CGWave - Tide

[Jose Maria]

Hi again. Sorry for being a bit "loud".

I am running CGWave in low tide. I succeded after the advice by John (thanks again).

Now I am trying to run the same domain in high tide (range = 3.50 m, aprox). So I repeated exactly the same process:

1. I add 3.50 m to my bathymetrical data, helped by surfer
2. Calculation of the size, via wave lenght
3. Load coastline
4. Build semicircular domain
5. Build the mesh from the size dataset
6. Renumber both nodestring and assign BC
7. Built the 1-D lines
8. Fill the control model (H = 5.0 m, T = 15 s)
9. Run the model
10. ¡¡¡ I got H = 20 m or so in the boundary !!!

Where can be the mistake?

Thank you very much.

[John Howlett]

Do you have wave breaking on? With wave breaking off, the wave height will be larger than with it on.

To turn on wave breaking:

• Select CGWave | Model Control. The Model Control Dialog will appear.
• Check the Wave Breaking toggle.
• Click OK.

Also, as SMS reads the output file it asks the user if breaking should be applied to the solution. If breaking was on in the simulation, this is not required. If the user wishes to see the raw wave data, the option to break should be turned off as the solution is read. In this case, the default can be left on to break the waves. While reading the solution, SMS creates several data sets. These include steady state data sets representing the wave height, wave phase, and wave direction along with the sea surface and particle velocities and pressures at the water surface, midpoint of the water column and bottom of the ocean. These functions are grouped under Mesh in the Project Explorer. In addition to these static or steady state data sets, SMS process the output from CGWAVE to create two transient data sets. A scalar data set named Wave Surface along with a vector data set named Wave Velocity represent the water surface and wave velocity through a wave period. The period is broken into 20 steps and the wave is allowed to prorogate through the domain.

The following test case posted on the xmswiki, is a good example of this:

Tests 19 & 20

As in Test 18, but with nonlinear breaking on and off. Test pertains parameters in Zhao et al., (2000, Coastal Engineering).

Max wave height with breaking:

• Min 0.000749537
• Max 0.0418934
• Range 0.0411439

Max wave height without breaking:

• Min 0.000490395
• Max 0.0597216
• Range 0.0592312

[Jose Maria]

O.K., thanks. You are being a great help.