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.

Abstract: This is an improvement to a travelling wave heat engine. The latter uses acoustical travelling waves to force a gas in a differentially heated regenerator to undergo a Stirling thermodynamic cycle and thereby converts thermal energy into acoustical energy or vice versa, depending on the direction of the wave propagation. This patent concerns the addition of a resonant cavity around the regenerator to superimpose a standing wave to the travelling wave in order to augment the pressure component of the travelling wave without adding to the velocity component. This increases the level of acoustical power that can be put through the engine for a given level of regenerator viscous loss and so increases the engine's specific power which is limited by regenerator viscous losses.