LES and FW-H Prediction of Aeroacoustic Noise for a SD 7037 Airfoil for Wind Turbine Applications

Abstract

The aeroacoustic noise generated by wind turbines poses issues with the implementation of this renewable energy technology. The use of a fully analytical model for predicting airfoil noise could serve as a crucial tool in the design phase of new turbines or noise reduction technologies. This work uses a combination of Large Eddy Simulation (LES) and the Ffowcs-Williams and Hawkings (FW-H) acoustic model to predict the noise generated by a 2D segment of the SD 7037(c) airfoil. The simulations are performed at a static angle of attack (AOA) and at a Reynolds number typical for small scale wind turbines of Re = 4.3×10⁴. The flow and acoustic results are validated against experimental results conducted by the Wind Energy Group at the University of Waterloo. This model was able to accurately predict the flow field and acoustic results for the 0° AOA, and determined the source of the 4.1 kHz tone to be 2D vortex shedding from the trailing edge (TE) and the 3.4 kHz tone to come from the transition from 2D to 3D boundary layer behaviour. The 1° AOA simulation, while able to simulate the flow and broadband acoustic spectra, requires further investigation to simulate the complex boundary layer transition behaviours required to predict the 3.4 kHz tone. Overall, this method proved to be an effective predictive tool for airfoil self-noise at static AOAs.