航空发动机整机振动测量和分析方法

Vibration measurement and analysis of aero-engine

摘要:

目前国内仍有很多航空发动机试车台使用的是模拟振动测量仪,滤波和积分选择均需针对机型专门定制,灵活性不够,同时也不能分析振动频率,满足不了发动机振动分析的要求。选择合适的振动传感器、振动测量仪并采用合适的软件分析方法,迅速准确地测量发动机的振动值并分析振动频率是发动机厂、所对发动机整机台架试验的要求。在发动机整机振动测量选择了压电式加速度传感器并使用带有抗混滤波的差分放大器以消除频率混叠和共模干扰,编写了专门的振动分析软件,在振动分析软件处理中采用Butterworth滤波器和Flat Top窗函数。该方法能够满足发动机生产厂提出的通带平滑度≤±5%,阻带衰减大于-30dB/倍频程的滤波要求以及对振动测量精度≤±5%的要求。通过研究提出的航空发动机整机振动测量方法准确可靠,能够满足发动机厂、所对试车台架整机振动测量的要求。

Abstract:

At present, there are still many aero-engine test cell using analog vibration measuring instruments. Filtering and integral selection need to be tailored for the aero-engine type. The flexibility is not enough, and the vibration frequency can not be analyzed, which can not meet the requirements of engine vibration analysis. Choosing the appropriate vibration sensor, vibration measuring instrument and adopting the appropriate software analysis method, measuring the engine vibration value quickly and accurately and analyzing the vibration frequency are the requirements of engine factory and engine test. In this paper, the piezoelectric accelerometer is selected for the vibration measurement of the engine and the differential amplifier with anti-aliasing filter is used to eliminate frequency aliasing and common mode interference. Special vibration analysis software has been compiled, Butterworth filter and Flat Top window function are used in the vibration analysis software. This method can satisfy the filtering requirements of pass-band smoothness < 5%, stopband attenuation greater than - 30dB / octave and vibration measurement accuracy < 5%. The vibration measurement method proposed in this paper is accurate and reliable, and can meet the requirements of engine factory and test cell vibration measurement.