Flow through porous media. Examination of the immobile fluid model

A model is examined which postulates that during permeation a fraction of the interstitial fluid may not joint in the general flow. If valid, this model could explain differences between data and flow equations in which it is usually assumed that all of the interstitial fluid is mobile. The Kozeny—Carman equation is recast in a form enabling the effective particle volume and effective surface area to be obtained from measurements of flow rates at several different porosities. Both flow through porous media and sedimentation are considered. Good fits to data for aqueous systems are reported.A model in which fissures between protuberances on the particle surface restrain the movement of fluid films is suggested and found to be in reasonable agreement with the results.Related information from other topics involving the interaction of fluid with porous media including capillary potential and streaming potential is introduced. The model is discussed critically and suggestions are made for work designed to further test the model and its implications.