基于CFD的电动汽车驱动电机冷却流道对比研究

Comparative Study on Cooling Channel for Electric Vehicle Drive Motor Based on CFD

根据电动汽车驱动电机的冷却特点,提出了一种新型冷却结构:周向多螺旋结构,建立了机壳内部流体的流动与换热三维数值模型,应用CFD技术对机壳在不同水冷方案下的流场和温度场进行耦合计算.计算结果显示,周向"Z"字形流道结构的均温性和冷却效果良好,但压力损失较大,适用于电动汽车135 k W驱动电机在进口水温为65℃条件下的冷却,其最佳冷却水流量为9.8 L/min;周向多螺旋结构流道压阻小,可考虑用于更大功率密度的电机冷却.该研究为小体积、高功率密度的电机冷却设计及优化提供理论基础.

Based on the cooling characteristics of the electric vehicle drive motor,a novel cooling structure the circumferential multi spiral structure,was proposed. The three dimensional numerical model of fluid flow and heat transfer in the shell was established. The flow field and temperature field of different water cooling schemes were calculated based on CFD technology. The numerical results showed that the temperature uniformity and cooling performance of Circumferential ＂ Z＂ structure is better than the circumferential multi spiral structure; and the circumferential ＂ Z＂ structure was suitable for the cooling of 135 k W electric vehicle drive motor under the condition of inlet water temperature was 65 ℃,with the optimal water flow rate 9. 8 L/min.However,the circumferential multi spiral structure could be used for higher power density of the motor cooling for the better performance of pressure resistance. The research provided a theoretical basis for cooling design and optimization of the small size and high power density motor.