Steady-state free convection in right-angle porous trapezoidal cavity filled by a nanofluid. Buongiorno's mathematical model

A numerical study of the steady free convection in a right-angle porous trapezoidal cavity filled by a nanofluid using Buongiorno's mathematical model has been performed. The analysis has been done for different values of the governing parameters Nb, Nt, Nr, Le, A and Rayleigh number Ra in the range 50 <= Ra <= 1000 using a finite difference method. It is found that single cell is formed inside the cavity independent of the governing parameters. An addition of the nanoparticles can lead to both an intensification and attenuation of the convective flow and heat transfer in dependence on Nb, Nt, Nr, Le, A and Ra. The results indicate that there exist significant changes in the flow and temperature fields as compared with those of a differentially heated square porous cavity. These results lead, in particular, to the prediction of a position of minimum heat transfer across the cavity, which is of interest in the thermal insulation of buildings and other areas of technology. (C) 2015 Published by Elsevier Masson SAS.