A Chebychev spectral elements approximation of the acoustic wave equation with first-order Clayton-Engquist-Majda absorbing boundary conditions was derived. Its discretization is based on spectral elements in space and central differences method in time. The numerical result
shows that this approximation has spectral accuracy in space and up to second-order in time. Compared with the same wave problems with conventional Dirichlet boundary conditions
the absorbing boundary conditions can reduce the numerical reflection on boundaries and avoid solution distortion. In addition
the central differences method is economic in memory requirement and computing time compared with implicit integral method.
关键词
Keywords
references
Alford R M, Kelly K R, Boore D M. Accuracy of finite-difference modeling of the acoustic wave equation[J].Geophysics,1974,39(4): 834-842.
Hughes T J R. The finite element method: linear static and dynamic finite element analysis[M]. New York, USA: Dover Publications Inc., 2000.
Patera A T. A spectral element method for fluid dynamics: laminar flow in a channel expansion[J]. Journal of Computational Physics, 1984, 54:468-488.
Clayton R, Engquist B. Absorbing boundary conditions for acoustic and elastic wave equations[J]. Bull Seism Soc Am, 1977, 67(6): 1527-1540.
Engquist B, Majda A. Absorbing boundary conditions for the numerical simulation of waves[J]. Mathematics of Computation, 1977,31(139):629-651.
Renaut R, Froehlich J. Pseudospectral Chebychev method for the 2D wave equation with domain stretching and absorbing boundary conditions[J]. Journal of Computational Physics, 1996,124:324-336.
Shao Xiumin, Liu Zhen.Stability analysis of explicit finite difference schemes for the acoustic wave equation with absorbing boundary conditions[J]. Mathematica Numerica Sinica, 2001, 23(2):163-186.