Numerical study of natural convection heat transfer in an inclined porous cavity with time-periodic boundary conditions

Kalabin et al. (Numer. Heat Transfer A 47, 621-631, 2005) studied the unsteady natural convection for the sinusoidal oscillating wall temperature on one side wall and constant average temperature on the opposing side wall. The present article is on the unsteady natural convective heat transfer in an inclined porous cavity with similar temperature boundary conditions as those of Kalabin et al. The inclined angle. of the cavity is varied from 0 degrees to 80 degrees. The flow field is modeled with the Brinkman-extended Darcy model. The combined effects of inclination angle of the enclosure and oscillation frequency of wall temperature are studied for Ra* = 10(3), Da = 10(-3), epsilon = 0.6, and Pr = 1. Some results are also obtained with the Darcy -Brinkman -Forchheimer model and Darcy's law and are compared with the present Brinkman-extended Darcy model. The maximal heat transfer rate is attained at the oscillating frequency f = 46.7 pi and the inclined angle phi = 42.2 degrees.