On the use of sympathetic resonators to improve low-frequency underwater transducer performance
By: S. R. Baker and J. M. Ellsworth
Contributors: Ellsworth, John Merle; Naval Postgraduate School (U.S.). Dept. of Physics
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1991
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 68
Subjects: Underwater transducers
Other titles: NPS-PH-92-002.
Description: The achievable gain in the radiation resistance and directivity of a low-frequency      underwater transducer due to the presence of an array of sympathetic resonators has      been analyzed. The resonators were all taken to be air bubbles, and both the resonators      and transducer were taken to be compact (ka << 1). The resonators were taken to be      equally spaced around a circle of radius R, with the transducer located on the axis. The      gain was calculated for various numbers of resonators as a function of ka(resonator),      ka(transducer) and kR, for the transducer in the plane of the resonators and out of the      plane a distance of one-quarter wavelength. For the transducer in the plane, a gain in      radiation resistance of approximately two is possible with six or more resonators. For the      transducer out of the plane, it is shown that a front-to-back discrimination of      approximately 8 dB can be achieved, at the expense of a decrease of approximately ten      percent in the achievable gain in the radiation resistance, compared to the transducer in      the plane of the resonators.
Notes: Cover title.

"NPS-PH-92-002."

"October 1991."

"Technical report."

AD A242 913.

Includes bibliographical references (p. 62).

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