Chapter 84 - Investigation on acoustic characteristics of regenerator in the thermoacoustic apparatus

Abstract

This chapter explores an acoustic-driven thermoacoustic device, which is used to investigate the acoustic characteristics of regenerator. A series of experiments has been performed. The transfer function method is applied, which uses a broadband random signal as a sound source to measure the transfer function of regenerator over a broadband frequency range. Based on the model given in this chapter, reflection coefficient, transmission loss, characteristic impedance, and propagation constant are calculated from the measured transfer function to enrich network parameters of regenerator. The transfer function method is used to measure the transfer function H of regenerator over a broadband frequency range. Reflection coefficient R, transmission loss TL, characteristic impedance Zc and propagation constant γ are calculated from measured H. Heat exchanger has significant influence on acoustic characteristics, which results in acoustic characteristics larger than the case without heat exchanger. Reflection coefficient, characteristic impedance and propagation constant decrease with the increase of heat power to the hot heat exchanger, whereas transmission loss increases with the increase of heat power.