Accession Number:

ADA242913

Title:

On the Use of Sympathetic Resonators to Improve Low-Frequency Underwater Transducer Performance

Descriptive Note:

Technical rept. Jan-Sep 90,

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF PHYSICS

Personal Author(s):

Report Date:

1991-10-01

Pagination or Media Count:

68.0

Abstract:

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 karesonator, katransducer 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.

Subject Categories:

  • Submarine Engineering
  • Nuclear Radiation Shielding, Protection and Safety

Distribution Statement:

APPROVED FOR PUBLIC RELEASE