Influence of resonator shape on nonlinear acoustic field in a thermoacoustic engine

作     者：LIU Danxiao ZHOU Chengguang LIU Ke 

作者机构：Key Laboratory of Noise and Vibration Research Institute of Acoustics Chinese Academy of Sciences Beijing 100190 

出 版 物：《Chinese Journal of Acoustics》 (声学学报（英文版）)

年 卷 期：2012年第31卷第3期

页      面：325-337页

学科分类：080903[工学-微电子学与固体电子学] 080703[工学-动力机械及工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 0807[工学-动力工程及工程热物理] 

基　　金：supported by the National Natural Science Foundation of China(10574135) the Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences(KJCX2-YW-W02) 

主　　题：热声发动机 动态非线性 谐振腔 形状 声场 非线性波动方程 粘性流体力学 振荡频率 

摘      要：The influence of the resonator shape on nonlinear acoustic field in a thermoacous- tic engine is studied. The resonator of themoacoustic engine is boundary driving by a piston at one end, and the other end of it is rigid closed. A one-dimensional wave equation that accounts for gas dynamic nonlinearities and viscous dissipation in the resonator is established based on the governing equations of viscous hydromechanics. The nonlinear wave equation is solved using approximate Galerkin method. The nonlinear acoustic field in four different types of shaped resonators including hyperbolical, exponential, conical and sinusoidal are obtained and compared with that of a cylindrical resonator. It is found that the amplitude and wave- form of the pressure are strongly affected by the resonator shape, the driving amplitude and the oscillation frequency of the piston. Waveform distortion, resonance frequency shift and hysteresis are observed, when the piston oscillation amplitude is large enough. The advantages of shaped resonator for thermoacoustic engine lie in inhibition of higher order harmonics and improvement of pressure ratio, etc.