航空发动机盘腔积液的故障识别

For the difficulties in monitoring and diagnosing the aero-engine liquid fault, this paper divided the liquid fault into early liquid fault and serious liquid fault and analyzed the vibrations features respectively. Firstly, the influence law of unbalanced quantity and early liquid on rotor vibration was studied. Based on the area distribution characteristics of the amplitude-frequency characteristic curve, one identification criterion for early liquid was proposed. Then, the instability vibration characteristics of serious liquid rotor was analyzed. It was found that the instability due to serious liquid occurred, there would be a sudden increase of vibration amplitude and sub-harmonic even beat vibration. Based on the characteristics, three identification criterions for serious liquid were proposed. Finally, a complete monitoring method and diagnostic process of liquid fault was proposed, which could provide early warning before instability and avoid fault from getting worse. 30 sets of experimental data were selected for verification. The results show that the accuracy of the method proposed is 96%, which has engineering application value.