A novel multi-stage looped thermoacoustic heat engine using assembly of elastic membrane and a solid mass

A compact looped traveling-wave thermoacoustic heat engine (LTTHE) using an assembly of an elastic membrane (EM) and a solid-mass plate (SP) acting as a resonance unit is proposed in this paper. In the novel configuration, the novel resonance assembly substitutes for the traditional resonance tube to reduce the axial size of the system effectively, leading to a compact-size system. In addition, multiple identical engine units are included in a closed loop to realize efficient thermoacoustic conversion and efficient acoustical transmission. In this paper, a typical three-stage thermoacoustic heat engine operating around 300 Hz is chosen to be studied and optimized numerically based on a thermoacoustic model. Firstly, the influence of key physical parameters on no-load thermodynamic performance is investigated. Then, the system output characteristics are further discussed for a better understanding of the thermoacoustic operation. According to the calculated results, it is shown that this novel thermoacoustic heat engine has the potential of realizing a compact-size and efficient system operating around 300 Hz frequency. (C) 2017 The Authors. Published by Elsevier Ltd.