Study on the Foreign Objects Impact Fault Diagnosis of Aero-Engine Fan Rotor Based on Noise Signal

The detection and identification of foreign object impact events in the working process of aero-engine is very important for the flight safety of aircraft. It is an important research direction to identify the foreign object impact events timely and accurately, send alarm signals, and provide effective disposal suggestions for pilots. Foreign object impact simulation test was carried out on the engine fan rotor foreign object impact simulation test equipment. The noise signal and process image of the foreign object impact were obtained by acoustic measurement of the fan rotor and high-speed photography method. Meanwhile, the time-frequency analysis method of fan rotor noise based on continuous wavelet transform was proposed. Through the noise measurement and analysis test of the impact process of foreign objects on the fan rotor, the fault diagnosis research of foreign object impact was carried out. The time domain and time frequency analysis of the noise signals of foreign objects in different conditions of the fan rotor and different test conditions of different measuring points were carried out. The results show that the acoustic measurement of the fan rotor and the time domain and time frequency analysis method can accurately identify the impact events of foreign objects in the fan rotor, and the frequency and time of foreign objects in the working process can be obtained. This non-contact measurement method is more accurate in identifying impact events of foreign objects than methods based on engine casing vibration monitoring.