Experimental study on thermally actuated pressure wave generator for space cryocooler Original Research Article

In this paper, thermally actuated pressure wave generators are studied. Solid displacers instead of long and heavy resonance tubes are used as a resonator for compactness, less vibration and small loss. First, various types of thermoacoustic engine are categorized and discussed in view of energy flow patterns at a regenerator. Next, the work amplifier with solid displacers is demonstrated with the experimental apparatus. The maximum work amplification ratio of 1.6 is obtained. Further, the pressure wave generator with self-actuated oscillation is examined. Results indicate that a progressive-wave type of thermoacoustic engine can produce the largest output of 22 W among tested cases.