A mathematical analysis of unsteady flow and heat transfer in a porous medium

Abstract

The unsteady two-dimensional free convective flow through a porous medium bounded by an infinite vertical plate is considered when the temperature of the plate is oscillating with time about a constant nonzero mean. The problem is solved by developing two asymptotic expansions in powers of the frequency parameter ω. For small values of ω, a regular expansion is obtained, and for a large frequency parameter the method of matched asymptotic expansion is used. The effects of the frequency parameter ω, the permeability parameter K and the amplitude parameter ϵ on the velocity and the temperature fields are discussed.