热声系统工作介质共振频率的研究  

Research on Resonant Frequency of Working Medium of Thermoacoustic System

作　　者：汪建新[1] 刘向斌 Wang Jianxin;Liu Xiangbin(School of Mechanical Engineering,Inner Mongolia University of Science and Technology,Baotou,Inner Mongolia 014010,China)

机构地区：[1]内蒙古科技大学机械工程学院,内蒙古包头014010

出　　处：《机电工程技术》2025年第2期83-86,99,共5页Mechanical & Electrical Engineering Technology

基　　金：国家自然科学基金项目(52266005)。

摘　　要：为提高谐振腔中声场强度,实现气体大幅交变流动,以气体动力学理论为基础,建立了驻波型热声制冷机气柱振动的数学模型。将谐振腔与声容连接端的声阻抗作为边界条件,推导出谐振腔中任意位置的声阻抗表达式。当圆柱形谐振腔长度为600 mm、直径为100 mm、工作介质为空气时,通过声阻抗表达式对气柱活塞模态振动频率进行计算,得到了气柱活塞模态振动的1阶和2阶频率。在ANSYS中建立了气柱有限元模型,通过模态分析得到了气柱前20阶模态的固有频率,将1阶和2阶活塞模态频率与声阻抗表达式的计算结果相比,其数值吻合性较好,从而验证了声阻抗表达式求解活塞模态频率的正确性。以气柱的长度和横截面积为变量,分析了不同参数下气柱振动的幅频特性,发现气柱在1阶活塞模态频率附近产生的振幅较其他地方有明显提高,因此在热声制冷系统设计中,可用气柱1阶活塞模态振动代替驻波振动,探索提高声场强度的途径。In order to increase the intensity of sound field in the resonator and realize the large alternating flow of gas,a mathematical model of gas column vibration in a standing wave thermoacoustic refrigerator is established based on the gas dynamics theory.Taking the acoustic impedance of the connecting end of the resonator and the acoustic capacitance as the boundary condition,the expression of acoustic impedance at any position in the resonator is derived.When the length of the cylindrical resonator is 600 mm,the diameter is 100 mm,and the working medium is air,the modal vibration frequency of the gas column piston is calculated by the acoustic impedance expression,and the first and second order frequencies of the gas column piston modal vibration are obtained.Finite element model of gas column is established in ANSYS,and natural frequencies of the first 20 modes of gas column are obtained through modal analysis.Compared with the calculated results of the first and second order piston modal frequencies and the acoustic impedance expressions,the numerical agreement is better,thus verifying the correctness of the acoustic impedance expressions for solving the piston modal frequencies.The amplitude-frequency characteristics of the gas column vibration under different parameters are analyzed with the length and cross-section area of the gas column as variables.It is found that the amplitude of the gas column near the first-order piston mode frequency is significantly higher than that in other places.Therefore,the firstorder piston mode vibration of the gas column can be used to replace the standing wave vibration in the design of thermoacoustic refrigeration system,and the way to improve the sound field intensity is explored.

关 键 词：热声系统 气柱振动 声阻抗 有限元分析 

分 类 号：TB66[一般工业技术—制冷工程]