Multi-Objective optimization of a novel swinging inlet strategy for Air-Cooled battery thermal management systems under Fast-Charging conditions in electrical vehicles

• Air-cooled BTMS using inclined and swinging inlet fans were examined by CFD analysis. • ANN modeling was used as surrogate functions for optimization. • Optimal inlet angle of fan established based on NSGA-II in a wide range of Reynolds numbers. • Minimized battery temperature, pack temperature difference and Pressure Drop were studied. • Best performing frequency of swinging fan inlet was found using optimal inlet angle. As electric vehicles continue to proliferate and pursue fast-charging performance that rivals traditional internal combustion engine refueling, thermal management challenges have escalated, making advancements in Battery Thermal Management System (BTMS) technology essential. This study conducted a comprehensive optimization-based investigation into inlet flow angles in an air-cooled BTMS and introduced a novel swinging inlet-fan cooling mechanism by numerically examining various inlet angles and Reynolds numbers, highlighting the significance of inlet angle on BTMS performance. The results indicate the presence of optimal initial variables that yield the most effective thermal management for the BTMS. A sensitivity analysis further reveals that the inlet angle as well as the Reynolds number exerts a major effect on the thermal efficiency. Artificial neural networks and multi-objective optimization using NSGA-II were employed to identify the optimal fixed-angle configurations for different Reynolds numbers. Accordingly, a dynamic swinging inlet-fan strategy that periodically varies the inlet angle was developed and assessed. The swinging inlet configuration demonstrated significantly superior thermal performance, achieving up to 12.6 % reductions in maximum temperature and temperature difference along with up to a 19 % reduction in pressure drop. The findings demonstrated that the swinging inlet-fan concept can significantly improve BTMS performance, offering a promising implication for the next generation of electric vehicles.