基于E,H为变量点匹配时域有限元法计算点源的问题及改进

Shortcoming of point-matched time domain finite element method in solving radiation problem with point source by E H formulation and improved methods

点匹配时域有限元方法,是继时域有限差分方法后,又一重要的电磁场时域数值分析方法。在应用该方法计算点源的散射场时,发现这种方法的缺陷,每两个相邻节点上的电场强度(或磁场强度)计算结果不连续。对于点匹配时域有限元法的上述缺陷,给出理论上的解释。对于二维问题,给出了改进的方法,克服了点匹配时域有限元法电场强度(或磁场强度)计算结果不连续的缺陷,计算结果与时域有限差分方法或解析结果吻合。

Point-matched time domain finite element method is one of the important approaches for transient electromagnetic fields computation except finite difference time domain method. The author found the shortooming in the method mentioned above which was referenced by many other authors. The electric and magnetic fields on two adjacent nodes are not continuous in calculations by above method. It is presented that the explanation, based on the electromagnetics, for causing the shortcoming in point-matched time domain finite element method in this paper. At last two modified approaches to overcome the problems are presented in this paper. The improved methods eliminate the numerical errors, and the calculated results are in good agreement with the standard FDTD method and the analytic ones.