SMS:RMA2 Model Control Dialog: Difference between revisions

Revision as of 17:30, 17 September 2009

This article highlights frequently used RMA2 model control parameters. Please see the RMA2 model documentation for a description of items not discussed or for more information on specific items.

RMA2 model parameters are divided into the following groups in the RMA2 Model Control:

General

Simulation Titles / $T1 Card

The RMA2 .geo file contains three comment lines, which can be set using the Title 1, Title 2, and Title 3 edit fields.

Machine Type / $M Card

Set the machine type the RMA2 simulation will be run on. Options include:

Microprocessor (PC) - Default option
Prime mini-computer
DEC VAX
Cray or Cyber-205
HP or Alpha workstations

Water Properties

Set the properties of the water being simulated.

Temperature / FT Card
Density / FD Card
Coldstart initial water surface / IC Card
1D node initial conditions
- Minimum depth / IC Card
- Initial velocity / IC Card

Scale Factors

X scale / GS Card
Y scale / GS Card
Z scale / GS Card

Timing

Simulation Type

Steady state - Boundary conditions do not change with time. A "snapshot" in time.
Dynamic - Boundary conditions change with time. Computation Time parameters will need to be specified.

Iterations For Flow Calculations

See the TI Card description in the RMA2 model documentation.

Initial solution - Maximum number of iterations to perform for the initial solution.
Each time step - Used for dynamic simulation - maximum number of iterations to perform after the first time step.

Computation Time

See the TZ Card description in the RMA2 model documentation.

Time step size - DELT Variable
Number of time steps - NCYC Variable
Maximum time - TMAX Variable
First time step - NSTART Variable
Perform intermediate restart - MBAND Variable

Bendway Correction

Used to supply values associated with the calculation of vorticity. See the VO Card description in the RMA2 model documentation.

Compute vorticity - IVOR Variable
ASEC - ASEC coefficient for the vorticity equation. Recommend: 5.0
DSEC - DSEC coefficient for the vorticity equation. Recommend: 0.5
RCMIN - Minimum radius of curvature that will be allowed. Recommend: 6 feet (or 2 meters).

Depth Convergence Parameters

Steady state depth convergence
Dynamic depth convergence

Vorticity Convergence Parameters

See the VO Card description in the RMA2 model documentation.

Steady state vorticity convergence
Dynamic vorticity convergence

Iterations for Vorticity Calculations

The maximum number of iterations allowed for the vorticity calculation is set by tvariables NVITI or NVITN on the TV card. If the number of passes between the phases reaches NPASS1 or NPASS2, then the calculation has failed to converge. If the number of “good passes” between the two phases exceeds NGOODMAX, the calculation is finished and the code can proceed to the next time step. See the "Bendway Correction (Vorticity)" section and TV Card description in the RMA2 model documentation.

The following TV Card variables are used to control the number of iterations for vorticity calculations:

Steady state passes - NPASS1 Variable
Steady state vorticity iterations - NVITI Variable
Dynamic passes - NPASS2 Variable
Dynamic vorticity iterations - NVITN Variable
Number of good passes required - NGOODMAX Variable

Files

RMA2 Input Files

Specify geometry file - select an existing RMA2 ASCII Geometry (*.geo) file to use with the simulation
Hotstart input file - specify an existing RMA2 Hotstart File (*.hot) to use with the simulation
- Use specific time for hotstart
Alternate dynamic BC file - See the "RMA2 Alternate Dynamic BC File Format" section of the RMA2 model documentation
Write dynamic memory file - See the "Dynamic Memory Allocation" section of the RMA2 model documentation

RMA2 Solution Files

Write RMA2 solution file
- Write frequency in timesteps
Write hotstart file - Write an RMA2 Hotstart Output (*.hot) file. See RMA2 Spindown for a discussion of hotstarting.
- Save only the last timestep - Write only the last successful RMA2 timestep solution to the hotstart file.
- Write frequency in timesteps - Write multiple timesteps to the hotstart file.

Informational Files

Echo card input to screen
Write ASCII results file
- Do not echo any node/element input data
- Echo all input data except initial conditions
- Echo all input data
- Write frequency of nodal results in timesteps
- Trace subroutines level
Write summary by node file
Write automatically computed parameters file
Write vorticity file
- Write frequency in timesteps

Global Methods

Global Wet/Dry Technique

See the Material Properties article for a description of the Marsh Porosity parameters.

Elemental wet/dry check
- Check frequency in timesteps
- Dry depth
- Active depth
Nodal Transition (Marsh Porosity)
- Options - Opens the Nodal Transition (Marsh Porosity) dialog

Global Roughness Assignment

Default roughness value
Roughness by depth
- Options - Opens the Roughness Options dialog

Coriolis Forces

Latitude

Global Eddy Viscosity Assignment

See the Material Properties article for a description of the Turbulence parameters.

Traditional eddy viscosity approach (default)
Peclet Number
Smagorinski Method
- Exx ratio
- Eyx ratio
- TBFACTS
- TBMINFS
- Peclet Number
- Minimum velocity

Weather

Wind

According to the RMA2 model documentation, "Because of lack of experience in using storms in a simulation, this feature remains experimental."

See the "Simulating With Storms" section and BWC Card description in the RMA2 model documentation for more information.

Method for wind
- Do not use wind
- Original RMA2 Formula
- Van Dorn Formula
- Wu Formula
- Safaie Formula
- Ekma Formula
- Generic Formula
A
exp
C
rho
Specify global wind
- Define

Rainfall/Evaporation / RA Card

See the "Adding Rainfall And Evaporation" section and RA Card description in the RMA2 model documentation for more information.

Specify rainfall or evaporation
- Define - Opens the Rainfall Values dialog