SMS:SRH-2D Model Control

The SRH Model Control dialog showing the General tab.

The SRH Model Control dialog can be reached by using the Model Control command in the SRH-2D menu. From the model control, the user enters data that will be written the files used by SRH for computation.

General Tab

In the General tab, the user will specify the name of the case used for the SRH model. The case name is a keyword that SRH will use to link files together of the same case. A simple word without spaces is needed by the model. The "Simulation Description" is for the user to note information that may be useful to him or her later when reviewing the model. Information entered as the "Simulation Description" are not used the SRH model for computation. Selecting the "Run Type" will communicate to SRH the type of analysis that is to be preformed. The current release of SRH allows only for ‘Flow’ or hydraulic simulations: future versions will allow for morphological and mobile runs which will account for sediment transport simulation. The user may specify whether a run will use Steady or Unsteady output. Using "Steady output" will allow for quicker computation time; whereas, "Unsteady output" requires more time for calculation. The difference lies between the intermediate results. The final results of a Steady or Unsteady analysis will be the same; however, Unsteady allows for accurate intermediate results. From the General tab, the user is able to adjust model run times including a start time, computational time step, and a total simulation time. The default start time is left at zero, but it may need to be adjusted to meet the time specifications of input hydrographs or other data. The time step is used by SRH to make calculations. Depending on the model, the element size, and the input parameters, the time step will need to be adjusted. The "Initial Condition" option communicates to SRH how each cell is to be treated upon launch. SMS leaves the default as dry; suggesting that each element does not have water or is not wet. The user may decide to use a RST file from a previous run on the same mesh as the initial condition for each element or may choose to use the "Automatic" option and leave the initial conditions of each element for SRH to work with.

Flow Tab

Under the Flow tab are the options for the turbulence model used in the simulation. The current release of SRH support the use of the "Parabolic" and "KE turbulence" option. Using "Parabolic" requires the input of constant for the turbulence equation. The default value is left as 0.7. Users should consult the SRH User’s Manual or other reference materials to find the value that is most appropriate for their run.

The SRH Model Control dialog showing the Flow tab.

The SRH Model Control dialog showing the Output tab.

Output Tab

The Output tab has options that will tell SRH what is to be written out as results and how often.

• Result Output Format – specifies the type of file that will be written with results. SRH supports and writes out to the following file formats: XMDF, SRHN, SRHC, and TECPlot formats.
• Result Output Unit – option dictates to SRH the units to be included in the output file whether they be English or International (SI) units.

Related Topics

• SRH-2D