组合网格法在电磁-机械耦合问题中的应用

将组合网格法应用于电磁-机械耦合问题的分析，用粗网格剖分空气及源电流区，用细网格剖分运动导体区。该方法克服了常规一套有限元网格计算该类问题时需要网格重剖的麻烦。讨论了组合网格法的算法实施具体步骤，粗细网格间采用有限元方法反复迭代计算，粗网格的计算值通过插值矩阵映射到细网格的边界上，之后粗网格的场量通过细网格上计算的余量进行校正。指出由于网格不匹配产生的非协调误差和误差减小方法。在每一时间步，不需重新剖分而只需修改细网格的节点坐标值即可实现导体的运动。计算结果与TEAM标准问题28的实验结果进行比较得到了较好的一致性，验证了算法在处理该类问题时的有效性。

Application of Composite Grid Method in the Electromagnetic-mechanical Coupled Problem

Composite grid method (CGM) is applied in analysis of electromagnetic-mechanical coupled problem. The region of air and current source is discretized with coarse grid, and region of moving conductor is discretized with fine grid. The difficulty of remeshing in normal finite element technique based on one set of grid is overcomed in CGM. The detailed procedure of implementing the algorithm of CGM is discussed. Equations on coarse and fine grids are solved iteratively by finite element method. Calculated results in coarse grid are mapped into boundary of fine grid through interpolation matrix. Then those results in coarse grid are corrected by residuals calculated in fine grid. The non-conforming error is introduced in case of non-matching of two grids. The method to reduce such error is introduced. At each time step, instead of remeshing the whole model it is only necessary to change coordinates of fine grid nodes. Numerical results obtained are compared with experimental data of TEAM Workshop Problem 28. Reasonable agreement is achieved and efficiency of CGM for such kind of problem was displayed.