Development of a self-circulating heat exchanger for thermoacoustic devices

Abstract

When sound waves propagate in a tube, a secondary flow called acoustic streaming is sometimes generated. This study focuses on the circulating acoustic mass flow that flows in one direction in a looped tube and is a type of acoustic streaming. A heat transport device based on the circulating acoustic mass flow was developed by Backhaus and Swift, and they called it a self-circulating heat exchanger. It consists of a loop tube and an acoustic flow generator. This acoustic flow generator plays an important role; however, its structure and installation method—to efficiently generate the circulating acoustic mass flow—have not yet been clarified. Therefore, this study aims to establish a design method for a self-circulating heat exchanger. In previous studies, the generation of circulating acoustic mass flow was confirmed and a method for measuring the mass flow rate was established. In this study, we experimentally investigated how the circulating acoustic mass flow changes by changing the installation position of the acoustic flow generator and the driving power of the speaker. It was found that the magnitude of the circulating acoustic mass flow changed by changing the installation position of the acoustic flow generator.