Thermoacoustic Stirling engines: A review

Thermoacoustic Stirling engines (TASEs) are the acoustic equivalents of Stirling engines. They have attracted much attention from researchers due to their unique features such as low manufacturing cost, high efficiency, maintenance-free characteristics, and self-starting nature. This paper reviews the state of literature to investigate the components of thermoacoustic Stirling engines and determine the effect of each component on the overall performance of these engines. To achieve this goal, the important components such as regenerator, inertance, resonator (stub), compliance, and buffer tubes are investigated. This review work shows that applying changes in dimensions or locations of the engine components influences the performance of such engines, and also reveals the essentiality of a careful design. Besides, it is shown that increasing the number of regenerators (core section) in the engine results in the performance improvement of the engine. In addition to that, the appropriate location of compliance in the looped-tube is about lambda/4 and 3 lambda/4 away from the core section and this factor is lambda/2 for inertance section as well. Also, the effect of changing other mechanical components on the engine performance is predicted. Next, this study reviews the effect of fluid parameters of the thermoacoustic Stirling engines (i.e. temperature, mean pressure, output power, and amplitude of pressure changes) on each other. Finally, all thermoacoustic Stirling engines that have been developed so far, were reviewed. This review work confirms the increasing interest of researchers in working and researching in this field in the past recent years due to the highlighted benefits.