SMS:CMS-Flow Files

Hot Start File

In the CMS-Flow Model Control, the user can specify a previously saved hot start file to be used as initial conditions or instruct CMS-Flow to save hot start files for future use.

To create a hot start file, either select Write Hot Start output file and select an output time, or select Automatic recurring Hot Start file and choose an output interval.

• Choosing to write the hot start file at a specific output time will create the following file:

• hot_start.h5 This file has the simulation data including elevations and velocities.

• Choosing automatic recurring hot start files will create the following files:

• HOTSTART.INFO This file records what time the hot start file was written and which hot start file is the most recent.
• HOTSTARTx.H5 (where "x" is a counter) These files have the simulation data including elevations and velocities.

Once the hot start files are created, they can be read into CMS-Flow. Open the CMS-Flow Model Control and check the "initial conditions file" check box, then select the hot start file to be used.

When using a hot start file, the following parameters should be changed as follows:

• Start Date: no change
• Start Time: no change
• Simulation Duration: decrease by the duration of the hot start file
• Boundary Conditions: no change

Note: For a simulation using a hot start file, the first time step of the solution will be the start time plus the value of one time step plus the duration of the hot start file.

Storing Save Points in the *.cmcards File

When saving the *.sms project. the save points get stored in the *.cmcards file. An example looks like this:

Save Points

HYDRO_OUTPUT_INTERVAL        5.0 MINUTES 
SEDIMENT_OUTPUT_INTERVAL     5.0 MINUTES 
SALINITY_OUTPUT_INTERVAL     5.0 MINUTES 
WAVE_OUTPUT_INTERVAL         5.0 MINUTES 

The SAVE_POINT is formatted [name][x location][y location][hydro (if on)][sediment (if on)][salinity(if on)][wave(if on)]

SAVE_POINT        "6, 61" -2867.5 2022.0 HYDRO SEDIMENT WAVE
SAVE_POINT        "20, 59" -2517.5 1966.0 HYDRO 
SAVE_POINT        "10, 31" -2767.5 1182.0 SEDIMENT 
SAVE_POINT        "11, 31" -2742.5 1182.0 SEDIMENT 
SAVE_POINT        "10, 32" -2767.5 1210.0 SALINITY 
SAVE_POINT        "11, 32" -2742.5 1210.0 WAVE

Projection Cards

Below are two examples of CMS Flow Projection Cards:

HORIZONTAL_PROJECTION_BEGIN              !Optional 
  DATUM                             NAD83      !NAD27|NAD83|LOCAL 
  SYSTEM                            UTM      !UTM|STATE_PLANE|GEOGRAPHIC|LOCAL 
  UNITS                             METERS      !METERS|FEET|DEGREES 
  ZONE                              15      !Only if necessary 
HORIZONTAL_PROJECTION_END            

VERTICAL_PROJECTION_BEGIN            
  DATUM                             LOCAL      !NGVD29|NAVD88|LOCAL 
  UNITS                             METERS      !METERS|FEET 
  OFFSET                            2.0 m      !Positive is upwards 
VERTICAL_PROJECTION_END

Output Files

Output files specified here are associated with observation cells that have been assigned within the grid. For example, if a time series observation cell exists, an output file will be written out by M2D for every file type that is checked within this dialog. The same holds true for flow rate observation cells. All observation cell output files are given the file extension of “.m2o”. A prefix is specified for all time series and flow rate output files. The user must also specify the time step increment (in seconds) at which to write to the output files. This increment should be a multiple of the simulation time step.

A brief explanation of the information that each of the following observation cell output file types contains is given (* = prefix):

Time Series Output Files:

• U Output (*_u.m2o): Velocity in the x-direction

• V Output (*_v.m2o): Velocity in the y-direction

• ETA Output (*_h.m2o): Water level

• U DETA/DX (u /x) (*_udhdx.m2o):

• V DETA/DY (v /y) (*_vdhdy.m2o):

• ETA DU/DX (u/x) (*_hdudx.m2o):

• ETA DV/DY (v/y) (*_hdvdy.m2o):

• X-Momentum Advection U DU/DX (u u/x) (*_xmomu.m2o): U component of the momentum advection term in the x-direction

• Y-Momentum Advection U DV/DX (u v/x) (*_ymomu.m2o): U component of the momentum advection term in the y-direction

• X-Momentum Advection V DU/DY (v u/y) (*_xmomv.m2o): V component of the momentum advection term in the x-direction

• Y-Momentum Advection V DV/DY (v v/y) (*_ymomv.m2o): V component of the momentum advection term in the y-direction

• X Bottom Friction (*_xbfric.m2o): X component of the bottom friction

• Y Bottom Friction (*_ybfric.m2o): Y component of the bottom friction

• X Wind Stress (*_xwnd.m2o): X component of the wind stress

• Y Wind Stress (*_ywnd.m2o): Y component of the wind stress

Flow Rate Output Files:

• X Direction (*_qx.m2o): Flow rate in the x-direction

• Y Direction (*_qy.m2o): Flow rate in the y-direction

Related Topics

• CMS-Flow