mesh related problem with high courant-number at edge
 

Hi everyone,

I am trying to simulate a pitching floater in a numerical wave tank in 3D. I am using ihDyMFoam and a dynamic Mesh.
One edge of the floater is curved. SnappyHexMesh is creating quite skew faces here, which I am not able to remove. If I lower the values for maximum skewness in the meshQualityControls I get cells that stick out and can't be snapped in again with snapEdge. Making the refinement on the surface coarser or finer also doesn't change the situation.
The problem that I am facing now are quite big courant-numbers only in these cells (See attached picture) . And this happens already after 0.2 seconds, so long before the wave is supposed to hit the floater. Right now I am using a timestep of 0.001 s and I don't really want to lower it just because of these few cells.
Does anyone have an idea how to deal with this problem?

Thanks for you help!
Cheers,
Mona

Update
 

Update: After 0.47 seconds the courant-number explodes and the simulation crashes. I think its because of this one cell on the corner that you can see in the 2nd picture at time 0.45.

Did you find any solution ?

Kind of... I am simulating in quasi 2D instead now. So I am just using a thin slice of the body. It was much easier to achieve good mesh quality in that way, and its faster ;)