Learning Forum

[liangjb27]

I am doing hydrodynamic research in AQWA of NAULILUS-10 semi-submersible floating platform, whose edges of four columns are all tangent with the rounded corners of damping plate in platform bottom like the second figure. In my research, the position and size of columns need to be change, so edges and rounded corners are not tangent any more, there is a gap between them like the third figure. A significant change on frequency hydrodynamic, e.g., RAO, radition damping, added mass, can be observed although this change is tiny and the mass, central of mass and rotation inertia is unchange. NO.4 to 7 show this change in RAO and radiation damping.

In my opinion, it is unnormal because the change of hydrodynamic should be continuous. So, how can i improve this situation or is it a limitation of AQWA?

Hope you reply! Thanks.

jb

[Shuangxing Du]

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.