Difference between revisions of "SMS:RMA2 Model Control Dialog"
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:
- 1 General
- 2 Scale Factors
- 3 Timing
- 4 Files
- 5 Global Methods
- 6 Weather
- 7 Related Topics
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
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
- X scale / GS Card
- Y scale / GS Card
- Z scale / GS Card
- 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.
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
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).
See also BV card, TV card.
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
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.
- 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 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
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
- Peclet Number
- Minimum velocity
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
- Specify global wind
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