An Optimized CFS-PML for Wave–Structure Interaction Problems

The complex frequency-shifted perfectly matched layer (CFS-PML) is optimized for the finite-difference time-domain (FDTD) solution of wave-structure interaction problems. This mainly consists of optimizing the α parameter of the stretching coefficient of the PML in function of the frequency content of the problem to be solved. The resulting CFS-PML is only a few FDTD cells in thickness and can be placed 2 cells from the structure of interest. This renders the computational cost of the simulation of free space small in comparison with the overall cost of the FDTD calculation.