Flow Through Porous Media, Filtration Models

Abstract

So far as the dimensional nature of characteristic parameters and the meaning of dimensionless variables is concerned, filtration flows are much the same as those forming the subject of the previous chapter. However, the physical picture of filtration flows and the fields of their application are so different from the ‘free’ flows that they are usually studied separately. In accordance with this convention it is intended to analyse filtration flows by introducing this separate chapter. When referring to filtration we refer to the motion of so-called gravitational liquid, continuously occupying the pores of the granular (or porous) medium. Unlike the ‘hygroscopic water’ or ‘pellicular water’, gravitational water (or, in general, fluid) is not subjected to the action of tension forces directed towards the surface of solid particles. Gravitational fluid, which forms the subject of filtration, moves, under natural conditions, because of gravity forces alone. (See the classification and the description of various components of water in soil.1,2,3,4)