Parameter sensitivities analysis for classical flutter speed of a horizontal axis wind turbine blade

Abstract

The parameter sensitivities affecting the flutter speed of the NREL (National Renewable Energy Laboratory) 5-MW baseline HAWT (horizontal axis wind turbine) blades are analyzed. An aeroelastic model, which comprises an aerodynamic part to calculate the aerodynamic loads and a structural part to determine the structural dynamic responses, is established to describe the classical flutter of the blades. For the aerodynamic part, Theodorsen unsteady aerodynamics model is used. For the structural part, Lagrange’s equation is employed. The flutter speed is determined by introducing “V–g” method to the aeroelastic model, which converts the issue of classical flutter speed determination into an eigenvalue problem. Furthermore, the time domain aeroelastic response of the wind turbine blade section is obtained with employing Runge-Kutta method. The results show that four cases (i.e., reducing the blade torsional stiffness, moving the center of gravity or the elastic axis towards the trailing edge of the section, and placing the turbine in high air density area) will decrease the flutter speed. Therefore, the judicious selection of the four parameters (the torsional stiffness, the chordwise position of the center of gravity, the elastic axis position and air density) can increase the relative inflow speed at the blade section associated with the onset of flutter.

Keywords

wind turbine blade / aeroelastic model / classical flutter / parameter sensitivities analysis

References

[1] PeeringaJ, BroodR, CeyhanO, EngelsW d, WinkelGUp wind 20MW wind turbine pre-design [R], 2011, Petten, Energy Research Center of the Netherlands

[2] HauE. Wind turbines-fundamentals, technologies, application, economics [J]. IEEE Electrical Insulation Magazine, 2003, 19(2): 48

[3] BirG, JonkmanJAeroelastic instabilities of large offshore and onshore wind turbines [C]//EAWE 2007 Torque, 2007, Lyngby, IOP: 1-19

[4] HansenMOL, SørensenJ N, VoutsinasS, SørensenN, MadsenH A. State of the art in wind turbine aerodynamics and aeroelasticity [J]. Progress in Aerospace Sciences, 2006, 42(4): 285-330

[5] LundsagerP, PetersenH, FrandsenSThe dynamic behaviour of the stall-regulated Nibe A wind turbine, 1981, Measurements and a model for stall-induced vibrations [R]. Roskilde, Risø National Laboratory

[6] StiesdalHExtreme wind loads on stall regulated wind turbines [C]//Proceedings of the 16th British Wind Energy Association Conference, 1994, Stirling, BWEA: 101106

[7] WangL, LiuX, RenevierN, StablesM, HallG M. Nonlinear aeroelastic modelling for wind turbine blades based on blade element momentum theory and geometrically exact beam theory [J]. Energy, 2014, 76: 487-501

[8] RafieeR, TahaniM, MoradiM. Simulation of aeroelastic behavior in a composite wind turbine blade [J]. Journal of Wind Engineering and Industrial Aerodynamics, 2016, 151(1): 60-69

[9] HayatK, LeceaA, MorionesC D, HaS K. Flutter performance of bend–twist coupled large-scale wind turbine blades [J]. Journal of Sound and Vibration, 2016, 370(1): 149-162

[10] LobitzD W. Aeroelastic stability predictions for a MW-sized blade [J]. Wind Energy, 2004, 7(3): 211-224

[11] LobitzD W, VeersP S. Aeroelastic behavior of twist-coupled HAWT blades [J]. AIAA Paper, 1998, 98(29): 75-83

[12] BaxevanouC, ChaviaropoulosP, VoutsinasS, VlachosN. Evaluation study of a Navier–Stokes CFD aeroelastic model of wind turbine airfoils in classical flutter [J]. Journal of Wind Engineering and Industrial Aerodynamics, 2008, 96(8): 1425-1443

[13] HoogedoornE, JacobsG B, BeyeneA. Aero-elastic behavior of a flexible blade for wind turbine application: A 2D computational study [J]. Energy, 2010, 35(2): 778-785

[14] DrelaMAn analysis and design system for low Reynolds number airfoil aerodynamics [C]//Low Reynolds Number Airfoil Aerodynamics, 1989, Indiana, Springer Berlin Heidelberg: 112

[15] LiL, LiY, LvH, LiuQ. Flapwise dynamic response of a wind turbine blade in super-harmonic resonance [J]. Journal of Sound and Vibration, 2012, 331(17): 4025-4044

[16] MoW, LiD, WangX, ZhongC. Aeroelastic coupling analysis of the flexible blade of a wind turbine [J]. Energy, 2015, 89(1): 1001-1009

[17] OwensB C, GriffithD, ResorB R, HurtadoJ EImpact of modeling approach on flutter predictions for very large wind turbine blade designs [C]//Proceedings of the American Helicopter Society (AHS) 69th Annual Forum, 2013, Arizona, AHS: 2123

[18] HansenM H. Aeroelastic instability problems for wind turbines [J]. Wind Energy, 2007, 10(6): 551-577

[19] TheodorsenTGeneral theory of aerodynamic instability and the mechanism of flutter [R], 1949, Washington, DC, National Advisory Committee for Aeronautics: 291313

[20] WrightJ R, CooperJ EIntroduction to aircraft aeroelasticity and loads [M], 2008, Chichester, John Wiley & Sons

[21] GwinL, TaylorR. A general method for flutter optimization [J]. AIAA Journal, 1973, 11(12): 1613-1617

[22] JonkmanJ M, ButterfieldS, MusialW, ScottGDefinition of a 5-MW reference wind turbine for offshore system development [R], 2009, Colorado, National Renewable Energy Laboratory Golden

[23] LindenburgCAeroelastic modelling of the LMH64-5 blade [R], 2002, Petten, Energy Research Center of the Netherlands