Thermal and acoustic optimization of guide pores in air-cooled charging modules serving electric vehicle batteries

High-power fast charging of electric vehicle (EV) battery energy storage systems relies on air-cooled charging modules operating at high rotational speeds, which generate aerodynamic noise. Since geometric changes affect noise, their trade-off with thermal performance must be addressed for thermoacoustic design. Unlike conventional porous liners or perforated heat-transfer fins, the guide pores act as downstream auxiliary outlets that regulate bypass flow and break down coherent vortices rather than absorb sound. This study quantifies how guide pore radius and horizontal distance shift this thermal-acoustic balance. To reduce aerodynamic noise and lower the maximum temperature, thereby improving charging availability and battery health, a coupled framework integrating an SST k - ω thermal model, large eddy simulation (LES), and the FW-H acoustic analogy was established. A surrogate-assisted bi-objective optimization approach was employed, in which OLHS sampling data were fed into Kriging models and the NSGA-II algorithm searched for the Pareto optimum. The optimal configuration has a pore spacing of 20.0 mm and a radius of 2.46 mm. Mechanistically, it disrupts large-scale coherent vortex structures and attenuates downstream shear layers. Quantitatively, the average overall sound pressure level was reduced by 1.19 dB(A), with a temperature decrease of 0.275 K. The Kriging surrogate showed relative errors below 0.4%. Properly positioned guide pores thus offer an effective solution to the heat-noise bottleneck in narrow ducts, suppressing tonal noise from periodic vortex shedding without compromising cooling capacity. These findings provide a design reference for thermal-acoustic co-optimization in high-power EV charging infrastructure, supporting safer and more durable battery energy storage under fast charging.