Numerical Study of Second Law Analysis Using Magnetohydrodynamics on Natural Convection in a Porous Medium with Thermal Radiation and Viscous Dissipation

Abstract

This paper focus on natural convection in the presence of an applied magnetic field for analysing entropy generation and fluid flow phenomena in a porous medium. The numerical technique adopted was the finite difference method. The parameters used for numerically analysing the fluid flows are the Rayleigh number (103 ≤ Ra ≤ 106), Eckert number (10−6,10−5,5 × 10−5) , Forchheimer number (0 ≤ Γ ≤ 1), inverse Darcy (0 ≤ γ ≤ 1), radiation (0 ≤ Rd ≤ 10), Prandtl number (Pr = 0.7,1.0,7.0,10) and Hartmann number (0 ≤ Ha ≤ 30). The numerical results were compared with existing papers and excellent agreements have been made. Findings reveal that as Hartmann increase the streamlines become distorted showing a reduction in the flow rate due to retarding impact of the Lorentz force. Enhancing radiation, leads to the intensification of the flow rate. As Rayleigh number increases entropy generation of the medium significantly increases.