Boundary Definition
 

Hi!!!

I have a cage in the shape of a cuboid. I have drawn a face(face A) inside the cage parallel to the two outer faces (face 1 and face 2) of cuboid. Some circular holes are made on this face A and substracted so that I have holes and a face B (face A-holes).

I have defined one outer face(face 1) as mass flow inlet and other outer face(face 2) as pressure outlet while the other outside faces are walls. I want the fluid to flow from mass flow inlet through these holes and pass through pressure outlet. What should be the boundary type of face B and the of the holes in it.