIST Save Gpc dTc dSALc .00 .00 40.00 1.0 .100E+03 1.50| .00 1.0 .39E+01188.0 .0 .00 .00 40.00 1.0 .100E+03 1.50| .00 1.4 .41E+01204.4 .0 15.18 3.42 49.21 4.5 .221E+02 3.53| 18.13 6.6 .12E+01 41.6 .0 31.38 7.54 56.20 9.6 .104E+02 5.18| 36.25 13.8 .63E+00 19.5 .0 47.86 12.09 62.22 15.8 .634E+01 6.64| 54.38 22.5 .39E+00 11.8 .0 64.47 16.97 67.60 22.7 .440E+01 7.96| 72.51 32.2 .27E+00 8.1 .0150 81.13 22.13 72.51 30.3 .330E+01 9.18| 90.64 42.8 .20E+00 6.0 .0 97.83 27.54 77.06 38.4 .260E+01 10.30| 108.76 54.0 .16E+00 4.7 .0 114.52 33.18 81.30 47.0 .213E+01 11.36| 126.89 65.8 .13E+00 3.8 .0 131.21 39.03 85.29 55.9 .179E+01 12.35| 145.02 78.1 .11E+00 3.1 .0 147.88 45.08 89.05 65.1 .154E+01 13.29| 163.15 90.7 .90E-01 2.6 .0 164.52 51.31 92.63 74.5 .134E+01 14.18| 181.27 103.7 .77E-01 2.3 .0 181.14 57.72 96.03 84.2 .119E+01 15.02| 199.40 116.9 .67E-01 2.0 .0 197.71 64.29 99.27 94.0 .106E+01 15.83| 217.53 130.4 .58E-01 1.7 .0 214.26 71.02 102.38 103.9 .963E+00 16.60| 235.66 144.1 .52E-01 1.5 .0 230.77 77.88 105.37 113.8 .879E+00 17.35| 253.78 157.8 .47E-01 1.4 .0 247.25 84.85 108.25 123.7 .808E+00 18.06| 271.91 171.7 .42E-01 1.2 .0 263.71 91.92 111.04 133.8 .747E+00 18.75| 290.04 185.6 .39E-01 1.1 .0 280.14 99.07 113.75 143.9 .695E+00 19.42| 308.17 199.6 .35E-01 1.0 .0 296.56 106.30 116.39 154.1 .649E+00 20.07| 326.29 213.7 .32E-01 .9 .0 312.96 113.58 118.96 164.4 .608E+00 20.71| 344.42 228.0 .30E-01 .9 .0 329.34 120.93 121.47 174.7 .572E+00 21.33| 362.55 242.3 .27E-01 .8 .0 345.70 128.34 123.91 185.1 .540E+00 21.93| 380.67 256.7 .25E-01 .7 .0 362.05 135.79 126.30 195.6 .511E+00 22.52| 398.80 271.1 .23E-01 .7 .0 378.39 143.29 128.64 206.1 .485E+00 23.10| 416.93 285.7 .22E-01 .6 .0 394.72 150.83 130.92 216.6 .462E+00 23.66| 435.06 300.2 .20E-01 .6 .0 411.03 158.41 133.16 227.2 .440E+00 24.21| 453.18 314.8 .19E-01 .5 .0 427.33 166.03 135.35 237.8 .421E+00 24.75| 471.31 329.5 .17E-01 .5 .0 443.62 173.69 137.49 248.4 .403E+00 25.28| 489.44 344.1 .16E-01 .5 .0 459.90 181.39 139.58 259.0 .386E+00 25.80| 507.57 358.8 .15E-01 .4 .0 476.17 189.11 141.64 269.6 .371E+00 26.31| 525.69 373.5 .14E-01 .4 .0 492.43 196.87 143.65 280.3 .357E+00 26.80| 543.82 388.1 .13E-01 .4 .0 508.68 204.66 145.62 290.9 .344E+00 27.29| 561.95 402.7 .12E-01 .3 .0 524.92 212.48 147.54 301.4 .332E+00 27.76| 580.08 417.3 .11E-01 .3 .0 541.15 220.33 149.43 312.0 .321E+00 28.23| 598.20 431.9 .10E-01 .3 .0 557.37 228.20 151.28 322.5 .310E+00 28.68| 616.33 446.4 .95E-02 .3 .0 573.58 236.11 153.10 333.0 .300E+00 29.13| 634.46 460.9 .88E-02 .3 .0 589.79 244.03 154.87 343.5 .291E+00 29.57| 652.59 475.2 .81E-02 .2 .0 605.98 251.98 156.61 353.8 .283E+00 30.00| 670.71 489.6 .74E-02 .2 .0 622.17 259.96 158.31 364.2 .275E+00 30.42| 688.84 503.8 .68E-02 .2 .0 638.36 267.96 159.98 374.4 .267E+00 30.83| 706.97 517.9 .63E-02 .2 .0 654.53 275.98 161.61 384.6 .260E+00 31.23| 725.09 532.0 .57E-02 .2 .0 670.69 284.03 163.21 394.8 .253E+00 31.62| 743.22 545.9 .52E-02 .2 .0 686.85 292.09 164.77 404.8 .247E+00 32.01| 761.35 559.7 .47E-02 .1 .0 703.01 300.18 166.30 414.8 .241E+00 32.39| 779.48 573.4 .42E-02 .1 .0 719.15 308.28 167.79 424.6 .235E+00 32.76| 797.60 587.0 .38E-02 .1 .0 735.29 316.41 169.25 434.4 .230E+00 33.12| 815.73 600.4 .34E-02 .1 .0 751.42 324.56 170.68 444.1 .225E+00 33.47| 833.86 613.8 .30E-02 .1 .0 767.54 332.72 172.08 453.6 .220E+00 33.82| 851.99 626.9 .26E-02 .1 .0 783.66 340.90 173.44 463.1 .216E+00 34.16| 870.11 639.9 .22E-02 .1 .0 799.77 349.10 174.77 472.5 .212E+00 34.49| 888.24 652.8 .18E-02 .1 .0 815.88 357.32 176.07 481.7 .208E+00 34.81| 906.37 665.5 .15E-02 .0 .0 831.98 365.55 177.34 490.8 .204E+00 35.13| 924.50 678.0 .12E-02 .0 .0 848.07 373.80 178.57 499.8 .200E+00 35.43| 942.62 690.3 .87E-03 .0 .0 864.16 382.07 179.78 508.6 .197E+00 35.73| 960.75 702.5 .57E-03 .0 .0 880.24 390.35 180.95 517.4 .193E+00 36.03| 978.88 714.5 .29E-03 .0 .0 896.32 398.65 182.09 525.9 .190E+00 36.31| 997.01 726.2 .15E-04 .0 .0 897.39 399.20 182.17 526.5 .190E+00 36.33| 998.21 727.0 -.19E-05 .0 .0 Terminal level in stratified ambient has been reached. PROGRAM STOPS!

---------------------------------------------------------------------------- END OF CORJET PREDICTION: Total number of integration steps = 1653 JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ

### 151 Figure E.5: CORJET prediction for chimney discharge into stratified atmosphere with skewed wind profile as plotted with graphics package. a) Plan view, and b) side view along trajectory both with plot scale fixed at 1:1 (undistorted).

### 152 Figure E.6: CORJET prediction for chimney discharge into stratified atmosphere with skewed wind profile as plotted with graphics package. Concentration along centerline trajectory.