A modified form of Liao´s absorbing boundary condition

A new absorbing boundary condition (ABC) is described which modifies the ABC of Z.P. Liao et al. (1984) to provide better absorption of obliquely incident waves. The proposed modification of Liao´s ABC produces acceptably small reflections (e.g., <1%) over a much wider range of incidence angles. The new boundary condition can easily be tailored to absorb one or more specific incidence angles or wave speeds. This could be especially beneficial in problems involving layered media or elastic waves, where there are multiple wave speeds at the boundary. Furthermore, the condition is easy to implement, even at the corners of a computational box.<>