Ansys Learning Forum Forums Discuss Simulation Fluids A small change on geometry lead huge change on hydrodynamic. Reply To: A small change on geometry lead huge change on hydrodynamic.

Shuangxing Du
Ansys Employee

Aqwa Hydrodynamic Diffraction analsyis does not need any surfaces inside the hull, and all the external surfaces' normal directions should point outwards.  Please aslo check the hydrostatic stiffness matrix, expecially the heave-heave value.

It is noticed that the heave peak values of these two configurations are evidently different, it could be helpful to find out what is the natural frequency of heave by including more incident wave frequency points near 0.3 and 0.9 rad/s.