High Speed Continuous Blade Health Monitoring for Turbine Engines

There are several ongoing challenges in non-contacting stress measurement systems (NSMS) that have limited the applicability of blade tip sensors for general purpose blade health monitoring. Two of the most pressing needs to address are the undersampling that is inherent in time-of-arrival data processing and the uncertainty that is introduced by inferring, as opposed to calculating, the mode of vibration. Advancements in NSMS capability and utilizing multiple blade tip sensors has reduced the uncertainty with identification of the vibration mode and also reduced the undersampling error, but this works against the real-world limits on the size, weight, and reliability of the measurement system as a whole. This project addresses the limitations in current NSMS systems by developing an innovative continuous monitoring system with the following capabilities: • Provides a continuous time series of blade displacement data over a portion of a revolution (solving the undersampling problem). • Includes data reduction algorithms to directly calculate the blade vibration frequency, modal displacement, and vibratory stress (solving the mode inference problem). • Uses a single sensor per stage to monitor all of the blades on the stage.