High-resolution direct numerical simulations of flow structure and aerodynamic performance of wind turbine airfoil at wide range of Reynolds numbers

The objective of this study is to develop direct numerical simulations (DNS) investigate the aerodynamic performance, transition turbulence, and capture laminar separation bubble occurring on a wind turbine blade. Simulations are conducted with spectral/hp element method details flow over blades NACA-4412 airfoil at wide range design parameters. This chosen because recent studies have shown that it challenging instabilities pressure fluctuations in separated shear layer turbines by experimental methods. Furthermore, owing more accurate development DNS, bubbles high Reynolds numbers captured. results show vortex structures shed from trailing edge raising angle attack (α). Consequently, fully turbulent develops downstream (Karman vortex). Moreover, fluctuation significantly increased α. However, some rolling up structures, similar Kelvin–Helmholtz rolls, surface near edge, observed α>12°. point was delayed Xsep/C = 0.19 0.58 decreasing α 16 0 Re 5 × 104.