SimScale CAE Forum

Multi region meshing error


I am trying to visualize flow of air through the geometry. I made a bounding box (wind tunnel) and provided inlet velocity and outlet pressure.
While running simulation, this was the error: A multi-region mesh was assigned - this analysis-type requires a single-region mesh.

Project link:

I found that many others had the same problem but the solutions on those pages didn’t help. Can someone help?


Hey @mail_manas_shr,

You need to create the flow domain. Currently your geometry consists of 2 solid regions. For your geometry, you can just run a closed inner region operation.

Then you assign one of the internal faces and click apply. You will end up with a flow domain that is suitable for you to run your sims:




Problem has been resolved, thanks a lot!


Hi, I can see that you all are very smart here. I would need help.
I need to model mesh for the flow domain, basically I need to model a flow domain.
I do not have version of the Simflow that allows to perform operations above, do you have any advices where I can model mesh and flow domain the most simple and fastest way? SW, Inventor, autocad?


I suggest OnShape…