LHEEA / HOS-NWT

Numerical Wave Tank based on High-Order Spectral method
GNU General Public License v3.0
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Problems in parameter setting and post-processing #37

Open LJM-97 opened 5 months ago

LJM-97 commented 5 months ago

Hi, @gducrozet I have encountered some problems when using HOS-NWT. Could you please help me to solve them? The issues are lists below.

i) "n1" and "n2" are interpreted as "number of modes/points". If we run a 3D wave simulation, should "n2" (the number of discrete points in the y-direction) be set to greater than 1? However, the web page still allows n2=1 in 3D conditions. So I'm really confused about "n2". Also, could you tell me what the setting criteria for "n2" is? How does it relate to wave length and height?

ii) In 2D simulation, p1=M, p2=1; In 3D p1=p2=M. In general, can I keep these settings unchanged and get a relatively normal result?

iii) I set up the wave height probes in the 3D domain, but the "prob_ele" file is empty, and in the "Results/probes.dat" the elevation data is missing, and only the time series exists. How to get the probe monitoring data? (see Figure 1 & 2, please.) 9531a14b56d77dce1668a38e2c375dc 2c91cfdf0fe8a68333732d22c42637f

Have a nice day! Best regards, Jiaming Liu

gducrozet commented 5 months ago

Hello @LJM-97

To answer your questions:

i) For 3D simulations, you should indeed provide n2 greater than 1 since it corresponds to the discretizaiton in the direction perpendicular to the mean wave direction. However, nothing prevents you to solve the wave-field with n2=1... except that it is consequently unidirectional wave field. Regarding the choice of values for n2, similar to n1 it is closely linked to the size of the domain and the type of sea state you model. What I can advise to see if your choice of discretization is correct is to look at the modal amplitudes (use the output imodes set to 1). you will see if your wave field is correctly discretized in kx and ky and you may adjust n2 and Ly in consequence.

ii) yes

iii) you should check the content of your prob_elevation.inp that should contain for each probe x and y location