Marine modelling: Water Surface interface (boundary or not)?

Hi anyone,

As a newbie, I’m trying to reach a point where I can perform a full CFD on my CAD model hull below the waterline - a catamaran.
However, not being able to find many worked eg’s or similar videos on this, I am struggling to understand if I should position my model at the air/water interface & define the boundaries for the simulation ‘under’ the model or if in fact I should be doing something else - given the error I’m getting?
One thought I had, was to simply slice my model horizontally at the waterline before importing it - however, I (think) I’ll have to position it intersecting on the top boundary on the CFD setup so I don’t get ‘interference’ from the flat, slice of the hull on top?
(hope that makes sense?)

Jumping ahead a tad, I can’t see how to get from this step to the mesh step?

Thanks in advance you pro’s!

Hi @mijeau , you are most likely looking for a free surface simulation or a multiphase simulation, the latter we have in the SimScale platform, as the multiphase analysis type, or for premium users, the subsonic analysis type. This would model both fluid and ai and capture the 3d deformation of the water surface plane also.

That said, the issue in your screenshot has nothing to do with where you are positioning, and most likely is a sign that the geometry is not watertight or high quality enough to perform the operation. The most efficient workflow would be to simplify the model as just the hull shape without any details and use that instead.