动密封转子动力特性谐波激励实验测试方法  

The Harmonic Excitation Mechanical Impedance Method for the Measurements of Rotordynamic Characteristics of Rotating Seals

作　　者：方志 李志刚[1] 王天昊 薛文松 李军[1] FANG Zhi;LI Zhigang;WANG Tianhao;XUE Wensong;LI Jun(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2022年第6期85-96,共12页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51776152)。

摘　　要：针对动密封性能实验研究需求,设计搭建了基于谐波激励机械阻抗法的动密封转子动力特性实验台。实验台包括供气系统、驱动系统、润滑系统、激振系统以及测量系统5个部分。实验测试原理:利用电磁激振器对密封静子件分别施加x和y两个正交方向的单频/多频谐波激励,同步测量密封静子件涡动位移、涡动加速度以及所受的激振力等动态信号,通过无压缩气体的基准实验解耦实验台机械阻抗和动密封气流阻抗,求解力-位移线性方程,获得频率相关的动密封转子动力特性系数。该实验台能够开展不同运行工况(压比、转速、预旋比和偏心率)、不同密封结构(迷宫、蜂窝/孔型、袋型密封等非接触式动密封)和不同密封间隙下的频率相关转子动力特性系数实验测量。利用搭建的实验台对典型迷宫密封开展了泄漏与转子动力特性测量,验证了实验台的可靠性与准确性。The development of the domestic advanced rotating seals technology is limited due to the lack of detailed experimental researches and reliable high-precision test rig.Therefore,in this paper,a high-precision rotordynamic characteristic test rig for rotating seals were built,and it is based on the wave excitation mechanical impedance method.The test rig includes five systems:air supply system,drive system,lubrication system,excitation system,and measurement system.During the test,two electromagnetic shakers were utilized to apply the single frequency or multi frequency harmonic excitation on the stator in both orthogonal(x-and y-)directions,and the force excitation signal,the response displacement and accelerated speed were synchronously measured,which can be used to finally solve force-displacement linear equation through the mechanical impedance of the uncompressed-gas benchmark decoupling test rig and the flow impedance of rotating seals and obtain the frequency-dependent rotordynamic characteristic coefficients of rotating seals.Utilizing the test rip,the frequency-dependent rotordynamic characteristic coefficients of rotating seals can be obtained under different operating conditions(including the inlet and outlet pressure ratio,rotational speed,inlet swirl speed,and eccentricity ratio),different sealing structures(non-contact rotating seals such as labyrinth seals,hole-pattern/honeycomb seals,and pocket seals)and different sealing clearances.In this paper,the detailed structure,measuring instrument and experimental principle of the test rig were described,and the leakage and rotordynamic characteristic were measured for a typical labyrinth seal which confirmed the feasibility and accuracy of the test rig.

关 键 词：动密封 转子动力特性 实验台 谐波激励 机械阻抗法 

分 类 号：TK476[动力工程及工程热物理—动力机械及工程]