Effect Of A Sinusoidal Temperature Profile On Entropy Generation Due To Double-Diffusive Natural Convection In A Square Partly Porous Cavity

Abstract

In this manuscript, entropy generation due double-diffusive natural convection and sinusoidal heating on one side inside a composite enclosure is numerically analyzed for various values of some governing parameters. Finite Volume method (FVM) is used to discretize the resulting dimensionless coupled partial differential equations while the SIMPLE algorithm is used to deal with pressure-velocity coupling. The validity of the results obtained by the in-house FORTRAN code is verified by comparison with previous numerical and experimental work. It was found that in the case of comparable effects of temperature and concentration buoyancy forces (N=1), the heat transfer irreversibility increases with increasing α and becomes dominant for α=0.8, resulting in a values of average Bejan number, Beavg>0.5, while at high values of N (N=10), the fluid friction irreversibility dominates for all values of ?. Moreover, the results indicate that for the chosen values of Ra and Da, the entropy generation due to fluid friction is dominant when (Sψ)<1 (partly porous cavity), regardless of Rk, a and N values, whereas for pure porous cavity (Δ=1), Sθ(max) becomes dominant.