Hybrid absorbing boundary conditions of PML and CRBC
A hybrid absorbing boundary condition (HABC) is developed for time-harmonic wave scattering problems by combining the perfectly matched layers (PML) and complete radiation boundary conditions (CRBC). A model problem governed by the Helmholtz equation is considered, in which solutions propagate in one direction, describing wave phenomena arising in guided structures or periodic diffraction gratings. Since the solutions can be represented as a superposition of a finite number of propagating modes and an infinite number of evanescent modes, appropriate absorbing boundary conditions are required to handle both types of modes efficiently. The well-posedness of the model problem is discussed supplemented with HABC and the convergence of approximate solutions. The choice of the CRBC parameters is investigated to minimize the reflection error for a given number of grid points along the direction of wave propagation Numerical experiments are presented illustrating the performance of HABC.
scientific article; zbMATH DE number 7389251