CFD Simulation Mesh of propeller


I try to simulate the air flow in a closed chamber with a rotating propeller and some walls.

Project link: SimScale

Walls and propeller are deleted by boolean operation from the bounding area and I created a rotating cylinder. The problem is, that when meshing is finished, the walls of the propeller are omitted. Is there any suggestion about a solution? When meshing with a boundary box instead of the outer wall everything is fine.

Any suggestions?



Hi Andreas!

I saw that in the latest mesh settings the walls and the MRF remain in the mesh, did you figure out the issue by yourself then or am I still missing something?



Hi jousefm,

I tried two more times:

  1. I build the rotating cylinder around the other wall part. The result is the same, the inner walls will be omitted. Thus, I suppose, the cause for not-meshing is related to the rotating cylinder.
  2. I tried to build the rotating cylinder by using geometry primitives, but this doesn’t work.
  3. I tried to move the origin of the rotating cylinder to the outer wall of the fan surface. Still no meshing.



Additional: I also tried to activate Multi Region Meshing. Then meshing is done properly, but simulation is not running

@andi5785: please read description of similar project I did last year:

Internal CFD with MRF (2019)



Hi Retsam,

thanks for your reply. I already knew your project and adapted most of that :wink: Thanks for that.
So the only difference is that I can not put the rotating cylinder to the external region. Maybe this it is? The rest seems to be very similar for me.

Anyway I now found out that its working when I define a surface refinement to the rotating cylinder with cell zone. It seems that the rotating cylinder is “shadowing” the rest otherwise.

Simulation is running now.



1 Like

That is the correct way to define MRF zone. Great.


Just want to add that useful link for MRF for other users: