Construction and experimental investigation on a solar-powered thermoacoustic engine

A solar-powered thermoacoustic engine, consisting of a dual-axis tracking Fresnel lens collector and a standing-wave thermoacoustic engine, was designed, constructed and tested. Experiments were carried out to examine the influence of working gas, stack thickness and resonator length on the onset temperature, damping temperature and pressure amplitude. Experimental results show that, when the molar ratio of helium is 0.25~0.50, gas mixtures has lower onset and damping temperatures and higher pressure amplitude. When the stack thickness decreases from 0.45 mm to 0.15 mm, the onset and damping temperatures decrease while the pressure amplitude increases. As the resonator becomes longer, the onset and damping temperatures decrease while the pressure amplitude increases. When the resonator is 2.1 m, the engine obtains minimum onset temperature of 297°C, minimum damping temperature of 176°C and maximum pressure amplitude of 69.1 kPa.