Single-Probe Blade Tip Timing: A Novel Method for Anomaly Identification Based on Frequency Shift

Abstract

Blades are weak and essential parts of an aeroengine. Monitoring the running state of blades is essential for ensuring the safety of aeroengine operation. Blade tip timing (BTT) is considered a promising technique for operational blade vibration monitoring for turbomachinery; however, it is difficult to analyze the BTT signal because of the inherent undersampled limitation. To overcome this limitation, the minimal sensor layout scheme is restricted to be “three.” Usually, more than five probes are required for good signal revolution. This requirement is an installation restriction that limits the application of BTT; however, for users, the conflict between probe layout optimization and real installation restriction is also a serious problem. Motivated by these issues, a single-probe BTT (SP-BTT) method is proposed; the SP-BTT method could extract the shift between natural frequencies, which could be used as a damage index for blade condition monitoring. To validate the effectiveness of the proposed method, numerical simulations and experimental tests are performed.