Wave operators and asymptotic solutions of wave propagation problems of classical physics

1966 ◽  
Vol 22 (1) ◽  
pp. 37-76 ◽  
Author(s):  
Calvin H. Wilcox

1971 ◽  
Vol 77 (5) ◽  
pp. 777-783 ◽  
Author(s):  
John R. Schulenberger ◽  
Calvin H. Wilcox


2008 ◽  
Vol 16 (04) ◽  
pp. 531-561 ◽  
Author(s):  
GÉZA SERIANI ◽  
SAULO POMPONET OLIVEIRA

Spectral element methods are now widely used for wave propagation simulations. They are appreciated for their high order of accuracy, but are still used on a heuristic basis. In this work we present the numerical dispersion of spectral elements, which allows us to assess their error limits and to devise efficient numerical simulations, particularly for 2D and 3D problems. We propose a novel approach based on a discrete Fourier transform of both the probing plane waves and the discrete wave operators. The underlying dispersion relation is estimated by the Rayleigh quotients of the plane waves with respect to the discrete operator. Together with the Kronecker product properties, this approach delivers numerical dispersion estimates for 1D operators as well as for 2D and 3D operators, and is well suited for spectral element methods, which use nonequidistant collocation points such as Gauss–Lobatto–Chebyshev and Gauss–Lobatto–Legendre points. We illustrate this methodology with dispersion and anisotropy graphs for spectral elements with polynomial degrees from 4 to 12. These graphs confirm the rule of thumb that spectral element methods reach a safe level of accuracy at about four grid points per wavelength.



Author(s):  
Arthur D. Gorman

An approximate wave equation that models scalar wave propagation in a moving fluid whose ambient properties and flow are inhomogeneous both in space and time is considered. Asymptotic solutions for both non–caustic and caustic regions and some Hamiltonian properties of the equation in both non–caustic and caustic regions are developed.







2004 ◽  
Vol 70 (6) ◽  
Author(s):  
O. Bernus ◽  
M. Wellner ◽  
A. M. Pertsov


1993 ◽  
Vol 113 (2) ◽  
pp. 423-447 ◽  
Author(s):  
G. F. Roach ◽  
Bo Zhang

AbstractIn this paper, we establish the generalized eigenfunction expansions for wave propagation in inhomogeneous, penetrable media in ℝn(n ≥ 2) with an unbounded interface. We then use them together with the method of stationary phase to prove the existence of the wave operators and to obtain the representations of the wave operators in terms of the generalized Fourier transforms.



1973 ◽  
Vol 3 (1) ◽  
pp. 57-77 ◽  
Author(s):  
James A. La vita ◽  
John R. Schulenberger ◽  
Calvin H. Wilcox


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