Heat and mass transfer in a multi-porous cavity

Abstract

In this paper, two-dimensional non-linear double diffusive convection in a multi-porous cavity is considered. The Darcy equation, including Brinkman term to account for the viscous effects, is used as the momentum equation. The model consists of two rectangular cavities filled with glass beads having a diameter d 1 of either 5.25 mm (Case 1) or 3.25 mm (Case 2). The smaller cavity is located at the top left corner of the larger one. The larger cavity is filled initially with hot salty fluid while the smaller one contains initially cold fresh fluid. At the initial time, the obstacle between the two cavities was released and the double diffusive phenomena were studied in details. The momentum, solutal, energy and continuity equations are solved numerically using the finite element technique. This transient problem is solved for two different Darcy numbers. For each Darcy number, the influence of the solutal Rayleigh number on double diffusive convection was studied in details. The permeability in the horizontal and vertical direction was assumed identical. A comparison of the intruding force between this case and the open flow case studied by Saghir et al [Int. J. Heat. Mass Transfer, in press] showed that it is inversely proportional to the Darcy number. Finite element modelling results indicate that salinity induces stronger convection than the thermal ones.