The Stretched-Mesh Huygens Absorbing Boundary Condition (SM-HABC)

The Huygens absorbing boundary condition (HABC) is a new implementation of the analytical ABCs which were in common use before the introduction of the perfectly matched layer (PML) ABC. In contrast to the traditional implementation, the HABC allows analytical ABCs to be combined easily with other ABCs. This opens the way to combinations of two ABCs where the advantages of both are preserved while their drawbacks are removed. This is the case with the stretched mesh HABC which relies on an analytical ABC for the absorption of traveling waves and a real stretch of coordinates for the absorption of evanescent waves. This paper demonstrates that such a combination can achieve a high absorption over the whole frequency spectrum and can challenge the PML ABC in wave-structure interaction problems.