Entropy optimization and heat transfer analysis of radiative MHD hybrid nanofluid flow in a porous triangular cavity under varying thermal effects

• Galerkin Finite Element Method was used to investigate MHD natural convection of Ag–Cu/EG hybrid nanofluid in a porous triangular cavity with radiation effects. • Analyzed the influence of uniform, sinusoidal, and step heating on heat transfer and entropy generation. • Found that sinusoidal heating produced minimum total entropy and enhances thermal uniformity. • Uniform heating produces high convection which increases overall heat transfer. • Non-uniform heating exhibits a weak sensitivity of heat transfer to increasing Rayleigh number. This study examines the entropy formation of magnetohydrodynamics (MHD) natural convection flow in a radiative porous right-angled triangular cavity filled with a hybrid nanofluid under uniform and non-uniform(sinusoidal and step) heating conditions. The hybrid nanofluid is made up of copper and silver nanoparticles dispersed in ethylene glycol, which serves as the base fluid. Using MATHEMATICA, the study investigates various volume fraction of nanoparticle ( ϕ ), Radiation parameter (R), Darcy (Da), Rayleigh (Ra) and Hartmann numbers (Ha) to analyze the flow motion, heat transfer and entropy formation. The standard Galerkin finite element method is used to solve the governing system of PDEs. Code validation revealed a high degree of concordance with previously published findings. Numerical simulations indicate that rising Ha suppresses convection and increases entropy via magnetic dissipation, whereas higher R enhance flow and heat transfer. Circulation intensifies with increasing porous permeability, promoting stronger convective mixing. Uniform heating yields the highest heat transfer, with average Nusselt number increased by 56% (Ha = 0) as Ra rises from 10 4 to 10 6 . In contrast, sinusoidal and step heating lead to reductions in heat transfer, with heat transfer rate decreased by 16% and 9%, respectively, over the same Ra range, indicating that non-uniform heating exhibit a weak sensitivity of heat transfer to increasing Rayleigh number. Sinusoidal heating results in very low entropy generation, indicating more efficient thermal performance. This study explores the understanding of heat transfer and entropy generation in porous cavities, offering insights for efficient thermal management in solar, electronic, and thermal storage systems.