Nonsteady flow of non-Newtonian fluids through a porous medium

In this paper, the nonsteady flow of power-law fluids with a yield stress through a porous medium is investigated. In order to illustrate the rheological behaviour effects on pressure and flow rate distributions, a flow system of practical interest was analysed. The approximate solutions in a closed form were obtained by using the integral method. For a short time, these have been formulated in terms of a moving boundary problem. The flow deviation from Newtonian behaviour was emphasized by means of several dimensionless groups. These have been found to be relevant in evaluating the rheological effects on steady and nonsteady flow behaviour through a porous medium.