发动机叶尖间隙微波测量法的相位补偿

Phase Compensation for Microwave Testing of Engine Tip Clearance

本文对发动机叶片叶尖间隙大小的微波测量方式进行相位补偿进行了研究。通过在微波探头端面加装环,采用线缆变温分离环形器泄露信号和探头+环的反射信号,得到较为干净的探头+环的反射信号作为参考信号,利用探头+环反射信号的相位变化补偿叶片信号的相位变化。本方案既能在实际的发动机实时叶尖间隙测量上实现,又能有效补偿线缆温度变化引起的叶片相位变化,有效提高叶尖间隙的测量精度,克服了测试过程中温度变化对测试精度的影响。

In this paper,the temperature compensation of the microwave measurement method of the engine blade tip clearance is studied.By installing a ring on the end face of the microwave probe,the cable variable temperature is used to separate the leakage signal of the circulator and the reflection signal of the probe+ring,and the relatively clean reflection signal of the probe+ring is obtained as the reference signal.The phase change of the probe+ring reflection signal is used to compensate the phase change of the blade signal.This scheme can not only be realized in the real time tip clearance measurement of the engine,but also can effectively compensate the blade phase change caused by the cable temperature change,effectively improve the measurement accuracy of tip clearance,and overcome the impact of temperature change on the test accuracy during the test process.