Heat Transfer and Entropy Analysis for Mixed Convectionin a Discretely Heated Porous Square Cavity

Abstract

The present study is a numerical investigation of the irreversibility and heat transfer properties of a steady laminar mixed flow in a square cavity, filled with a saturated porous medium and heated by a discrete set of heat sources. The continuity, Navier-Stokes, energy and entropy generation equations have been solved by a finite volume method. Both heat transfer irreversibility and fluid friction irreversibility have been taken into account in the computations of entropy generation. Simulations have bee carried out for Reynolds number Re=20, 40, 80, 100, 200, Darcy number, Da=10−5-10−1, Prandtl number, Pr=0.015, 0.7, 10, 103, and aspect ratio, D/H =0.05, 0.10, 0.15, 0.2, 0.25, expressly considering the influence of such parameters on the entropy generation and heat transfer processes. The effect of the irreversibility distribution function and aspect ratio has been also taken into account. The results are presented in terms of entropy generation, Nusselt and Bejan numbers. Finally, a general correlation between all these parameters is determined on the basis of the present findings.