Numerical study on aerodynamic performance and noise of wind turbine airfoils with serrated gurney flap

Improving the airfoil aerodynamics of wind turbines is an effective way to raise the wind energy utilization rate and reduce the dependence on fossil fuels. Select a NACA0018 airfoil as a baseline, and a novel serrated Gurney flap (SGF) is proposed to promote the aerodynamic performance of the airfoil. The SST k-omega turbulence model and large eddy simulation are used to numerically simulate the performance of airfoils with Gurney flap (GF) and SGF. The influence of serration geometry parameters on aerodynamics and noise is examined, and the vortex structure is explored to reveal the inherent mechanism. The results show that the SGFs can significantly improve lift coefficient, delay the stall, and greatly reduce the acoustic noise at investigated attack angles. The arrangement of SGF enhances the stability of shedding wakes and lowers the energy losses, leading to better aerodynamic performance and lower noise. ASGF-0.8-6.7 is a preferred scheme for raising airfoil performance with an enhanced lift-to-drag ratio of 8.61%, a delayed attack angle of the stall of 3 degrees, and a maximum noise reduction of 10.2 dB in the radiated noise, compared to the baseline.