Propagation of sound out of a fluid wedge into an underlying fluid substrate of greater sound speed

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Authors
Coppens, Alan B.
Humphries, M.
Sanders, James V.
Subjects
Advisors
Date of Issue
1980-07
Date
Publisher
Acoustical Society of America
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Abstract
A Green’s function extension of image theory allows the sound field in an absorbing fluid substrate underlying a fluid wedge of slower sound speed to be evaluated on a desktop computer. (1) Solutions based on an end‐point approximation, valid at great distances from the apex of the wedge and for absorptions representative of sedimentarylike materials, show a beam peaking at a depth close to that predicted by more complicated models. An additional random‐phase assumption provides a functional dependence for this angle identical with that obtained by a more elaborate procedure. (2) Solutions based on a saddle‐point approximation are valid below the apex and for arbitrary absorption. At moderate absorption, these solutions are consistent with those observed in the farfield. For small absorption, the sound field displays a heretofore unnoticed structure that is consistent with the mutual interference of sound beams entering the substrate at various distances from the apex. Some previously unreported measurements of the sound field in the substrate support the predictions of the saddle‐point approximation.
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Article
Description
The article of record as published may be found at https://doi.org/10.1121/1.391429
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Department
Physics
Organization
Naval Postgraduate School (U.S.)
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NPS Report Number
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Format
10 p.
Citation
Coppens, Alan B., M. Humphries, and James V. Sanders. "Propagation of sound out of a fluid wedge into an underlying fluid substrate of greater sound speed." The Journal of the Acoustical Society of America 76.5 (1984): 1456-1465.
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This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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