Hi,

I'm trying to model a 3D wind turbine using moving mesh method.

My case is unsteady duo to rotation of turbine.

I used different mesh elements in my mesh such as tet, hex/wedge...

Maximum skewness is 0.84. after running iteration FLUENT gives this error: "non-positive volumes exist" however when I import the mesh into fluent after checking grid there is no problem. Also I tried this mesh for unsteady case with moving mesh method and it worked. !!!!

I really wonder what can be the problem. if its from mesh or setting before iteration.

should I use interface between zones with different mesh elements or interior is okay?

the second question is if I have to use interface instead of interior for moving boundaries.?

Or anything else..

I appreciate any help.

Regards,

Amir

You need to disconnect your rotating domain from your stationary domain inside GAMBIT. You need to specify interface for the moving boundaries.

Have you tried using MRF? The best way to do unsteady moving/sliding mesh, is to convert your MRF case to sliding mesh. Ths is done via TUI

grid/modify-zones/mrf-to-sliding-mesh

This will setup everything for you accordingly.

Hope that helps.

Dear Zongtwi,

I tried to disconnect and it works.

Thank you so much,

Regards, Amir.