柱坐标系中的驻波—行波边界条件

Standing-Traveling Wave Boundary Condition For FDTD Simulation in Cylindrical Coordinates

时域有限差分法模拟中所用的驻波—行波边界条件(STWBC)具有较高的计算效率,且非常易于实现。但此吸收边界条件最初仅用于直角坐标的情形。文章将STWBC扩展到柱坐标的情形与直角坐标的情形一样,柱坐标中的STWBC也在计算域外附加理想导电(磁)壁进行截断,并将边界处的驻波转化为行波,从而模拟行波在无限大空间的传播。文中给出的数值算例证明了此种吸收边界条件的有效性。

Standing-Traveling Wave Boundary Condition （STWBC） used in Finite-Difference Time-Domain （FDTD） simulations is computationally efficient and very easy to implement. But, the initial implementation is restricted to Cartesian coordinates. In this paper, STWBC is extended in cylindrical coordinates. The perfect electric conducting （PEC） is used in the extension, and the standing wave on the boundary is transformed to the traveling wave. A Numerical example is given to validate this implementation.