Trailing Edge Noise Prediction of Wind Turbine Airfoils: A Benchmark Exercise

Abstract

This paper presents a trailing-edge noise prediction study of two state-of-the-art wind turbine airfoils, benchmarked against dedicated aerodynamic and acoustic wind tunnel experiments. Blind predictions were carried out by three institutes with long experience in trailing-edge noise simulation: the German Aerospace Centre (DLR), the Danish Technical University (DTU), and the Institute of Aerodynamics and Gas Dynamics (IAG) at the University of Stuttgart. Experimental data and engineering predictions were provided by Siemens Gamesa Renewable Energy (SGRE). While the aerodynamic predictions generally show good agreement, the acoustic results of the different codes exhibit substantial scatter, even in terms of relative sound pressure levels. This means that for industrial design decisions, where high accuracy is needed (<1 dB), evaluation of the trailing-edge noise for different airfoils still requires the combined application of measurement and simulation tools. Both techniques feature inherent uncertainties and scatter which currently cannot meet the targeted accuracy.