Input wave parameters in a coastal simulation

Product(s): OpenFlows FLOOD
Version(s): 10.03.XX.XX
Area:  Help and Documentation



This article details how to setup a coastal simulation with OpenFlows FLOOD taking into account waves. Wave parameters can be read or calculated by MOHID Water numerical model (engine) and used to compute their influence in currents and water elevations as well as computing bottom shear stress which directly impacts sediment transported namely through controlling erosion and deposition fluxes. 

Wave parameters can be typically calculated by an external wave model (e.g. SWAN, STWAVE, REFDIF, WWIII, etc). For some of these wave models (e.g. SWAN) there are in MOHID some conversion tools that allow to convert the wave model results into HDF5 format (the standard input/output format for MOHID Water). Once you have converted the wave model results to HDF5 they will be ready to be read by MOHID Water as described in this article. 

Additionally, for some types of applications (e.g. reservoirs, lakes, some estuaries/bays where waves are mostly generated locally, etc.) MOHID Water can also compute wave parameters. This feature is however not covered in this article. 


In order to run a simulation with waves (using MOHID Water), first go to the simulation properties and add the Waves module to the list of active modules in that simulation as seen below. 

The wave module should appear in the left list of modules. Then press OK. 

Then go to module Model configuration dialog and select in the Modules section, set the option "Enable Waves module" to True (as shown below) .

In order to allow for the configuration of the wave-current interaction options in the Hydrodynamic module, the user interface dialog has to be deactivated so that the configuration is done by editing the text files. You can find out how to do it here.

Then in the Hydrodynamic input data file set the following options. For 2D applications: 

WAVE_STRESS                     : 1

For 3D applications: 

WAVE_FORCING_3D           : 1

Then go to the Waves module configuration file and double click to open the text editor (the Waves module does not have a user interface dialog to configure the calculation options, it has to be via the text editor). 

Depending on the type of simulation you have to then define the main options in the Waves module input data file. For example if the user wants to compute wave-current interaction, it will have to activate the following options: 

WAVE_PERIOD                  : 1
WAVE_HEIGHT                  : 1
WAVE_DIRECTION            : 1


For 3D simulations the following options will be required also: 

WAVE_LENGTH                 : 1

And for computing wave shear stress: 

WAVE_UBW                       : 1

The above mentioned wave parameters are normal outputs of a wave model like e.g. SWAN. 

In order to read the information then the following blocks must be defined in the Waves input data file: 

NAME                     : significant wave height
UNITS                     :  m
FILENAME             : ..\General Data\Waves\Waves.hdf5

NAME                     : mean wave direction
UNITS                     : degrees
FILENAME             : ..\General Data\Waves\Waves.hdf5

NAME                     : mean wave period
UNITS                     : s
FILENAME             : ..\General Data\Waves\Waves.hdf5

If RADIATION_TENSION      : 1 is defined then set: 

FILE_IN_TIME                       : HDF
FILENAME_X                         : ..\General Data\Waves\Waves.hdf5
FILENAME_Y                         : ..\General Data\Waves\Waves.hdf5
HDF_FIELD_NAME_X           : wave stress X
HDF_FIELD_NAME_Y           : wave stress Y
DEFAULTVALUE                    : 0. 0
REMAIN_CONSTANT            : 0

If the options WAVE_LENGTH : 1 is active, then define: 

NAME                    : wave length
UNITS                     : m
FILENAME             : ..\General Data\Waves\Waves.hdf5

If the option WAVE_UBW   : 1 is defined, then: 

NAME                     : Ubw
UNITS                     : m/s
DESCRIPTION       : orbital velocity near bottom
FILENAME             : ..\General Data\Waves\Waves.hdf5