瞬变电磁场模拟中的CPML吸收边界条件

CPML Absorbing Boundary Condition in Modeling of Transient Electromagnetic Fields

提出用于瞬变电磁法(TEM)模拟的时域有限差分(FDTD)算法中的卷积完全匹配层(CPML)吸收边界条件.首先,在磁场散度方程显式处理条件下,计算磁场z分量时,构造出一种计算时域卷积项的方法,并详细推导计算磁场z分量的表达式.而后,对均匀半空间模型进行数值计算.结果表明,提出的CPML吸收边界条件在保证计算精度的前提下,实现了瞬变电磁法时域有限差分高效正演计算.

A scheme of convolutional perfectly matched layer（ CPML） absorbing boundary condition（ ABC） is proposed,which is used to truncate finite-difference time-domain（ FDTD） method modeling transient electromagnetic（ TEM） response. It derives specially CPML formulation dealing explicitly with divergence of magnetic induction and conceives an algorithm calculating convolutional term of z component. Then,the scheme is validated by numerical modeling of a homogeneous half-space model. The results indicate that efficient calculation of TEM is achieved.