in gambit ,how to distinguish 2d-section between pipe and cube.

Zalhit,

I'm also confused with the question. I think if u take a mid axial section surface from a pipe or a cube it is same (quadrilateral). So neither gambit nor fluent can detect it as a part either pipe or cube. It is being solved as a flow field with bounded by two line-walls.

Alamgir

it depends upon what solver you select in fluent . 2-d or axi-symmetric