This study aims to investigate entropy generation and transport characteristics of magnetohydrodynamic double-diffusive natural convection in a porous convex circular enclosure filled with an Al2O3–CuO–Ag/water ternary hybrid nanofluid, with emphasis on the combined effects of buoyancy, magnetic field, permeability, radiation and nanoparticle loading.
A mathematical model based on the Boussinesq approximation is formulated and transformed into dimensionless form. The governing equations are solved numerically using a Galerkin finite element method. The computational model is validated through grid independence and benchmark comparisons.
The results reveal that increasing the Rayleigh number (Ra) significantly enhances buoyancy-driven convection, leading to more than a 300% increase in kinetic energy and approximately 140% enhancement in Sherwood number. Increasing the Darcy number (Da) improves permeability and raises viscous and total entropy generation by about 85%–90%. In contrast, increasing the Hartmann number (Ha) introduces Lorentz-force-induced magnetic damping, reducing viscous and total entropy by approximately 55%–60% and 23%, respectively, despite a significant increase in magnetic entropy. Furthermore, higher buoyancy ratio, radiation parameter and Lewis number intensify entropy generation, whereas increasing nanoparticle concentration suppresses flow intensity and reduces overall entropy generation.
This study provides a comprehensive analysis of thermosolutal convection incorporating magnetohydrodynamic effects, porous resistance, radiation and ternary hybrid nanofluid interactions within a circular finned enclosure. It offers new insights into entropy generation mechanisms and the competing roles of buoyancy, magnetic damping and diffusive transport, which are not fully explored in existing studies.
