Acoustic scattering by baffled membranes
作者:
Gregory A. Kriegsmann,
Andrew Norris,
Edward L. Reiss,
期刊:
The Journal of the Acoustical Society of America
(AIP Available online 1984)
卷期:
Volume 75,
issue 3
页码: 685-694
ISSN:0001-4966
年代: 1984
DOI:10.1121/1.390579
出版商: Acoustical Society of America
关键词: sound waves;scattering;baffles;membranes;resonance;asymptotic solutions
数据来源: AIP
摘要:
A flexible membrane is set in an infinite plane baffle. The plane separates an acoustic field from a vacuum. A time harmonic wave is incident from the fluid on the membrane. When the frequency of the incident wave is not close to anin‐vacuoresonant frequency of the membrane, the reaction of the fluid on the membrane is small. However, near a resonant frequency the fluid–membrane coupling is significant. We use the method of matched asymptotic expansions to obtain an asymptotic expansion of the scattered field. It is uniformly valid in the incident frequency. The expansion parameter ε≪1 is the ratio of the fluid and membrane densities. The outer expansion, valid away from resonance, isO(ε). The inner expansion, valid near resonance, is of order unity. The fluid loading is shown to have the effect of decreasing the resonant frequencies from those of thein‐vacuomembrane. Simple and double resonant frequencies are analyzed. However, the method is applicable to higher order resonant frequencies. Finally, the method is applied to normal incidence of a plane wave on a circular membrane.
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