Reply To: two interraction body in AQWA

[Shuangxing Du]

I may assume that in your model the external surface is meshed only for the external cyliner. The cylindral surface of the internal cylinder should be modelled as non-diffraction panels and only the bottom surface could be modelled as diffraction surface if this surface is submerged.

In Hydrodynamic time domain response analysis, the relative motions between the hydrodynamic interation structures should be small. If the motions are big, could you please consider to add in some constraints, such as fenders to reduce the translational motions between two structures and to define larger moment of inertia about cylinder axis for the cylinders to reduce the yaw rotations?

The inner cylinder (closed) being below the water level is allowed. If it is totally submerged, you may need to set it as a sumberged structure.  As there is no hydrostatic stiffness for a fully submerged structure, please check if you need to define some structural stiffness such as moorings/fenders to keep this structure in the desired mean location. The heave motion of a fully submerged structure can be observed by either animation or plotting structure position in Z direction.