ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

2pSA2. Sonar baffles.

Ronald P. Radlinski

Naval Undersea Warfare Ctr., Detachment New London, New London, CT 06320

Acoustic decoupling baffles are often used to minimize noise contamination at hydrophone and transducer arrays. To maintain sensitivity near the nominally pressure release surface of the baffle, hydrophones can be placed at an odd multiple of a quarter wavelength from the baffle or near a heavy signal conditioning plate inserted between the hydrophones and the baffle. In either case, coherent interference between the incident wave and the wave reflected from the baffle limits the bandwidth of high sensitivity. Wayne Reader reasoned that by inserting a broadband absorber between the hydrophones and the decoupling baffle, a smoother hydrophone response could be attained of potentially less weight with relatively small loss in sensitivity. The talk describes the use of gradual transition absorbers developed by Wayne for sonar applications and his interactions with the author to combine these materials with broadband decouplers such as arrays of compliant tubes. His careful and thoughtful approach to the theoretical and experimental aspects of acoustic and material research was inspirational and we miss his insight, advice, and encouragement.