ERDC/CHL CHETN-I-70
May 2005
c. Enter values of 40 m for the width of damping layers and 1.0 for the damping coefficient and
select OK. The width value for the damping depends on several factors including wave type
and grid resolution. Consult Demirbilek et al. (2004) and Nwogu and Demirbilek (2001) for
details.
In applications where the depth transition from water to land is not gradual, excessive reflection
would occur as the model overpredicts reflection from the coast. To prevent this, place a damping
layer along the coastline. This coastline damping-layer may be defined as:
a. Select the cell string along the coastline.
b. Select BOUSS-2D|Assign BC... and select Damping.
c. Enter values for width and damping coefficients of 20 m and 0.5, respectively, and select
OK. These values allow for partial reflection.
Specify Other Model Parameters: The next step in preparing a simulation is to specify other
model input parameters. Select BOUSS-2D|Model Control to specify Project Title as "Barbers Point
Sample Run." In the Input Data Sets, select Use Cellstrings for damping. For Porosity and Current,
choose None. For Time Control, enter 1,500 sec for duration of the run, and 0.2 sec for the time-step.
For Animation Output, check Output WSE, Output Velocity and Override Defaults toggles. Enter
1,425.0 for the beginning time; 1,500.0 for the ending time; and 1.0 sec for the output interval to
save an animation output for approximately the last five waves. Select the OK button to close the
dialog box.
Save and Run Simulation: The final step before running a simulation is to save the BOUSS-2D
files. Select File|Save New Project and enter BarbersPoint_Tutorial for project name, and click
OK. The simulation may now be launched by selecting BOUSS-2D|Run Bouss. A message will be
displayed for the default location of the model executable (Bouss2d.exe). Click on the folder icon to
select the location of "Bouss2d.exe" file, and click on the Run button. SMS now launches BOUSS-
2D. This simulation takes approximately 1 hr to run on a Pentium 4 processor (3 GHz clock speed)
with a 0.2 sec time-step. The model run time would increase to nearly 3 hr for a grid using 5- 5-m
cells, and the run time would reduce to below 20 min for a grid with 20- 20-m cells.
Visualize Simulation Results: The model will create five solution files that include spatially
varying results at the grid nodes. Three of these are steady state data sets that include the results for
mean wave height, mean current direction, and mean water level. The other two are temporally
varying results, output at user-specified intervals. These include computed water levels and currents
(u and v). BOUSS-2D saves these results in the independent files named BarbersPt_hs.grd,
BarbersPt_mean_uv.grd, BarbersPt_mwl.grd, BarbersPt.eta and BarbersPt.uv. The model can also
write all of these in one binary metafile named BarbersPt.h5 in HDF5 format. When the model run is
completed, the user can select a toggle to read the type of solution files for SMS to display. Refer to
Demirbilek et al. (2004) and the SMS users manual and tutorials for guidance on how to visualize
the model output files.
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