Entropy generation for unsteady natural convection and radiation within a tilted saturated porous channel

The problem of entropy generation for unsteady natural convection and radiation in a tilted open-ended channel, submitted to uniform hot walls temperature and filled with an isotropic fluid saturated porous medium is outlined. The present study is carried out using the Darcy flow model. The local thermal equilibrium assumption is assumed. Viscous dissipation effects are taken into account. The radiative coupling problem is solved numerically by the finite volume method. Present solutions are compared with known results from previous published work. Excellent agreement was obtained between results that validate the used computer code. The results show that the global heat transfer rate depends slightly on the viscous dissipation term but is strongly subordinate to the tilted angle. Moreover, the calculation of entropy generation maps is feasible and gives us a measure of the degree of irreversibility of the convective flow.