Enhanced EV battery cooling using hybrid nanofluids in inclined mini-channels under magnetic field influence

Abstract

Effective thermal management in electric vehicle (EV) battery systems remains a critical challenge, especially under high-load operations where heat accumulation can impair performance and safety. Despite recent advancements, limited investigations have addressed the collective influence of channel inclination and magnetic field application on hybrid nanofluid-based cooling. This study numerically analyses this gap by exploring the thermo-hydraulic performance of a Fe3O4 + TiO2 hybrid nanofluid in inclined mini-channels under varying magnetic field conditions. A 2% volume fraction hybrid nanofluid flows through a 40 × 4 mm2 channel inclined from 0° to 90°, with external magnetic field strengths of 1000G, 1500G, and 2000G applied at four locations (X = 7.5 mm, 15 mm, 25 mm, and 32.5 mm). Simulations are performed across Reynolds numbers of 100, 150, 170, 190, 210, and 250. Key performance indicators such as Nusselt number, friction factor, Colburn j-factor and thermal enhancement factor (TEF) are evaluated. Results demonstrate a maximum enhancement in Nusselt number of 17.42% at 1000G, 20.89% at 1500G, and 40.31% at 2000G. Correspondingly, the friction factor increases by 30.72%, 26.34%, and 20.29% at 90° inclination for each respective field strength. Notably, TEF values remain consistently above unity (> 1) across all tested configurations, confirming net thermal performance gains. These findings confirm the viability of magnetically augmented hybrid nanofluid-based mini-channel cooling systems as a scalable, energy-efficient strategy for advanced EV battery thermal management. The presented framework offers a robust foundation for future experimental and computational advancements in high-performance battery cooling technologies.