Condition Monitoring Diagnosis Method of Aircraft Engine Rotating Details

摘要

Presented work is dedicated to development of the new passive-active low-frequency automatic vibroacoustical early fault diagnosis method of aircraft gas-turbine engine units (compressor stages, turbine stages), which contain the rotating details (blades, disks, shafts, etc.). The proposed method is condition monitoring and can be used while engine is operating. The method is based on testing object non-stationary narrow-band vibratory excitation with the variable central frequency, and signal processing of the engine vibro and acoustical noise in the low-frequency range (0-50 kHz). As the testing object the blade is considered at the presence and the absence of the fatigue crack. In this paper the theoretical correlation and spectral researches are given for the testing object non-stationary oscillations without and with the above mentioned fault. For nondestructive evaluation of the relative fault size the feature set, components of which are higher and basic harmonics spectral amplitudes ratios is used. The evaluation is produced by using the generalized likelihood ratio (GLR) method. The estimations statistics are computed.