High-Power Terfenol D Flextensional Transducer. Revision A.
NAVAL UNDERSEA WARFARE CENTER NEWPORT DIV RI
Pagination or Media Count:
A flextensional underwater acoustic projector, powered by Terfenol-D and operated at a depth of 400 ft 122 m, has been driven to a source level of 212 dBmicroPa-m at the Naval Undersea Warfare Centers NUWO Seneca Lake Test Facility. The flextensional shell was a modified Class IV shape having concave, rather than convex, radiating surfaces. The geometry of the shell was similar to one described by Merchant U.S. Patent No. 3,258,738, June 28,1966. The shell cross section was circumscribed by a rectangular area 9.8 x 5.0 inches 250 mm x 126 mm, and the height between the end flanges was 5.8 inches 148 mm. At the resonance frequency of 930 Hz, the projector was omnidirectional, and so the radiated acoustic power was 14 kW. The ac efficiency was 52 percent, and the overall ac dc efficiency was 45 percent. The mass of the transducer was 34 lb-m 15.4 kg. With a mechanical quality factor, Q sub m, of 4.7, the projector figure of merit exceeded 200 Wkg-kHz-Q. The effective coupling factor, measured with the transducer in air, was 0.29.
- Acoustic Detection and Detectors