flow over cylinder CHTmultiregion
 

Hi,
I worked very little with Openfoam and I'm trying to work on chtmultiregionfoam for flow over cylinder, but I'm struggling to generate the mesh. I'm not even sure if I have to use snappyhex to create this kind of mesh. Can I generate this type of mesh using only openfoam or is it necessary to use external meshing softwares? I would appreciate if I can get some kind of help and guidance to how to go about it. Thanks!