Learning Forum

[Rahul]

It is a common error in FSI simulations, where an element formulation error due to excessive element distortion in the Mechanical APDL solver. When this happens, it is often because unreasonable forces were sent to Mechanical APDL. 

Check whether the force sent to Mechanical was too large(you can check this from SyC log file). This can happen if Fluent didn’t converge, or if there is an FSI instability due to similar densities between solid and fluid.

Using under-relaxation on the data transfers can help here. This will make the solution more stable at the expense of more COUPLING ITERATIONS to reach convergence.