High order accuracy is of great significance for computational aero-acoustics(CAA). On the basis of the high order accuracy of the infinite smooth interpolation function adopted in the spectral elements method
a Chebychev spectral elements approximation for the acoustic propagation problem in the subsonic uniform mean flow is applied in this study. In this approach
the discretization is based on spectral elements in space with first-order Clayton-Engquist-Majda absorbing boundary conditions and the implicit Newmark method in time marching. The numerical results with sixth-order spectral accuracy in space and up to second-order in time agree well with the analytical solutions. The Newmark method in time with less computing resource consumption also has the advantages of stability. The higher order spectral approximation can be employed to further enhance the accuracy and higher order absorbing boundary conditions might be applied to improve the spectral element approach.
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