Ingrid Machecler
Ansys Employee

 

Good morning, 

Your stucture is indeed symmetrical but your mesh is not. So this is likely introducing small numerical errors. A way to check this is to generate the roll-roll and pitch-pitch damping and check that these above coefficients are small compared to the diagonal terms.

A possible solution would be to model a 1/4 of the structure and mesh it and use the SYMX and SYMY. 

Note that the wave directions should be within this quarter (ie, 0-90deg) and you won’t be able to visualize the pressure and motion but you can use AqwaGS instead.

I hope this helps.

Ingrid