Heat Source/Sink Effects on a Hybrid Nanofluid-Filled Porous Cavity

Magnetohydrodynamic natural convection flow and heat transfer in a square porous cavity differentially heated and cooled by heat source and sink, respectively, and filled with the Cu-Al2O3-water hybrid nanofluid is studied numerically. The active parts of the left and the right side walls of the cavity are maintained at cooled temperature, and the active parts of the top and bottom walls are maintained at hot temperature. The enclosure's inactive parts of its side walls are kept insulated. The governing equations in the two-dimensional space are discretized using finite difference methodology. A proper upwinding scheme is employed to obtain stabilized solutions. Using the developed code, a parametric study is undertaken, and the effects of the Rayleigh number, the locations of the active parts of the side walls, and the volume fraction of the nanoparticles on the fluid flow and heat transfer inside the cavity are investigated. It is observed from the results that the average Nusselt number decreases substantially for hybrid suspension when the location of the heat source D changes. It is noted that the velocity decreases in magnitude when Hartmann number Ha increases. The local Nusselt number gets enhanced for the hybrid suspension as the nanoparticle volume fraction phi increases. It is also shown that, as compared to Cu and Al2O3, the hybrid suspension has lower magnitude of average Nusselt number.