Reply To: Ansys 2 way FSI Issue

[Rahul]

This time it failed in Fluent with negative mesh error. When this happens, it is often because unreasonable displacements were received by Fluent. Since the Fluent mesh collapsed, you should check if the incremental displacement sent to Fluent was reasonable.

It is important to ask here is why are the forces/displacements oscillating with increasing magnitude? If the problem here is due to unstable coupling between the force and displacement on the interface and the displacements calculated are over-shooting the correct position, resulting in an collapsed mesh.

Have you tried

• reducing time step?
• Use under-relaxation of data transfer?

Share the dynamic mesh settings being used for this case.