fluid flow problem in 3D tube

gurunarayana ravi

Can some one tell me how to

form a 3D grid in a 3D tube apply fluid boundary conditions ( inlet velocity,outlet velocity)

I need to know wat r the boundary conditions and what faces I need to select.

It will also be nice if someone can tell how to solve the same problem with heat transfer assuming a constant wall heat flux. I need to know wat faces to select in gambit and the boundary conditions