Design and Simulation of Thermal Management for Direct-Cooled Batteries Using L-Shaped Twisted Fins

A thermal management system for cylindrical lithium-ion battery packs, based on L-shaped twisted fins, is proposed to address the heat dissipation challenges. Numerical simulations were conducted to analyze and optimize its thermal performance. The system employs aluminum fins in direct contact with the coolant to enhance heat transfer and cooling efficiency. A three-dimensional steady-state heat transfer model was developed, coupled with fluid-structure simulations, to evaluate the influence of various fin geometries (quantity, length) and coolant flow rate on the system’s thermal performance. The results indicate that the optimal number of fins is 4, the optimal fin length is 2 mm, and the best inlet flow rate is $0.1 \mathrm{~m} / \mathrm{s}$. The optimized fin design significantly reduces the maximum temperature of the battery pack, with a $2.7^{\circ} \mathrm{C}$ (7.9%) reduction in the maximum surface temperature, while improving temperature uniformity, with the maximum temperature difference decreasing from $7.64^{\circ} \mathrm{C}$ to $4.05^{\circ} \mathrm{C}$ (a $46.99 \%$ reduction). Additionally, the energy consumption remains within acceptable limits. These findings provide a theoretical foundation for the design of efficient and lightweight thermal management systems for battery packs.