Controlling of loop-tube type thermoacoustic system using heat phase adjuster examination of the control mechanism using a physical model of the heat phase adjuster

For the practical realization of the loop-tube type thermoacoustic system, a technique of heat phase adjuster (HPA) has previously been presented for controlling the resonance mode and improving the energy conversion efficiency by locally supplying a heat input. In order to theoretically examine the mechanism of such ability of HPA from an acoustic view point, the physical model for HPA is presented. In this model, the sound field of each resonance mode changing with the setting position of HPA as well as the temperature of HPA is theoretically discussed. As a result, it is found that HPA controls the resonance mode by making only the sound wave of a specific resonance mode propagate in the positive direction and furthermore the energy conversion efficiency changes with the phase shift of the incident wave from the reflected wave dependent on the temperature of HPA. (C) 2020 The Japan Society of Applied Physics