辛差分格式的Mur吸收边界在电磁场计算中的应用

Application of Mur Absorbing Boundary Conditions Based on Symplectic Difference Scheme in the Computations of Electromagnetic Fields

基于辛(symplectic)差分格式的时域有限差分(FDTD)法,将辛分块Runge-Kutta(SPRK)法引入Mur吸收边界条件(ABC)的推导过程,用辛差分格式代替原来的中心差分格式离散时间变量,推导出了基于辛差分格式的Mur吸收边界条件。通过将辛格式的Mur吸收边界结合辛时域有限差分法,对典型算例进行数值模拟,并将计算效果与传统Mur边界结合时域有限差分法的效果比较,表明辛格式的Mur吸收边界结合辛时域有限差分法计算效果良好,基于辛差分格式的Mur吸收边界条件是正确、有效的,计算精度优于传统方法。

Successful applications of the symplectic difference scheme to the Mur absorbing boundary condition （ABC） are demonstrated. A special difference scheme based on symplectic partitioned RungeKutta method is used to discrete the time variables in the Mur absorbing boundary conditions. Numerical simulations demonstrate that the symplectic Mur ABC is very effective, and the symplectic finite difference time-domain （SFDTD） combined with this absorbing boundary condition works better than the FDTD based on the conventional Mur ABC.