[Matteo_Kamenjasevic]

Dear Foamers,
I am newie in multi region simulations and want to learn mesh this cases with snappyHexMesh. I watched a several videos on YT and I have to say that they are very bad and a lot of confusing. Also I tried to find something on internet and no success. This is my case: heatsink in which fluid flows through and it interfaces a solid with some high temperature. For me in this moment I am not so interese in physics I just want to use snappyHexMesh for multiregion simulations.
For creating groups and triangulation I am using Salome. My question is: should I define this interface between heatsink and solid like just one group, for example "heatsink_to_fluid"?

This is what I did:
For heatsink: "inlet", "outlet" and "walls_heatsink" (this walls are without interface ).
For solid: "walls_solid" (without interface).
And I set this interface like "heatsink_to_solid".
Then I exported this groups in STL files and set up snappyHexMeschDict.
When I run "splitMeshRegions -cellZones" it says that I have one region.
I hope that you can help me with this because I have a project in my Formula Student in Zagreb and want to provide some CFD simulations for my sub-team Cooling.