Reply To: 2 way coupled FSI for ball bearing

[Rahul]

Negative cell volume detected in Fluent. You can open the Fluent results and check the exact location of failure. I guess it is in the lubricant thickness region between the ball and the race. Have a sufficient number of cells of good quality in that region. 

You can refer 'Mesh Folds within the First Coupling Steps' in the user guide: 42.6. FSI Setup Recommendations for Fluent-Mechanical Couplings (ansys.com)