Effect of Vortex Generators on NREL Wind Turbine: Aerodynamic Performance and Far-Field Noise

Passive flow separation control with vortex generators (VG) is actively used over the wind turbine blade. In this paper, the effect of vortex generators is simulated on a full-scale 2-blade wind-turbine tested at the National Renewable Energy Laboratory. The simulation is performed using Very-Large-Eddy/Lattice-Boltzmann method (VLES/LBM). The analysis focuses on the effect of vortex generators on the aerodynamic performance and far-field noise. The simulation results without vortex generators are compared with the experimental results, reaching good agreement. The vortex generators produce counter-rotating vortices in the wake which effectively delay flow separation, leading to better aerodynamic performance. The acoustic analysis indicates that the dominant noise sources are the tonal noise produced by the flow separation and the turbulent-boundary-layer trailing-edge noise. Similar noise levels are obtained for the configurations with and without vortex generators.