In-Service Signal Processing Code to Monitor for Cumulative Defects in Engine Airfoils

Technology is proposed for in-service detection of airfoil and rotor defects, and of operating conditions that can accelerate them. The technology consists of deterministic signal processing algorithms that fundamentally advance spectrum analyzer technology for extracting torsional vibration signals from operating turbines. Newly patented analytical methods for constant velocity power turbines will be generalized to accommodate the effects of acceleration in high performance aircraft turbines. The resulting technology will continuously extract airfoil and rotor resonances and track their frequency shifts as a means to detect integrity-reducing structural changes in those engine components. The current project will also code the generalized method and test it with data collected during on-going, full-scale compressor tests, with the results being compared with strain gauge data. The resulting technology will provide continuous resonance information for in-flight or ground-based use. In-flight uses include detecting defects and such conditions as airfoil flutter or contamination. Ground-based uses include design, development and testing, including maintenance inspections.