Abstract: A thermoacoustic engine-generator that converts waste heat into electrical power. Thermal energy is converted to useful work via temperature-pressure amplification of periodic acoustic traveling waves in a compressible working fluid which cause the armature of a linear alternator to reciprocate and produce alternating current electrical energy. An external oscillator initiates reciprocating motion in the armature of a linear alternator. The armature is a combination fluid pump and fluid motor as well as the induction armature of a linear alternator. The pump end of the armature generates an acoustic traveling wave with each cycle of the armature. The traveling wave enters a waveguide-heat exchanger and is amplified in temperature, pressure and propagation velocity by thermal conduction of energy through the wall of the waveguide.

Abstract: A Thermo-Acoustic Resonator (TAR) is a miniature thermoacoustic heat pump and thermal-electric generator that is typically imbedded in a thermoplastic or metal package. The TAR converts a thermal gradient into electrical energy. It can range in size from that of a microchip, upward. The operable principle is that sensible and latent heat in a material can be pumped most efficiently when pumped at intervals that are resonant with the natural period of the material at a given temperature, thereby increasing the energy density of the thermoacoustic engine. The normal period of the device is tailored to produce thermodynamic oscillation in the heat exchangers and working fluid, and thereby to cause a miniature armature to reciprocate within a magnetic field and generate alternating current. Power output depends on the amplitude and frequency of the thermal gradient, and the tailored energy flow rate through the device.