Numerical investigation of two dimensional natural convection and entropy generation inside a porous square enclosure with sinusoidally heated wall

In this paper, effect of sinusoidal heating on natural convection heat transfer and fluid flow has been studied in two dimensional square cavity saturated with porous medium. The governing equations have been formulated using Darcy-Forchheimer model and Boussinesq approximation. Finite volume method has been used to solve the governing equation. Computations are done for the wide range of Rayleigh number, Ra = 10(3) - 10(6) and Darcy number, Da = 10(-5) - 10(-3) considering air (Pr = 0.71) as working fluid. In this analysis, it is observed that in the presence of sinusoidal heating of the bottom wall, transition from conduction to convection mode of heat transfer occurs at 10(4) <= Ra <= 10(5). It is also found that at high Ra and high Da, fluid friction irreversibility dominates the heat transfer irreversibility in the cavity and the maximum entropy generation is found for Da = 10(-3) and Ra = 10(-6) in this parameteric study.