面向电磁装置磁-热耦合分析的异型网格映射方法

Non-Matching Meshes Mapping Method in Coupled Magnetic and Thermal Analysis of Electromagnetic Devices

采用弱耦合有限元法求解电磁装置中的电磁场、流场和温度场的耦合问题时,电磁场计算得到的能量损耗要通过网格传递到温度场作为载荷,结合空气或液体的散热进行热分析。由于电磁场和热-流场在求解时对网格离散要求相差很大,因此若要兼顾各种场的要求需剖分成统一的有限元模型,势必会造成网格单元数很大、提高计算代价。而如果采用不同的网格模型,则无法实现网格间的数据直接映射。提出一种异型网格映射法,通过高斯积分及坐标变化来实现不同场之间不同网格的数据映射。此外,还提出了该方法的精度控制策略及误差修正系数,以保证计算结果的准确性。将异型网格映射法应用于文献中空气绝缘三相母线槽热分析中,将计算结果与常规同型网格直接映射方法及实验结果进行对比,进一步验证了该方法的有效性。

In the coupled electromagnetic fluid-dynam ical and thermal simulations which are done by the weakcoupling finite element method （ FEM ） for the electromagnetic devices, the thermal loads obtained from the energylosses by electromagnetic calculations are transferred between meshes to calculate the temperature distributions byconsidering the influence of air and flu id flow. Because the requirements of the meshes discretization scheme are quitedifferent between electromagnetic and fluid-therm al fields, the same finite element model applied to analyze bothrequirements w ill lead to increase the number of meshes and the time of calculation. However, i f different finiteelement models are used, the data cannot be directly transferred between the corresponding meshes. In this paper, anon-matching mesh mapping method is proposed. The energy losses can be transferred between the different meshes bythe Gauss integral and coordinate transformatioru Moreover, the strategy of precision control and error correctioncoefficient are proposed to ensure the calculation accuracy. This method is applied to an air insulation bus duct systemin the literature. The calculation results are compared with the normal matching meshes mapping method and theexperiment results to validate the proposed non-matching meshes mapping method.