Orthogonal Optimization and Numerical Simulation Study of Battery Module Thermal Management System Based on S-Shaped Side-Cooling Structure

Abstract This study systematically investigates an optimized S-shaped side-cooling structure to address the challenges of limited heat dissipation efficiency and temperature field inhomogeneity in lithium iron phosphate (LiFePO4) battery modules under conventional bottom cooling configurations. A three-dimensional computational model was established to examine the influence patterns of cooling structure, coolant mass flowrate, inlet temperature, flow channel inlet width, and flow channel inlet length on the thermal performance of battery modules. Orthogonal experimental design methodology was employed to conduct parameter optimization under constrained conditions of inlet temperature (25 °C) and S-shaped side-cooling structure, with a focus on mass flowrate, flow channel inlet width, and flow channel inlet length. The simulation results reveal that optimal thermal management performance is achieved at a mass flowrate of 0.15 kg/s, a flow channel inlet length of 50 mm, and a flow channel inlet width of 4 mm. Compared with conventional bottom cooling, the temperature difference of the battery is reduced by 59.20%, and the differential pressure of the flow channel is 1.44 kPa. The research establishes theoretical foundations and provides an optimization paradigm for thermal management design in high-energy-density battery systems.