Consider an idealized porous material consisting of straight, cylindrical pores of diameter d.

Consider an idealized porous material consisting of straight, cylindrical pores of diameter d.

Assume that all pores are parallel to the x, y, or z axes and that they intersect at points

described by a simple cubic lattice of dimension l >> d. The overall dimensions of the sample of

this material are of the order of L, where L >> l. The volume flow rate Q in a single pore

segment is described by Poiseuille's law:

Where ΔP is the pressure drop per segment. Evaluate the permeability for this material.