动磁式作动器电-磁-热-流耦合数值模拟

Numerical simulation of electric-magnetic-thermal-flow coupling of dynamic magnetic actuators

以二自由度动磁式作动器为研究对象,提出基于Maxwell与Icepak的电磁场、温度场、流体场耦合传递方法。将电磁场中的涡流损耗和铜耗映射到温度场,采用强制液冷对作动器进行散热设计,并与自然冷却的温升进行对比。分析冷却液流速对散热的影响规律,利用管内强制对流Dittus-Boelter关联式与数值模拟结果进行对比验证。结果表明,20℃环境下,自然对流散热和液冷强制对流散热的作动器的最高温度分别为137℃和22℃,液冷散热的温升仅为自然对流散热的20%,液冷散热热平衡时间缩短40%;对作动器温升实现有效抑制;冷却液最佳流速选择在1.6 m/s~1.8 m/s,在此范围内达到温升饱和区;冷却液在雷诺数5 000~11 000的湍流状态下,数值模拟结果与Dittus-Boelter关联式偏差控制在5%—10%,验证了数值模拟结果的正确性。

A two-degree-of-freedom maglev actuator was used as the research object, the coupled transfer method of electromagnetic, temperature and flow fields based on Maxwell and Icepak was proposed. The eddy current loss and copper consumption in the electromagnetic field were mapped to the temperature field, then forced liquid cooling was used for heat dissipation design of the actuator and the temperature rise was compared with natural cooling. The influence of coolant flow rate on heat dissipation was analyzed, and the Dittus-Boelter correlation was compared with the numerical simulation results for verification. The results show that the maximum temperatures of the actuator with natural convection cooling and liquid-cooled forced convection cooling are 137 °C and 22 °C, respectively, at 20 °C. The temperature rise of liquid-cooled cooling is only 20% of that of natural convection cooling, and the thermal equilibrium time of liquid-cooled cooling is shortened by 40%. The optimal coolant flow rate is selected from 1.6 m/s to 1.8 m/s, and the saturation zone of temperature rise is reached in this range;the deviation of the numerical simulation results from the Dittus-Boelter correlation is controlled at 5%-10% under the turbulent flow condition of Reynolds number 5000-11000, which verifies the correctness of the numerical simulation results.