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Advances in Acoustics and Vibration
Volume 2012 (2012), Article ID 473531, 13 pages
http://dx.doi.org/10.1155/2012/473531
Research Article

Sound Scattering by a Flexible Plate Embedded on Free Surface

1School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK
2Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, MO 63103, USA
3Faculty of Engineering, Tel-Aviv University, 69978 Tel Aviv, Israel

Received 10 April 2012; Revised 9 August 2012; Accepted 10 August 2012

Academic Editor: Rama Bhat

Copyright © 2012 Eldad J. Avital et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Sound wave scattering by a flexible plate embedded on water surface is considered. Linear acoustics and plate elasticity are assumed. The aim is to assess the effect of the plate’s flexibility on sound scattering and the potential in using that flexibility for this purpose. A combined sound-structure solution is used, which is based on a Fourier transform of the sound field and a finite-difference numerical-solution of the plate’s dynamics. The solution is implemented for a circular plate subject to a perpendicular incoming monochromatic sound wave. A very good agreement is achieved with a finite-difference solution of the sound field. It is shown that the flexibility of the plate dampens its scattered sound wave regardless of the type of the plate’s edge support. A hole in the plate is shown to further scatter the sound wave to form maxima in the near sound field. It is suggested that applying an external oscillatory pressure on the plate can reduce significantly and even eliminate its scattered wave, thus making the plate close to acoustically invisible. A uniformly distributed external pressure is found capable of achieving that aim as long as the plate is free edged or is not highly acoustically noncompact.