in complicated models like a swirl 3d model.after i meshed model some region must not be wall and that regions must be free for flow of fluid but i don't know which one of properties in gambit must be select before i think that i must choose interior for that faces but it was not correct. please help me about complicated models . thank you. arash shahin

i dont understand clearly what your problem is, but i advise you to define that regions you want flow through as pressure outlets. it's the easiest thing to do. it's so crazy that i might work.

i mean about two beside face that we must create for meshing but these faces must not be the wall. infact these faces must be there only for meshing we have to create these faces.in fact we create two seperate volume with one common faces . and my problem is iin this common face. thank you. A.Shahin

you have do define them as two different volumes in Gambit -> Zones -> Continuum FLUENT take care of the internal face automatically when you import the mesh into that.

but when i import them to fluent fluent take these faces as the wall automatically.

it doesn't happen if you do the same thing I said, even if that happens you can change that wall to interior in FLUENT, boundary condition menu