Numerical analysis of MHD nanofluid flow and heat transfer in a circular porous medium containing a Cassini oval under the influence of the Lorentz and buoyancy forces

This paper reports our study on the flow characteristics and heat transfer performance of magnetohydrodynamics (MHD) nanofluid in an innovative porous, circle-shaped enclosure incorporating a Cassini oval cavity using the Darcy law. The MHD nanofluid considered in this study is Al2O3-H2O. A two-dimensional (2D) mathematical model is developed based on a homogeneous model. The formulation of the vorticity stream function is then used to obtain coupled equations. Finally, the coupled partial differential equations are solved numerically using the finite element method. Model predictions are then compared against results from the previously published study to verify the accuracy and validity of the developed model, and a good agreement is achieved. Figures demonstrate the effects of nanoparticle volume fraction, inclined angle, Lorentz, and buoyancy forces on the MHD nanofluid flow. The results indicate that the convection mechanism becomes weaker with an increase in solid nanoparticle volume fraction. A significant increase in the Rayleigh number will lead to a stronger and more cohesive core vortex. In addition, when magnetic force is applied horizontally, favorable Nuave occurs. Based on the numerical results, a correlation to predict the average Nusselt number within the enclosure is developed as a function of Hartmann number (H alpha) Rayleigh number (R alpha), and inclined angle (gamma).