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NTUA. Advanced Aeroelastic Modeling of Complete Wind Turbine Configuration in View of Assessing Stability Characteristics. V.A.Riziotis and S.G.Voutsinas National Technical University of Athens School of Mechanical Engineering Fluids Section. Overview of the Presentation.
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NTUA Advanced Aeroelastic Modeling of Complete Wind Turbine Configuration in View of Assessing Stability Characteristics V.A.Riziotis and S.G.Voutsinas National Technical University of Athens School of Mechanical Engineering Fluids Section EWEC’06 Athens 27 February-2 March 2006
Excitation Method Non-linear damping identification • wind turbine modes are excited, • by individual blade pitch (rotor modes and tower fore aft mode) • by point force applied at tower top (tower modes) • duration of excitation 15sec • pitch amplitude 2o • tower force amplitude 2.5 ton • damping extracted from transient loads time-series 5 rev 15 s
Δt Δt t0 -ζ Ωn Damping Identification Methods moving block method
900 phase shift Damping Identification Methods Hilbert method A(t): envelope signal
Comparison with Measurements 1st tower lateral bending
Comparison with Measurements 1st tower longitudinal bending
Comparison with Measurements reduction of damping beyond 16m/s is associated with the inability of the damping identification method to predict well the damping of spectrally close modes
Comparison with Measurements r/R = 0.40 r/R = 0.85
Comparison with Measurements 1st regressive rotor lead-lag
Comparison with Measurements 1st progressive rotor lead-lag
Comparison of damping Identification Methods 1st tower lateral bending 1st tower longitudinal bending
12 m/s 16 m/s Comparison of damping Identification Methods
Acknowledgements • European Commission for funding this work under contract NNK5-CT2002-00627 (STABCON project) • STABCON project partners for publishing of the paper