METHOD AND APPARATUS FOR DETECTING AND IDENTIFYING EXCESSIVELY VIBRATING BLADES OF A TURBOMACHINE

摘要

A method and apparatus for detecting and identifying one or more excessively vibrating blades (14) of the rotating portion of a turbomachine (10) utilizing analysis of the characteristic Doppler waveform that results as the rotating, vibrating blade (14) passes a fixed sensor (20). The acoustic energy in the vicinity of the rotating portion of the turbomachine (10) is sensed to generate a composite electrical signal representative of the broadband acoustic spectrum. Then, through both time domain and frequency domain signal manipulations, the undesirable noise components of the composite signal are removed. The resulting signal is then displayed to reveal the characteristic Doppler waveform of the blade (14) vibrations, which may be analyzed to indicate the location of the excessively vibrating blade (14) as well as its relative vibration amplitude. Changes in the latter with time indicate the initiation or propagation of a blade crack.