1 / 14

AEROELASTIC TOOLS FOR 2D AEROFOILS WITH VARIABLE GEOMETRY FOR WIND TURBINE APPLICATIONS

AEROELASTIC TOOLS FOR 2D AEROFOILS WITH VARIABLE GEOMETRY FOR WIND TURBINE APPLICATIONS A. González 1* , X. Munduate 1 , R. Palacios 2 , J.M.R. Graham 2 Wind Energy Department, CENER, Ciudad de la Innovación, 7, Sarriguren, Spain, 31621

uriel-wolfe
Télécharger la présentation

AEROELASTIC TOOLS FOR 2D AEROFOILS WITH VARIABLE GEOMETRY FOR WIND TURBINE APPLICATIONS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. AEROELASTIC TOOLS FOR 2D AEROFOILS WITH VARIABLE GEOMETRY FOR WIND TURBINE APPLICATIONS • A. González1*, X. Munduate1, R. Palacios2, J.M.R. Graham2 • Wind Energy Department, CENER, Ciudad de la Innovación, 7, Sarriguren, Spain, 31621 • Department of Aeronautics, Imperial College, London, SW72AZ, UK • *e-mail: agonzalez@cener.com

  2. Introduction Aeroelastic tools Results Conclusion and future work

  3. Introduction Rotor diameter increase • New technical challenges: • Increased loads • Aeroelastic performance Passive load alleviation Rotational speed control Blade pitch control INSUFFICIENT Ref. UpWind Project Solution: Smart rotor control Blade sections of changing geometry (flaps, variable camber…) • Effective load control: • Aerodynamic efficiency • Blade cost problem Lack of aeroelastic tools!

  4. Introduction CENER ICL Development of unsteady aeroelastic models of aerofoils, including variable geometry + • Levels of modelling of aerofoils with variable geometry: • Classical thin aerofoil theory: • Engineering tools of with very good computational efficiency for preliminary purposes • In-house code AdaptFoil1D (validated) • Panel methods: • Good balance between computational efficiency and accuracy • In-house code AdaptFoil2D (currently in development) • CFD: • Detailed representation of aerofoil and flow, but much higher computational cost

  5. Aeroelastic tools • AdaptFoil1D: • Thin aerofoil theory – Linear kinematics • Based on the work of Peters * • Attached flow • Prescribed deformation: • Large 3-dof rigid-body motion allowed (small effective angle of attack) • Modifications of the meanline geometry under the small displacements assumption • Body dynamics: • 3-dof system of springs and dampers at a single point for rigid body motion • Additional deformation of LE or TE flap, using a static Euler-Bernoulli approach * Peters, D.A., Johnson, M.J., Finite-State airloads for deformable aerofoils on fixed and rotating wings, AD-Vol. 44, Aeroelasticity and Fluid Structure Interaction Problems. * Peters, D.A., Hsieh, A., and Torrero, A., A state-space airloads theory for flexible aerofoils, In Proceedings of the American Helicopter Society, 62nd Annual Forum, Phoenix, AZ, USA, 2006.

  6. Aeroelastic tools • AdaptFoil2D: • Panel methods * - Surface panel code for a thick aerofoil section • Piecewise constant doublets and sources in each panel • The Neumann and Dirichlet conditions are combined • Kutta condition: tangential velocity difference between the upper and lower panels at the TE = shed vorticity • The wake is a doublet panel attached to the TE, transformed into discrete vortices downstream • Free wake and time-stepping method to calculate the wake roll-up • Wake vortices implemented with a lamb vortex core to avoid numerical problems • Attached flow • Prescribed deformation & body dynamics: Idem AdaptFoil1D * Katz, J., Plotkin, A., Low-speed aerodynamics, Cambridge Aerospace Series, 2001.

  7. Results 1. Steady aerodynamics • NACA 0015, α=6º Excellent agreement between AdaptFoil2D and XFoil * * Drela, M., XFOIL: An analysis and design system for low Reynolds number airfoils, Conference on Low Reynolds Number Airfoil Aerodynamics, University of Notre Dame, 1989.

  8. Results 2. Unsteady aerodynamics • Flat plate (NACA 0003) performing a sudden acceleration, α=5º. Comparison between AdaptFoil2D, AdaptFoil1D and a lumped and discrete vortex methods * Excellent comparison. Convergence to the steady values. Inaccuracies for lumped vortex method. * Katz, J., Plotkin, A., Low-speed aerodynamics, Cambridge Aerospace Series, 2001.

  9. Results 2. Unsteady aerodynamics • Flat plate (NACA 0003) performing a sudden acceleration, α=5º

  10. Results 2. Unsteady aerodynamics • NACA 0012, combined pitching and oscillating TE flap • (specific case: ωα=0.021, ωβ=0.042, δ=59º) …compared with experimental data * Good overall agreement for a combined pithing and oscillating TE flap * Krzysiak, A., Narkiewicz, J., Aerodynamic loads on aerofoil with trailing-edge flap pitching with different frequencies, Journal of aircraft, 43(2):407-418, 2006.

  11. Results 2. Unsteady aerodynamics • NACA 0012, combined pitching and oscillating TE flap • (specific case: ωα=0.021, ωβ=0.042, δ=59º)

  12. Results 3. Aeroelastic modelling • Plunge-pitch flat plate (NACA 0003): aerofoil radius of gyration (rα)2=0.25, aerodynamic centre a=-0.3, inverse mass ratio, κ=0.05) …compared with data given by Zeiler * Good agreement. Divergence not calculated by Zeiler. Minor deviations for χα=0.2 at high ωh/ ωα * Zeiler, T.A., Results of Theodorsen and Garrick revisited, Journal of Aircraft Engineering Notes, 37(5):918-920, 2000.

  13. Conclusions and future work • Conclusions: • Development and validation of AdaptFoil2D, new panel code for deformable aerofoils • Mostly successful validation • Steady and unsteady aerodynamic and aeroelastic computations • Fast and reliable tool for evaluation of the aeroelastic performance of 2D aerofoils • AdaptFoil1D and AdaptFoil2D are suitable for design of aerodynamic control on wind turbine blades • Further work: • Extenssion of AdaptFoil2D to unsteady • separated flow and dynamic stall conditions

  14. www.cener.com

More Related