Orthogonality relations for fluid-structural waves in a three-dimensional, rectangular duct with flexible walls

Autor: J. B. Lawrie
Rok vydání: 2009
Předmět:
Zdroj: Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences. 465:2347-2367
ISSN: 1471-2946
1364-5021
DOI: 10.1098/rspa.2009.0066
Popis: An exact expression for the fluid-coupled structural waves that propagate in a three-dimensional, rectangular waveguide with elastic walls is presented in terms of the non-separable eigenfunctions ψ n ( y , z ). It is proved that these eigenfunctions are linearly dependent and that an eigenfunction expansion representation of a suitably smooth function f ( y , z ) converges point-wise to that function. Orthogonality results for the derivatives ψ n y ( a , z ) are derived which, together with a partial orthogonality relation for ψ n ( y , z ), enable the solution of a wide range of acoustic scattering problems. Two prototype problems, of the type typically encountered in two-part scattering problems, are solved, and numerical results showing the displacement of the elastic walls are presented.
Databáze: OpenAIRE