SimScale CAE Forum

[CFD] Problem with multi-volume simulation (Centrifugal pump)

Dear all,

Thank you for providing this platform for the CAE community.

I am trying to run a CFD simulation for a centrifugal pump (the case is identical to the one in the tutorial, but the geometry is different). I imported the geometry successfully into SimScale,.The geometry consists of two different volumes, one for the static domain and the other for the rotating zone.
The problem is, no matter what I do, I always fail to generate a single-region mesh.
This is the link to my project:

In materials, I believe I need to assign air (I am using air), to all zones, right?

When I try to define the rotating domain as a cell zone and generate the mesh, I get the following error:
“One or more cell zones are adjacent to a flow region cavity. Cell zones’ faces must be inside the flow region.”

Even when I was able to generate a mesh without defining a cell zone, I always receive this error when trying to run the simulation:
“A multi-region mesh was assigned - this analysis-type requires a single-region mesh”

Thank you in advance!


There’s an issue with the geometry. The rotating zone volume should be 100% solid and should intersect with the flow volume (think of the rotating zone volume as a plain, 100% solid part).

In your case, the “impellerdomain” and the “fluiddomain” have an interface between them (which shouldn’t happen, given that they should be fully intersecting with each other):

In your geometry, the blade walls are part of the “impellerdomain” but they should also be in the “fluiddomain”. Check this article for more insights:

I took the geometry to Onshape and made some changes in it. Posting 2 pictures from it here to compare with the pictures from your geometry:

Feel free to use this geometry if you want. It should be good to go:


Thanks a lot for the insight.
So apparently, I have made a mistake assuming that SimScale is like ANSYS Fluent.
In ANSYS Fluent you have to define them separately, and that’s why I have separated them here ( I did the same simulation there and I want to try it here).
Anyway, thanks!
I will change the geometry and get back to you.

Ok Maybe I will try the one you created first haha.
Thanks again.

1 Like