Flow configuration influence on Darcian and Forchheimer permeabilities determination

Abstract

Within the framework of fuel cells, porous materials are used for the filtration purpose. Determining physical properties like porosity and permeability are of utmost importance to predict and manage filtration efficiency of these materials. Permeability of material is often determined experimentally in laboratory with disc samples (the fluid is flowing through the porous material) that are not exactly similar to the tubes of realistic operating conditions (fluid is mainly flowing tangentially to the surface and only a small part is flowing through the material). Thus, the effect of a secondary outlet on the Darcian’s permeability characterization should be studied. In the current paper, we present a new test bench to determine experimentally the Darcy’s and Forchheimer’s permeabilities for a porous media by taking into account two outlets. The pressure, mass flow rate, and temperature are registered for three different setups: with secondary outlet (S.O) (a) 0%, (b) 50%, and (c) 100% open. Then Darcy’s and Forchheimer’s permeabilities for these three cases are calculated and discussed in detail. It has been found that the S.O opening does not affect the Darcian’s permeability, but have substantial influence on the Forchheimer’s one.