Mesoscopic simulation of magnetic field effect on natural convection of power-law fluids in a partially heated cavity

Abstract

In this paper, effect of a magnetic field on natural convection of non-Newtonian power-law fluids in a partially heated cavity, has been analyzed by using the Finite-Difference Lattice Boltzmann Method (FDLBM). This study has been conducted for certain pertinent parameters of Rayleigh number (Ra=104 and 105), Hartmann number (Ha=0–60), power-law index (n=0.5–1.5), and length of heated section (H/L=0.25, 0.5, and 0.75), as the magnetic field is applied horizontally. Results indicate that the augmentation of the power-law index in the absence of the magnetic field causes heat transfer to drop. Generally, the magnetic field decreases heat transfer in different power-law indexes. The increment of the magnetic field power declines the effect of the power-law index on heat transfer. The magnetic field for various Hartmann numbers at Ra=104; has different effects on heat transfer with the enhancement of power-law index. At Ra=105 and for Ha=0 to 30, heat transfer falls with rise of the power-law index as the effect is weakened by increase in Hartmann number significantly. The influence of power-law index on heat transfer augments with increase in the size of the heated section.