波动方程时域有限差分法的一种新激励源

A New Exciting Source for the Wave-equation Finite-difference Time-domain Method

鉴于目前现有激励源技术存在的一些不足,通过理论分析,发现时域有限差分法(FDTD)的"总场-散射场源"可用于波动方程时域有限差分法(WEFDTD),但实现方法不同.WEFDTD的具体方法是将仿真区域划分为总场区和散射场区,激励源设置在两区域的分界面上,并将两区域分界面上的差分格式作出一些修改.该技术能有效地克服WEFDTD已有激励源的不足.也进行了相关的编程数值实验以验证该技术的有效性,模拟方式为简谐波和高斯脉冲的传播过程,最终的实验表明计算结果能与解析解很好地吻合.

The exciting source technologies of wave-equation finite-difference time-domain method（WEFDTD） have been identified with some significant defects.Based on analysis conducted in this work,it is found that the ＂TF-SF＂ source of the finite-difference time-domain method（FDTD） can also be used in WEFDTD,but the implementation is different from FDTD.The implementing method in WEFDTD can be described as follow： divide the computational region into total field region and scattering field region;set the exciting source on the boundaries of the 2 regions;make some modifications to the difference equations on the 2 region boundaries.The exciting source can eliminate the defects of the other sources of the WEFDTD.To test the validity of the exciting source,numerical experiments are carried out,the radiations of a harmonic wave and a Gauss impulse are simulated using experimental data.The calculated results are found to be in good agreement with the analytic results.