Significance of activation energy on Jeffrey–Hamel MHD hybrid nanofluid flow inside a converging-diverging channel with non-Darcy stretching and shrinking effects

Enhancing heat transfer efficiency and understanding fluid flow behavior in convergent–divergent channels remain significant challenges in advanced thermal engineering applications. This study presents a novel numerical investigation of magnetohydrodynamic (MHD) Jeffrey–Hamel flow through a porous medium in convergent and divergent channels by simultaneously incorporating Joule heating, thermal radiation, activation energy, and stretching/shrinking wall effects in the presence of hybrid nanofluids—an aspect not previously addressed in a unified framework. Three different hybrid nanofluids are considered to evaluate their comparative thermal performance. The governing equations are solved using the bvp5c method. The influences of key physical parameters, including the magnetic parameter, inertia parameter, porosity parameter, stretching/shrinking parameter, and channel angle, on the velocity distribution are examined. Additionally, the effects of the magnetic parameter, Eckert number, thermal radiation, and heat source strength on the temperature field are analyzed, along with the role of activation energy on the concentration profile. The results reveal that the combined effects of magnetic field and inertia significantly enhance the skin-friction coefficient. Heat transfer is intensified with increasing magnetic parameter and heat source strength, as reflected by higher Nusselt numbers, while mass transfer is enhanced with increasing magnetic parameter and decreasing activation energy. Among the hybrid nanofluids studied, the MoS2-Al2O3 water hybrid nanofluid exhibits the highest heat transfer efficiency, highlighting its potential for advanced MHD-based thermal systems.