ADI-FDTD在三维散射计算中的应用

基于交替方向隐式(ADI)技术的时域有限差分法(FDTD)是一种非条件稳定的计算方法,该方法的时间步长不受Courant稳定条件限制,而由数值色散误差决定.与传统的FDTD相比,ADI-FDTD增大了时间步长,缩短了总的计算时间.文中将该方法用于计算自由空间中三维目标的散射,给出了激励源以及总散场连接边界的设置.并将计算结果与FDTD结果对比,在具有同等精度的情况下,ADI-FDTD可大幅减少计算时间.

The Application of ADI-FDTD for Three-Dimensional Scattering

An implicit finite difference time domain method using the principle of alternating direction implicit technique is unconditionally stable, and the maximum time step size is not limited by the CFL condition, but rather by numerical errors. Compared with the conventional FDTD method, the time step size of ADI-FDTD can be much larger, so it takes less time to simulate. In this paper ADI-FDTD is applied to simulate the scattering of three-dimensional targets in vacuum and the settings of excitation and total-field/scattered-field connecting boundary condition are derived. Compared with FDTD, the results of ADI-FDTD have the same level of accuracy as conventional FDTD and the CPU cost is obviously reduced.