Thermoacoustic engine introduction
The thermoacoustic engine is a sound wave generator that utilizes the thermoacoustic effect to realize the conversion of thermal energy to acoustic energy to realize the output of sound power. There are no moving parts in the system other than the oscillating gas. According to the characteristics of the sound field, the thermoacoustic engine is mainly divided into three types: standing wave type, traveling wave type and standing wave traveling wave mixing type. Since the phase difference between the velocity wave and the pressure wave in the standing wave sound field is 90°, there is theoretically no work output in the standing wave field; on the other hand, the heat exchange between the gas and the solid in the standing wave thermoacoustic engine plate stack is poor, the gas The irreversible thermodynamic cycle between isothermal and adiabatic is performed, so the standing wave thermoacoustic engine is inefficient. The traveling wave type thermoacoustic engine utilizes a traveling wave sound field in which the speed fluctuation and the pressure fluctuation phase are the same, and the hydraulic radius of the gas passage in the engine regenerator is much smaller than the gas thermal penetration depth, so theoretically the gas is in the regenerator The isothermal heat transfer is carried out, so the traveling wave thermoacoustic engine can theoretically achieve higher thermodynamic efficiency than the standing wave thermoacoustic engine.