[tinucci]

So I have a mesh of a radial fan I have generated with Fluent Meshing (Normal Meshing module isn't able to generate an appropriate mesh) which consists of two volumes: a fixed one and a rotating one.



The problem is that when setting up the case and making the rotating mesh rotate, it works for a couple of iterations and after that it gives a negative volume error message. I have even tried the simplest case of a rotating sphere alone, following the same workflow and the problem is the same.



The radial speed is and needs to be 105 rad/s and I can't make it slower, and the timestep is aproximately 1e-4 s. The mesh is sufficiently fine with about 15M cells. And I am sure the parameters when setting up the mesh motion are fine.



The only thing I can think of is the need of Fluent Meshing to treat the interface as a shared face, which the normal Meshing module doesn't require, and thus not showing then the Mesh Interfaces option on the Fluent Solver.



Any help is appreciated, I am lost on how to solve this.

[tinucci]

I have also tried splitting the faces afterwards in the Fluent solver but they remain as wall boundaries and can't be set as interfaces...