Flow of Gases in Porous Media

Abstract

This paper presents a brief theoretical review of the viscous and free molecular flow phenomena. The equations which describe these two types of flow are applied to flow through porous media and are combined to yield a semi-empirical equation which may be used not only for the viscous and free molecular flow, but also for the transition region between these. Experimentally determined limiting values of the ratio of molecular mean free path to pore diameter are reported. These ratios may be used to indicate the nature of flow in a porous media provided the pore size is known, or they may be used to determine pore size experimentally.

Fluid Dynamics

“…Green and Duwez (99) outlined a method of correlating experimental data of gas and liquid flow through porous metals. Flow of gases in porous media was the subject of Wilson, Sibbitt, and Jakob (295), who discussed the different regimes of viscous flow, viscous slip flow, and free molecular flow. Penner and Robertson (208) presented a method for visualizing flow through woven fabrics.…”

IRRADIATION PERFORMANCE OF THORIA-URANIA FUEL MATERIALS. Quarterly Technical Report No. 1, May-September 1964

“…This.law states that the flow of gas througha circular For an approximation of the type of flow within a tube, the values given for the ratio of the radius r to mean free path k are: 21,23 1. r/k > 100 for viscous flow. 2. r/X < 1 for Knudsen flow.…”

“…Liquid-volume displacement27,28 and flowmeters, such as 31 the wet-test gas meter , rotanneter 24,33,36 , and bubble meter25 have 23,35 been used to measurethe volumetric flow.…”