Computational investigation of heat transfer and fluid flow in a NEPCM-filled cavity with sinusoidal porous layer: Influence of magnetic field and exothermic reactions

This pioneering study presents a novel investigation of the complex interplay of magnetohydrodynamic (MHD) free convection, double-diffusion, and exothermic reactions in a square cavity with a unique configuration. A corrugated porous layer with a thickness of 0.2L adheres to the left wall. The cavity is partially filled with a nano-enhanced phase change material (NEPCM) suspended porous medium. This innovative design combines the benefits of corrugated surfaces, NEPCMs, and magnetic field control for enhanced thermal management. Using the Galerkin finite element method and PARDISO solver, a comprehensive numerical analysis investigates the effects of various parameters on heat transfer, mass transfer, and entropy generation. These parameters include Frank-Kameneteskii number ( ), Darcy number ( ), Rayleigh number ( ), buoyancy ratio ( ), Lewis number ( ), fusion temperature ( ), Stefan number ( ), magnetic field inclination ( ), Hartmann number ( ), and NEPCM concentration ( ). Results demonstrate that increasing Ra from to enhances the average Nusselt number by 324% at . Nanoparticle volume fraction significantly improves heat transfer, with a 67.6% increase in Nusselt number as rises from 0.01 to 0.035. The magnetic field suppresses convection, reducing Nusselt and Sherwood numbers by 57.8% and 27.4%, respectively, as increases from 0 to 50. Entropy generation decreases by 84% under the same conditions. These findings are particularly relevant for designing advanced heat exchangers, solar thermal systems, and electronic cooling applications, where precise control of heat transfer and thermal energy storage is crucial.