The mesh contains more than one volume

Hey guys,

The new acis (.sat) file support works perfectly for me. I’m finally able to export my model directly from Revit into SimScale and mesh it successfully.

However, now I’m running into the problem that my mesh consists of multiple independent volumes, which results in my simulation failing. Does anybody know how to fix that? Ideally without having to use any other CAD tool.

Link to my simulation here:



Hi Seb and sorry for the late response!

Never encountered this issue before so maybe one of our @power_users might help you out here.



Hi @pi3141, so the issue is that you have many cell zones representing a single fluid volume, they cannot be made to interface each other. These zones are not connected and therefore will cause issues. Cell zones can be used in advance concepts for things like sources or porous media.

To work around this the duct will need to be combined into a single solid.

Hope this helps,


Thanks @1318980. I was able to fix the issue by exporting the model from Revit as .sat (ACIS) file. Then I imported it into Onshape, combined all volumes via the boolean operator and exported it from there as Parasolid, which I could successfully import into SimScale.

Unfortunately the direct import from Onshape failed.

It also would be great if there is a function within SimScale to combine multiple bodies into one simulation domain.