How to build a loaded thermoacoustic engine

This paper presents an experimental method to predict the operating point of a looped tube thermoacoustic engine combined with an acoustic load. The thermoacoustic engine is divided into two subsystems, one containing the loop and the other containing the load. Their respective acoustic impedances are individually measured using an acoustic driver. Results show that the operating temperature difference and frequency of the loaded engine can be obtained from the measured impedances, before actually combining the subsystems. Furthermore, through measurements of the acoustic power distribution, the frequency best suited to extract the acoustic power from the engine subsystem is identified. Analyzing the subsystems offers a useful method to build a thermoacoustic engine with the desired performance.