Can vortex generators reduce power losses of utility-scale wind turbines due to blade leading edge erosion?

Vortex generators (VGs) improve the aerodynamic performance of airfoils by increasing the angle of attack at which stall occurs at the expense of a small increase in profile drag. This study explores the potential of VGs to reduce wind turbine power and energy losses due to blade leading edge erosion. A 22 MW turbine, with blades assumed to be affected by different levels of leading edge erosion, is considered. Erosion is considered over the outer blade region, featuring a 21% thick airfoil. The turbine performance from cut-in to cut-out wind speed is determined with turbulent aero-servo-elastic simulations. The curves of lift and drag coefficients of the outboard airfoil with and without erosion and with and without VGs are determined using Reynolds-averaged Navier-Stokes Computational Fluid Dynamics. Two offshore and one onshore sites are considered. VGs are found to start alleviating power and energy loss due to erosion only once erosion has reached advanced stages, corresponding to removal of the protective coating and initial damage of the composite substrate. For any given erosion level, the performance benefit of VGs is found to be more significant at the onshore site.