Knudsen Flow through a Porous Medium
William C. Strieder, Stephen Prager · The Physics of Fluids · 1968
Rigorous bounds on the permeability of a porous medium to Knudsen flow are formulated by applying the variational procedure of DeMarcus. The bounds are expressed in terms of certain averages characterizing the random-pore geometry. Explicit calculations are given for a model pore structure generated from randomly overlapped spheres.