RT Journal Article ID 72460bbe776a6c62 A1 Alloui, Zineddine A1 Vasseur, Patrick T1 NATURAL CONVECTION IN TALL AND SHALLOW POROUS RECTANGULAR ENCLOSURES HEATED FROM BELOW JF Computational Thermal Sciences: An International Journal JO CTS YR 2016 FD 2016-09-07 VO 8 IS 2 SP 163 OP 176 K1 natural convection K1 porous medium K1 parallel flow approximation AB The Darcy model with the Boussinesq approximation is used to study both analytically and numerically natural convection in a porous medium saturated by a Newtonian fluid. The geometry considered is a rectangular cavity heated from below and cooled from above by a constant heat flux while the sidewalls are maintained adiabatic. The governing parameters for the problem are the thermal Darcy-Rayleigh number R and the aspect ratio of the cavity A. In the limit of extremely confined geometries the parallel flow approximation is used to predict the flow behavior in the case of a tall vertical layer (A >> 1) or shallow horizontal one (A << 1). For a tall cavity, the existence of multicellular flow patterns, consisting of m vertical cells, is predicted by the present analytical model. Also, for a shallow cavity, it is demonstrated that the flow pattern can be either unicellular or multicellular. This is confirmed by the numerical results obtained by solving the full governing equations. PB Begell House LK https://www.dl.begellhouse.com/journals/648192910890cd0e,2588198a050b6dad,72460bbe776a6c62.html