Magnetohydrodynamic Natural Convective Hybrid Nanofluid Flow in a Square Enclosure with Different Blocks

Magnetohydrodynamic natural convection of Cu–Al2O3/water hybrid nanofluid in a square enclosure in the presence of thermal radiation was studied. A hot square block and a cold elliptical block were considered inside the enclosure. The dimensionless equations were solved using the finite element technique. The flow and heat transfer behaviors of the fluid were analyzed by velocity distribution, isotherm, local Nusselt number and average Nusselt number with varying Rayleigh number (Ra), Hartmann number (Ha), volume fraction of nanoparticles (ϕ) and radiation parameter (Rd). Results showed that the heat transfer and the average Nusselt number increased for larger Rayleigh number and nanoparticle volume fractions. The heat transfer rate and velocity of the fluid decreased with increasing Ha. The minor vortex attached to the bottom of the cold block shrunk with larger Ra. However, the right vortex of the hot block increased for increasing Ha and Ra. For higher Rd, the flow velocity and heat transfer boosted up.