Accession Number : ADD017342

Title :   Thermoacoustic sound Generator.

Descriptive Note : Patent, Filed 31 May 91, patented 29 Nov 94,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Gabrielson, Thomas B

Report Date : 29 Nov 1994

Pagination or Media Count : 10

Abstract : A submersible acoustic generator for projection of sound waves into a body of water comprises a tubular resonator, open at its lower end and closed at its upper end, and having a multiple-plate thermoacoustic stack located near the upper end between a pair of heat ex changers which set up a temperature gradient in the stack The upper heat exchanger is heated by a chemical fuel, and the lower heat exchanger is cooled by the surrounding water. The resonator is gas-filled, and the wavelength of the oscillations produced is approximately twice the length of the resonator. A portion of the resonator tube can be surrounded by a coaxial tube which serves as an impedance matching stub. The stack plates can be made anisotropic by means of embedded copper wires. In alternative versions of the apparatus, the resonator can have two stacks, one near the open end and the other near the closed end, and the temperature gradient in the stack can be established cryogenically. (MM)

Descriptors :   *TEMPERATURE GRADIENTS, *SOUND WAVES, *UNDERWATER ACOUSTICS, *PATENTS, *SOUND GENERATORS, HEAT TRANSFER, ACOUSTIC WAVES, HEAT EXCHANGERS, COOLING, CRYOGENICS, SUBMERSIBLES, COAXIAL CABLES

Subject Categories : Acoustics
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE