Aerodynamic Enhancement of Airfoils for Wind Energy Applications Using Active Fluid Gurney Flaps

Abstract

Abstract. Rising global energy demand underscores the need for more efficient renewable power generation, yet further expansion of wind farms is often constrained by geographical and environmental limitations. Enhancing the aerodynamic efficiency of individual turbine blades, therefore, represents a promising strategy to improve overall energy capture. This work investigates the aerodynamic performance of an active fluid Gurney flap (AFGF), a flow-control concept inspired by conventional Gurney flaps (GF) but employing trailing-edge jet injection to actively manipulate the pressure field. Unlike passive devices, the active fluid Gurney flap allows real-time control of aerodynamic loading through modulation of the injection pressure, enabling adaptive performance under different operating conditions. A two-dimensional computational fluid dynamics (CFD) framework was developed in ansysfluent to analyze the Active Fluid Gurney Flap on an S809 airfoil at a Reynolds number of Re=1×106. Unsteady Reynolds-averaged Navier–Stokes (URANS) simulations were conducted for three configurations: a clean airfoil, a conventional Gurney flap, and the proposed active fluid Gurney flap. The results show that the active fluid Gurney flap substantially modifies the pressure distribution by enhancing suction on the suction side and increasing diffusion on the pressure side. This redistribution leads to higher circulation and, consequently, a significant lift augmentation while maintaining controllable aerodynamic behavior. The findings demonstrate that the active fluid Gurney flap provides a flexible and efficient mechanism for aerodynamic performance enhancement, outperforming traditional passive high-lift devices. Due to its controllability and geometric reversibility, the active fluid Gurney flap represents a promising active flow-control strategy with potential applications in wind turbine blade design to improve aerodynamic efficiency and, by extension, their power output potential.