Winglet size effect on the wake dynamics of model wind turbines

A laboratory investigation was conducted to evaluate the wake dynamics of model wind turbines with downwind-facing winglets of different sizes operating in a turbulent boundary layer (TBL). Particular focus is placed on exploring the like effect of the turbines under low-level jets (LLJs) with velocity peaks coincident with the top tip and hub heights. A standard rotor without winglets was included as a base case; the winglets spanned 0.096, 0.107, and 0.118 times the rotor radius. Results show that a larger winglet span enhances the energy fluxes in the far wake. Wake energy entrainment showed minor dependence on the winglet size for the turbine operating under LLJs. The work offers insight for strategic wind farm planning considering the modulation of TBLs and LLJs on turbines with winglets.