I tried to perform a CHT simulation but I got stuck in mesh generation. How can I “divide” my mesh into solid and fluid parts? The problem I am interested in is basically two concentric cylinders, in which I want to simulate heat conduction only in the external one. There is air between them. I did not find any working case in your library. Is CHT functonallity (chtMultiRegionSimpleFoam solver) really working at the moment?