[MichiMichi]

Dear all,

right now I try to establish an FSI simulation of two elastic flaps which are deformed by water flow (or air) in a rectangular duct (2.5 D). The long term aim is an FSI simulation of native heart valves.

I am struggling around with the induced contact of the elastic flaps.
In the first figure you can see the entire model and in the second figure you see the moment when the simulation crashes (negative cell volumes), as the tet elements are getting too small.

I am using a tet mesh with prismatic elements around the elastic flaps. Diffusion smoothing (diff parameter = 1), local cell, local face, region face remeshing. I DO NOT want to use 2.5 D remeshing as my model will go into the 3-D space anyways.

Has anyone experience on how to get contact in an FSI simulation? I understand that in my case the flaps won't be able to close completely as I will separate the fluid zones and get infinite pressures. However in the later case (3D) I will get contact of the structural parts in some places.

My idea right now is to make FLUENT delete the tet and prism elements if the flaps are getting closer and closer until 1 or 2 prism layers are in the tiny gap, but I do not know how to do it...

Thanks a lot

Best
Michael