Analysis of reflection characteristics of a normal incidence plane wave on resonant sound absorbers: A finite element approach

Easwaran, V and Munjal, ML (1993) Analysis of reflection characteristics of a normal incidence plane wave on resonant sound absorbers: A finite element approach. In: Journal of the Acoustical Society of America, 93 (3). pp. 1308-1318.

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Abstract

Resonant sound absorbers are used widely as anechoic coatings in underwater applications. In this paper a finite element scheme based on the Galerkin technique is used to analyze the reflection characteristics of the resonant absorber when insonified by a normal incidence plane wave. A waveguide theory coupled with an impedance matching condition in the fluid is used to model the problem. It is shown in this paper that the fluid medium encompassing the absorber can be modeled as an elastic medium with equivalent Lamé constants. Quarter symmetry conditions within the periodic unit cell are exploited. The finite element results are compared with analytical results, and with results published elsewhere in the literature. It is shown in the process that meshing of the fluid domain can be obviated if the transmission coefficients or reflection coefficients only are desired as is often the case. Finally, some design curves for thin resonant absorbers with water closure are presented in this paper.

Item Type:	Journal Article
Publication:	Journal of the Acoustical Society of America
Publisher:	American Institute of Physics
Additional Information:	Copyright of this article belongs to American Institute of Physics.
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	31 Jan 2011 12:03
Last Modified:	31 Jan 2011 12:03
URI:	http://eprints.iisc.ac.in/id/eprint/35282

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