Final results from the EU project AVATAR

Aerodynamic modelling of 10 MW wind turbines

Journal article (2018)

Authors

J.G. Schepers ECN Solar Energy
K Boorsma ECN Solar Energy
Carlos Ferreira Wind Energy - Aerospace Engineering
B Stoevesandt Fraunhofer IWES
G. Barakos University of Glasgow
A. Croce Polimi
J. Madsen LM Wind Power
NN Sorensen Technical University of Denmark (DTU)
V. Voutsinas National Technical University of Athens
G Sieros National Technical University of Athens
H. Rahimi Fraunhofer IWES, ForWind
E. Jost University of Stuttgart
T. Lutz University of Stuttgart
T. Maeder GE Global Research - Europe
Research Group
Wind Energy (Aerospace Engineering) (TU Delft)
Copyright: © 2018 J.G. Schepers, K. Boorsma, N. Sorensen, V. Voutsinas, G. Sieros, H. Rahimi, H. Heisselmann, E. Jost, T. Lutz, T. Maeder, A. Gonzalez, Carlos Ferreira, B. Stoevesandt, G. Barakos, N. Lampropoulos, A. Croce, J. Madsen
DOI: https://doi.org/10.1088/1742-6596/1037/2/022013
More Info
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Published Date

19-06-2018

Language

English

Faculty

Aerospace Engineering

Department

Flow Physics and Technology

Research Group

Wind Energy

Abstract

This paper presents final results from the EU project AVATAR in which aerodynamic models are improved and validated for wind turbines on a scale of 10 MW and more. Special attention is paid to the improvement of low fidelity engineering (BEM based) models with higher fidelity (CFD) models but also with intermediate fidelity free vortex wake (FVW) models. The latter methods were found to be a good basis for improvement of induction modelling in engineering methods amongst others for the prediction of yawed cases, which in AVATAR was found to be one of the most challenging subjects to model. FVW methods also helped to improve the prediction of tip losses. Aero-elastic calculations with BEM based and FVW based models showed that fatigue loads for normal production cases were over predicted with approximately 15% or even more. It should then be realised that the outcome of BEM based models does not only depend on the choice of engineering add-ons (as is often assumed) but it is also heavily dependent on the way the induced velocities are solved. To this end an annulus and element approach are discussed which are assessed with the aid of FVW methods. For the prediction of fatigue loads the so-called element approach is recommended but the derived yaw models rely on an annulus approach which pleads for a generalised solution method for the induced velocities.