[Fraxiel]

I'm currently conducting a CFD analysis of a pusher propeller on a medium-sized aircraft. To study the increase of the drag on the entire aircraft (I have done a separate analysis of the aircraft with CLEAN geometry, meaning no propellers or landing gear).

To do this I have created 2 cell zones. The enclosure and a rotary zone (a cylinder with the propeller geometry subtracted from it) that rotates at a given RPM. My mesh is very high quality and my number of cells is around 15 million. using the mesh motion I set the RPMs and the rotation origin and axis.*
When I set the mesh motion it swaps to the transient solver, moving on I keep getting the error message: Update dynamic mesh failed. Negative cell volume detected.

Noted that I have done this very same method with other projects and it has worked. My issue now is that even when I go back to the old projects I get the same message and the same error. what could be the cause of this issue? I have read that making the mesh COARSER could potentially fix this.
I have tried every possible solution, I've made my mesh so much finer that it has reached 40M, I have decreased my timestep to 1e-5 and I still get this error. I can't find a way to solve this. So Please guys I need your help

[Gert-Jan]

what software do you use?