www.elsevier.com/locate/ultras
Ultrasonics 44 (2006) e1507–e1509
Experimental study of the influence of different resonators
on thermoacoustic conversion performance
of a thermoacoustic-Stirling heat engine
E.C. Luo a,*, H. Ling a,b, W. Dai a, G.Y. Yu a,b
a Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100080, China
b Graduate School of Chinese Academy of Sciences, Beijing 100049, China
Available online 7 September 2006
Abstract
In this paper, an experimental study of the effect of the resonator shape on the performance of a traveling-wave thermoacoustic engine
is presented. Two different resonators were tested in the thermoacoustic-Stirling heat. One resonator is an iso-diameter one, and the other
is a tapered one. To have a reasonable comparison reference, we keep the same traveling-wave loop, the same resonant frequency and the
same operating pressure. The experiment showed that the resonator shape has significant influence on the global performance of the
thermoacoustic-Stirling heat engine. The tapered resonator gives much better performance than the iso-diameter resonator. The tapered
resonator system achieved a maximum pressure ratio of about 1.3, a maximum net acoustical power output of about 450 W and a highest
thermoacoustic efficiency of about 25%.
2006 Elsevier B.V. All rights reserved.
Keywords: Thermoacoustic-Stirling heat engine; Resonator shape; Tapered resonator
1. Introduction
Heat energy with temperature difference may lead to
self-excited acoustical oscillation under appropriate condi-
tions, which is well known as thermoacoustic oscillation.
One of the most important applications based on the self-
excited thermoacoustic oscillation is a thermoacoustic
prime mover. A traveling-wave thermoacoustic engine
has been paid more and more attention in recent years
due to its potential of realizing higher efficiency than a
standing-wave thermoacoustic heat engine [1,2]. The first
thermoacoustic-Stirling heat engine developed by Back-
haus and Swi