Influence of acoustic impedance in a locally hot region on a thermoacoustic system

Abstract

In a traveling-wave type thermoacoustic system using a heat phase adjuster (HPA), the sound field control by the local thermal input to the acoustic tube is examined. Focusing the attention on the acoustic boundary conditions produced by a HPA, when the sound pulse is emitted from a loudspeaker, the reflection at the setting position of the HPA is observed. As a result, it is suggested that the reflection phenomenon which takes place corresponding to the operation condition of HPA is a contributing factor to control the sound field in the stack. Regarding the influence of a prime mover (PM) stack and a HPA on the sound field in the tube, it is found that, while PM stack is dominant at low electric power driving of a HPA, the HPA becomes conversely dominant at high-power driving. From this result, a possibility to dynamically control the energy conversion quantity in the stack by using a HPA is shown.