基于微波相位差测距的叶尖间隙动态测量方法  

A dynamic measurement method of blade tip clearance based on microwave phase difference ranging

作　　者：牛广越 段发阶[1] 周琦 刘志博 NIU Guangyue;DUAN Fajie;ZHOU Qi;LIU Zhibo(State Key Laboratory of Precision Measuring Technology and Instruments,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《航空学报》2022年第9期194-212,共19页Acta Aeronautica et Astronautica Sinica

基　　金：国家科技重大专项(2017-V-0009);国家自然科学基金(51775377,61971307,61905175);国家重点研发计划项目(2020YFB2010800);中国航发四川燃气涡轮研究院外委课题(GJCZ-2020-0040,GJCZ-2020-0041);霍英东教育基金会资助(171055);中国博士后科学基金(2020M680878);广东省重点研发计划项目(2020B0404030001);天津市科技计划项目(20YDTPJC01660)。

摘　　要：叶尖间隙参数的非接触、高精度、在线测量是保证航空发动机工作效率和运行安全的关键,传统的微波式叶尖间隙静态测量方法易受直流噪声干扰,存在测距模糊问题,信号采样点数时刻变化,直接影响了测量精度。提出了一种基于微波相位差测距原理的叶尖间隙参数动态测量方法。建立了微波式叶尖间隙测量信号模型,仿真分析了不同厚度以及凹腔叶片的信号强度和相位特征,提出了一种相位区域自适应截取、尺度调整、相关匹配、多项式拟合相融合的技术手段,解决了微波相位信号的测距模糊问题,实现了相位信号峰值位置的预估,减小了信号处理过程中的随机误差,实现了叶尖间隙参数的高精度动态测量。研制了基于微波相位差测距的叶尖间隙测量系统原理样机,在实验室环境下搭建了叶尖间隙信号动态测量的实验平台,开展了测量和标定实验。实验结果验证了所提方法的有效性和准确性,测量系统适用于不同厚度以及H形凹腔叶片的叶尖间隙参数测量,在动叶片转速3000r/min的模拟工作环境下,0.5~3mm量程内,不同厚度及H形凹腔叶片的叶尖间隙动态测量精度均优于40μm;且针对2mm厚度的叶片,当模拟的叶片转速高达24000r/min时,0.5~3mm量程内的测量精度仍然优于60μm。Non-contact high-precision online measurement of blade tip clearance is the key to efficiency and safety of aeroengines.However,the traditional static measurement method based on microwave faces the problem of precision decline under the influence of direct current noise,distance measurement ambiguity,and variation of signal sampling time points.Therefore,a dynamic measurement method of blade tip clearance is proposed based on microwave phase difference ranging.A measurement signal model is established.The strength and phase signals of the blades with different thickness and cavity are simulated and analyzed.A new technical method combining techniques of phase region adaptive interception,scale adjustment,correlation matching,and polynomial fitting is proposed to realize high-precision dynamic measurement of blade tip clearance.The method can solve the ambiguity problem of microwave phase signal ranging,realize the estimation of the phase signal’s peak position,and reduce random errors in the signal processing process.A prototype of blade tip clearance measurement is developed based on microwave phase difference ranging,and an experimental platform for dynamic measurement of the blade tip clearance signal is built in the laboratory to carry out measurement and calibration experiments.Experimental results verify the effectiveness and accuracy of the proposed method,which is applicable for measurement of blades of different thicknesses and H-form cavity.For the blade with different thickness and shape,the dynamic measurement accuracy of blade tip clearance is better than 40μm over the range of 0.5mm to 3mm when the rotation speed of the blade is 3000r/min.For the blade with 2mm thickness,the measurement accuracy is still better than 60μm over the range of 0.5mm to 3mm when the speed is up to 24000r/min.

关 键 词：叶尖间隙 动态测量 测距 微波毫米波 相位差 动叶片 相关系数 航空发动机 

分 类 号：V241.9[航空宇航科学与技术—飞行器设计] TH711[机械工程—测试计量技术及仪器]