Free and Mixed Convection in a Doubly Layered Porous Medium

Convection in a horizontal, doubly layered porous medium has been investigated numerically. Both natural and mixed convection are considered for steady state heating from above. For natural convection, the effects of Rayleigh number on the Nusselt number are investigated. For mixed convection where a uniform flow enters at the side wall, the effects of both Rayleigh number and Peclet number are studied. The effects of the thickness of one layer as well as the length of the heated zone are also examined. Further, the permeability and the thermal conductivity ratios of the lower layer to the upper layer are varied from 0.1 to 100.0 and from 0.2 to 5.0, respectively.