A study of the optimized load of a traveling wave thermoacoustic heat engine

honors thesisCollege of SciencePhysics and AstronomyOrest G. SymkoThermal interaction between differentially heated solid material and ambient gas in a resonator can lead to self-sustained oscillations or the transportation of heat in accordance with the thermoacoustic effect, first explained by Lord Rayleigh. In this research the phenomenon is employed in a looped resonator, utilizing the produced acoustic waves to force gas particles to ndergo a compression, heating, expansion and cooling cycle - i.e. the traveling wave Stirling-approximate cycle - providing an efficient mechanism for generating sound from heat. Some of the energy is subsequently converted to electrical energy through a unimorph piezoelectric device, which then drives a loaded circuit. Our thermoacoustic engine consists of a mechanical component, transforming input heat into acoustical power and an electrical component connected through the piezoelectric device, here acting as a transducer to convert acoustical power into electrical power. These engines may eventually be used to reclaim a significant amount of heat normally expelled as waste from power plants, automobiles, or electronics. The presented work considers the relationship between the power transferred into a load and the resistance (impedance) of the load