Hi, I want to run a chtMultiRegionSimpleFoam simulation and therefore I am making a multi region mesh with snappyHexMesh. My case consists of a fluid zone (grey) and a solid zone (red). I struggle with getting a good multi region mesh in the snapping phase. I played around with the different parameters (nSmoothPatch, tolerance, nSolveIter etc.), but I keep getting "ugly" cells at random locations as you can see in the image. Therefore, my question, which parameters do I need to tune to improve these cells for a good multi region mesh? And why do I get these strange shaped cells in the first place? Thank you