ABSTRACT This study investigates free convection of energy and flow behavior within a C‐shaped wavy porous cavity containing Al 2 O 3 –Cu/H 2 O hybrid nanofluid, while accounting for the effects of an inclined magnetic field and an internal heat source/sink. The model utilizes a local thermal non‐equilibrium (LTNE) strategy to precisely represent the interaction between the nanofluid and the solid matrix. The dimensionless governing equations are resolved via the finite difference approach within a MATLAB setup. A comprehensive parametric study is conducted by altering the Rayleigh number, Hartmann number, Darcy number, porosity, cavity shape, nanoparticle volume percentage, and thermal source/sink intensity in both two‐dimensional and three‐dimensional domains. The findings demonstrate that increasing the Rayleigh number enhances convective flow and improves thermal transfer within the cavity. When fluid velocity is suppressed by strong magnetic fields, the system transitions to conduction‐dominated thermal transfer. The integration of Al 2 O 3 –Cu hybrid nanofluid markedly enhances heat transmission owing to its exceptional thermal conductivity. Alterations in cavity geometry and heater length affect vortex formation, streamline circulation, and localized heat transfer rates. The average heat transfer results validate the thermal efficiency of hybrid nanofluids in enhancing free convection. These insights enhance the design of passive cooling systems for applications in electronic cooling, thermal insulation, and energy system optimization. An increase in the Darcy number indicates higher permeability of the porous medium, which enhances fluid flow and consequently improves heat transfer efficiency.
Nabwey et al. (Fri,) studied this question.