Heat and Mass Transfer Due to Double-Diffusion Convection in a Square Porous Enclosure Occupied by Casson Fluid

Abstract

Heat and mass transfer in a porous cavity filled with Casson fluid are analyzed. The flow behavior of Casson fluid in a porous cavity is investigated due to the realization that most of the fluids exhibiting non-Newtonian behavior come in contact with porous media, particularly, in ceramic processing, enhanced oil recovery, production of glass float, and processing of nuclear waste. The mathematical model of the physical problem consisting of continuity, momentum, energy, and concentration equations is converted into finite element equations and solved by penalty finite element method. The bottom wall of the cavity is hotter than the side walls (T_h > T_c). The top wall of the cavity is adiabatic. On the other hand, concentration is more on the top wall compared to the bottom (C_h > C_c) wall. The side walls are taken to be impermeable to concentration flux. The physical parameters governing the fluid flow are Rayleigh number $\left( {Ra} \right),$ Prandtl number $(Pr)$, Darcy number $\left( {Da} \right)$, Lewis number $(Le )$, buoyancy ratio parameter (N), and Casson fluid parameter $(\gamma )$. It is observed from the obtained results that with the rise in Casson fluid parameter in porous medium leads to enhancement in heat transfer rate, mass transfer rate, and fluid flow intensification.