A wave-based finite element analysis for acoustic transmission in fluid-filled elastic waveguides

• Published in: The Journal of the Acoustical Society of America Vol. 125; no. 4; p. 2053
• Main Author: Peplow, Andrew T
• Format: Journal Article
• Language: English
• Published: United States 01.04.2009
• ISSN: 1520-8524
• DOI: 10.1121/1.3087430

This paper describes an original numerical prediction technique developed for the analysis of coupled vibro-acoustic problems in fluid waveguides. Specifically it is a wave-based method that adopts a spectral element approach. Unlike the conventional element-based methods, this technique uses wave functions that satisfy the governing equations to describe the dynamic variables exactly. One advantage is that fine domain discretizations, used by element-based methods near the fluid-structure interface typically, are no longer required. Hence the resulting model sizes are much smaller than element-based methods yielding a more time-efficient prediction technique that may allow handling of mid-frequency applications. Another advantage is that dispersion relations between propagating and excitation wavenumbers are easily obtained, and an example to show this, as well as a discussion on how the wave-based prediction technique can be used for two coupled vibro-acoustic problems: a cavity with a non-reflecting boundary and a silencer duct problem, is presented. Its beneficial characteristics compared to element-based methods are demonstrated through the validation study and transmission loss examples.