Purpose The purpose of this study is to explore how geometry, magnetic field and nanofluid composition affect the thermal performance and irreversibility of an electroconductive hybrid nanofluid inside a wavy inverted T-shaped chamber with a cold T-shaped fin. Design/methodology/approach The governing momentum and energy transport equations are solved using the finite-difference method under appropriate initial and boundary conditions. Key dimensionless parameters, including the Rayleigh number, Hartmann number, baffle length and nanoparticle volume fraction, are systematically varied. Two different base fluids, water and kerosene, are considered to examine their comparative effects. Findings The findings reveal that the presence of wavy cavity walls and the T-shaped baffle substantially modifies circulation patterns, enhancing convective transport. The kerosene-based hybrid nanofluid demonstrates superior thermal efficiency compared with the water-based counterpart. The study further highlights the interplay between magnetic field strength, nanoparticle concentration and geometric modification in governing heat transfer, entropy generation and ecological performance. Originality/value The originality of this research lies in uncovering how geometry, magnetic field and hybrid nanofluids work together to enhance heat transfer in complex enclosures. These findings provide practical guidance for the design of next-generation cooling and thermal management systems that achieve greater efficiency while minimizing irreversibility.
Soren et al. (2026) studied this question.