Magnetohydrodynamics Mixed Convection Effects on Hybrid Nanofluid Heat Transfer and Entropy Generation

This study delves into the dynamics of magnetohydrodynamics within a mixed convective hydrothermal environment while exploring entropy generation. Specifically, it investigates these phenomena within a corrugated enclosure containing a hybrid nanofluid comprising MoS2, SiO2, and water. Two isothermal heaters protrude from both ends of the bottom of the enclosure, while a cold protrusion is situated at the center of the bottom. A higher-order compact finite difference approach is utilized to solve the dimensionless governing equations. Numerical validations are performed to demonstrate the accuracy of the mathematical model. The computational investigation is conducted across a range of parameters, including Richardson number (Ri=0.01-100), aspect ratios of protruding heater length with cold geometry length (AR=0.2,0.4,0.6,0.8), nanoparticle volume percentage (phi=0%-4%), and Hartmann number (Ha=0-120). The Reynolds number is maintained constant at Re=100. The results of the numerical simulations are presented through visual representations such as isotherms, streamlines, and entropy generation contours. Furthermore, the average Nusselt number and overall entropy formation are analyzed. The findings suggest that as natural convection effects become more dominant, the significance of increasing the aspect ratio becomes apparent. Particularly, at the highest aspect ratio (AR) of 0.8, a considerable enhancement in heat transfer of 279.36% is observed by increasing the Richardson number from 0.01 to 100 for a nanoparticle volume fraction (phi) of 4%, without considering the magnetic field effect. However, this enhanced heat transfer diminishes by 7.12% when magnetic field strength (Ha) is set to 40. Moreover, as the aspect ratio decreases from 0.8 to 0.2, there is a noticeable reduction in total entropy generation, amounting to a decrease of 48.01%.