Hello,

I'm trying to simulate the wind flow over a membrane structure according to your "Double-Sided Membrane" and "Flow Over a Double-Sided Membrane" tutorials and I've run into a problem with correctly defining geometry in case the structure is standing on the ground.

My structure is a saddlespan with 2 side walls which are anchored directly to the ground. The geometry is imported from an .obj file. I'm doing everything according to the tutorials, but on the mesh generation stage there is always an error like this: "Warning: Flow volume [www.72755.5] Tetulator: Failed: Front advance failed: 3028 faces remain". When looking on the Area color map I can see that the mesh on the structure and on the ground plane is not actually continuous at the edges which touch the ground (screenshot: https://www.dropbox.com/s/0f8vy3z434ol8io/Captured_105.png?dl=0 ), so I believe it most probably is the problem. Although it seems logical to me that when I subtract my structure faces from the flow volume all the intersection edges should also be generated. I even tried to move the flow volume a bit higher to make sure that my structure actually intersects the ground plane, but the same error occurs. But when I move the volume lower so that the structure is floating in the air — the mesh is generated just fine. So I'm a bit of at a loss here, how should this intersection be properly done?

Here are some links to the simulation files:
The file with all the geometry right before subtracting imported mesh from the volume:
https://www.dropbox.com/s/4lp2k8imay0v5bd/CAS_18x30_geometry.sym?dl=0

The file ready to run the mesh generation (where the error occurs):
https://www.dropbox.com/s/0u28ku4e4dnqrqu/CAS_18x30_pre-analysis.sym?dl=0