EFFECT OF ANISOTROPY ON NATURAL CONVECTIVE FLOW THROUGH A RECTANGULAR POROUS SLAB

The natural convective flow and heat transfer, within the framework of Boussinesq approximation, in an anisotropic fluid-filled porous rectangular slab subjected to end-to-end temperature difference have been investigated using a Brinkman extended non-Darcy flow model. The studies involve simultaneous consideration of hydrodynamic and thermal anisotropy, when the principal axes may or may not coincide with the coordinate axes. The flow and temperature fields in general are governed by Ra, the Rayleigh number, AR, the aspect ratio of the slab, K*, the permeability ratio, k*, the thermal conductivity ratio, the angles (Pi and 4)2, the principal axes made with the coordinate axes, and Da, Darcy number. Numerical solutions employing the successive accelerated replacement (SAR) scheme have been obtained for Ra = 500, AR = 1, 0.5 <= K* <= 5, 0.5 <= k* <= 5, 0 degrees <= phi(1) <= 90 degrees, 0 degrees <= phi(2) <= 90 degrees, and 0 <= Da <= 0.1. The results obtained and the conclusions drawn describe the composite effect of non-Darcy flow when the principal axes describing anisotropy in permeability and thermal conductivity do not coincide with the coordinate axes.