弱导电薄层介质材料电磁耦合等效计算方法研究

Research on equivalent calculation method for electromagnetic coupling of weakly conducting thin layer dielectric materials

面向核电磁脉冲等强电磁环境下复合材料壳体平台的电磁环境效应分析需求,根据Maxwell-Ampere定理的积分形式,分析得到了时域有限差分方法在处理弱导电薄层介质材料参数时的等效计算方法,即当介质等效波长远大于模型厚度时,可将薄层模型适当增厚,同时等比例减小其电导率,参数等效前后模型的电磁耦合特性基本相同。该方法通过等效增厚薄层材料从而实现增大空间离散步长,减少网格量的目的,不需要改变传统时域有限差分方法的时间步进格式,不会破坏计算的稳定性。无限大有耗介质薄板、薄层球体、含薄层壳体无人机电磁耦合等算例表明,在包含毫米级厚度弱导电介质薄层壳体平台的核电磁脉冲耦合模拟中,该方法具有较好的适用性。

To analyze the electromagnetic environmental effects of composite shell platforms in strong electromagnetic environments such as nuclear electromagnetic pulses,we have obtained an equivalent calculation method of the finite-difference time-domain method in dealing with weakly conducting thin-layer dielectric materials based on the integral form of the Maxwell-Amper theorem.The thin layer model can be appropriately thickened while proportionally reducing its conductivity when the equivalent wavelength of the medium is larger than the model thickness.The electromagnetic coupling characteristics of the model before and after parameter equivalence are essentially the same.This method can reduce the computational effort by increasing the grid step size.In addition,this method does not require changing the time step format of the traditional finite-difference time-domain method and does not affect the stability of the calculation.Numerical experiments,such as the examples using infinitely large thin plates,thin spherical layers,and electromagnetic coupling of unmanned aerial vehicles with thin shells,have shown that it has good applicability to the electromagnetic coupling simulation of thin-shell platforms containing weakly conducting materials with millimeter thickness in nuclear electromagnetic pulse environments.