Hi I am modeling a heat transfer flow in channel with porous block (partielly blocked). I have problem to specify the interface prous/clear fluid. thanks.

You should define the porous region as a seperate surface and name it differently in Gambit while you're making your model. Then activate the porous region condition in the Fluent when imported.

Amir

Hi Amir, How I can define the realtion betwwen the two faces (in 2D), subrtact the block face from the channel face or slight the faces?

You should geometrically divide your porous region from the main region in order to be able to define the specific porous region boundary conditions on that.

the tow face have connected edge or sepate edge (the edge that separate faces is common or each face has prpoer edge).

Edge is common