Multi-objective optimization of a U-shaped water jacket with a guide vane for improving the thermal performance of 20 kW in-wheel motor

Abstract

In-wheel motors (IWMs) are considered to replace centralized motors in electric vehicles due to a high efficiency. However, heat dissipation is a significant challenge in IWMs because of their limited space. In this study, a U-shaped water jacket with a guide vane design is newly proposed to improve the heat dissipation performance of IWMs. An IWM simulation model is developed and validated based on experimental data. Using six independent design variables, the multi-objective optimization is performed to maximize Q·V−1 while minimizing the pressure drop. The optimal design obtained from Pareto solutions indicates that the maximum coil temperature is reduced by 8.2 °C, while its lifespan increased by 83.9 % compared to the baseline. For the guide vane, the pressure drop is reduced by 26.7 %, while Q·V−1 is increased by 2.5 % compared to the initial design. The thickness of the guide vane and its distance from the end tip of the water jacket curved section, the two key design variables of the guide vane, have the most influential effect on Q·V−1 and pressure drop respectively. Finally, as the continuous rated power increases, the proposed design has a significant impact on the improved heat dissipation performance of the IWM.