Investigation on Gedeon streaming in a traveling wave thermoacoustic engine

Introducing feedback path, traveling wave thermoacoustic engines realize relatively higher efficiency in thermoacoustic conversion. However, the toroidal topology allows acoustically induced streaming, which can seriously degrade performance of traveling wave thermoacoustic engines. With measurements of pressure and temperature distributions as effective approaches, four methods were applied to study the streaming in the thermoacoustic engine. The effects of Gedeon streaming on the temperature profile, the pressure ratio, and the thermoacoustic conversion efficiency of the engine were experimentally investigated. Experiments show that the performance of the engine can be remarkably improved with efficient streaming suppression. When Gedeon streaming is suppressed completely, maximal pressure ratio of 1.302 with nitrogen at 1.57 MPa as working gas and the maximal pressure difference of 0.63 MPa with working pressure at 2.54 MPa were obtained. This research is of importance for further understanding the mechanism of traveling wave thermoacoustic engine.