Abstract: A submersible acoustic generator for projection of sound waves into a body f 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 exchangers 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.

Abstract: This invention is an improved traveling wave ring resonator utilizing only one source of waves. The standard traveling wave ring resonator uses two wave sources phased 90 degrees apart and physically separated by a quarter wavelength to separately excite two equal-frequency standing wave modes which make up a traveling wave. The present invention uses perturbations of the ring resonator to shift the frequency of the standing wave modes, by specified amounts, and to correctly fix their position, to allow a single wave source to properly excite the standing wave modes which comprise a traveling wave. This invention has application to traveling wave ring resonators in acoustics, mechanical devices, and electromagnetic devices, as well as to simply-connected resonators to be excited in rotating wave modes. Specific applications include improved thermoacoustic traveling wave heat engines and pumps, simplified surface wave motors, and energy efficient wave pools for recreational purposes.