Heat transfer and entropy generation of laminar mixed convection in an inclined lid driven enclosure with a circular porous cylinder

Abstract

Convective heat transfer and entropy generation in an inclined lid driven square enclosure with a circular porous cylinder positioned at the center have been investigated numerically. The governing transport equations within the porous media are treated according to the volume-average theory while the transport phenomena in the rest of the enclosure are represented with Navier–Stokes equations. The bottom wall of the enclosure is assumed to have higher temperature than the top wall and the sidewalls are insulated. In addition, the top horizontal wall is moving in its own plane with a constant speed while all other walls remain stationary. Computations have been conducted over a wide range of pertinent parameters: Richardson number (Ri = 0.01, 1, 5 and 10), Darcy number (Da = 10−5, 10−4, 10−3 and 10−2), and inclination angle (α = 0, 30, 45, 75 and 90). Results revealed that the effects of Darcy number and inclination angle on heat transfer depends on the Richardson number. The effect of the inclination angle on the heat transfer and entropy generation inside the enclosure is more noticeable at high Richardson numbers. Second law analysis also indicated that the proportion of the irreversibilities due to the fluid friction and heat transfer varies as the scrutinized parameters change.