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 run. The following options are available:

• Simulation Description – 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.
• Case Name – a keyword that SRH will use to link files together of the same case. A simple word without spaces is needed by the model.
• Run Type – communicates to SRH the type of analysis that is to be preformed. Options include the "Flow" option for hydraulic simulations and the "Morphological Analysis" and "Mobile" options for sediment transport simulations.
• Temperature Modeling

• Use temperature modeling

• Unsteady Output – specifies whether a run will use steady or unsteady output. Selecting "On" will specify an unsteady output and selecting "Off" will specify a steady 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.
• Start Time (hours) – the default is left at zero, but it may need to be adjusted to meet the time specifications of input hydrographs or other data.
• Time Step (seconds) 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.
• Total Simulation Time (hours) – determines the total period of time the simulation run will analyze.
• Initial Condition – communicates to SRH how each cell is to be treated upon launch. The following options are available:

• "Dry" – the defualt setting in SMS. This suggests that each element does not have water or is not wet.
• "Initial Water Surface Elevation" – allows changing the Initial Water Surface Elevation for the simulation run. This sets the water surface elevation for all elements to one value. If the elevation at an element is greater than the water surface elevation specified by the user, then the element is dry.
• "Automatic" – assumes backwater from the downstream boundaries with areas above this value assumed dry.
• "Restart File" – activates a Select button which brings up a browser so a user can select an RST file from a previous run on the same mesh as the initial condition for each element. When a simulation is run, SRH-2D will write out a Restart file for each output interval as specified in the Output tab.

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 the following turbulence models:

• Laminar
• Constant
• Parabolic
• KE

Using "Parabolic" requires the input of a 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
• TECPlot

• Result Output Unit – option dictates to SRH the units to be included in the output file whether they be English or International (SI) units.
• Result Output Method – allows the following options:

• Specified Frequency
• Specified Time
• Simulation End

• Result Output Fequency (hours)

Related Topics

• SRH-2D