Ground Test Cell Instrumentation and Fleet Health Monitoring/Repair of Integrally Bladed Rotor (IBR) with A/B Mistuned Blades and Asymmetric Vane Excitation

Non-Contact Technologies, LLC, (NCT) seeks to mature and commercialize the integration of Non-contact Stress Measurement System (NSMS) instrumentation techniques for turbine engine blade vibration marketed by NCT with modelling and analysis tools developed by Blade Diagnostics Corporation (BDC) to provide comprehensive analysis of turbine blade vibration during operation in instances where engine design contains mistuned blades with symmetric or asymmetric excitation sources as seen in modern turbine engine design.   The DAF and the Navy currently utilize Integrally Bladed Rotor (IBR) components in turbine engines across the aircraft fleet. Recent turbine engine designs use IBRs with non-homogeneous material and intentionally mistuned blades – i.e., blades with different frequency characteristics – to break cyclic system response. Also, asymmetric guide vanes within the compressor are used with intentionally mistuned blades to reduce issues such as flutter or other blade vibration issues which may cause High Cycle Fatigue (HCF). These design features are expected in future engines such as those developed under the Adaptive Versatile Engine Technology (ADVENT) and the Advanced Turbine Technologies for Affordable Mission-Capability (ATTAM) initiatives. With the introduction of intentionally mistuned blades, combined with engine designs containing asymmetric vanes, current analysis and evaluation techniques may fail to provide information needed to qualify engines for production and flight. The single excitation/single response system identification that characterized vibration modes for traditional turbine engine design is no longer valid. More advanced tools and techniques are required due to the increased number of frequencies and nodal diameter resonances present in the operating range of the IBR presenting numerous multi-mode/beat phenomena. This SBIR project will focus on investigating the complex issue of system identification and measurements of vibration from A/B blade intentionally mistuned IBRs in the presence of symmetric or asymmetric guide vanes. This effort includes developing refined measurement and modelling techniques to accurately predict and characterize these phenomena with results that will provide consistent measurement amplitudes and reduce errors induced by the limitations of current NSMS/strain gage techniques. During the Phase II effort, the team of NCT and BDC will build upon the feasibility study performed by NCT where A/B mistuned NSMS data was simulated to show the current shortfalls in NSMS data processing. Representative A/B mistuned IBRs will be tested during Phase II, and the data will be used to expand the existing measurement and analysis tools developed by NCT and BDC as well as fleet health monitoring advancements. Upon successful demonstration and validation of the techniques, NCT will work with the DAF to determine the specific measurement needs for operation in an engine test cell and the depot.