Active Fluid Gurney Flaps, Controllable Lift Enhancement Toward Wind Turbine Power Production Regulation

ABSTRACT Meeting the rising demand for renewable energy requires innovative solutions to enhance wind power extraction, particularly given demographic and geographic constraints on wind farm deployment. Active high‐lift devices, such as the Active Fluid Gurney Flap (AFGF), offer a promising approach that can dynamically modify aerodynamic performance to optimize power generation. Unlike conventional passive mechanisms, the AFGF enables real‐time lift control through adjustable jet flow pressure, overcoming the limitations of traditional Gurney Flaps. This study employs a two‐dimensional computational fluid dynamics (CFD) model in ANSYS Fluent to evaluate the aerodynamic performance of the AFGF across a Reynolds number range of to and angles of attack between −20° and 20°. The computational model is validated against experimental data for an NREL S809 airfoil. Comparative analyses are conducted between a baseline airfoil, configurations with traditional Gurney Flaps, and the proposed AFGF design. Positioned on the pressure side of the trailing edge, the AFGF enables controlled air injection at a constant total pressure level. Unsteady Reynolds‐Averaged Navier–Stokes (URANS) simulations reveal that the AFGF enhances lift by increasing expansion on the suction side while diffusing the flow on the pressure side, improving circulation around the airfoil. As an active high‐lift device, the AFGF enables aerodynamic forces real‐time modulation by adjusting jet's injection pressure, allowing more efficient energy extraction and load control in wind turbines under different conditions. The resulting lift augmentation boosts power generation, with the energy gain surpassing the jet generation cost for various operating conditions. Additionally, the AFGF preserves the airfoil's original geometry when inactive, maintaining aerodynamic efficiency and adaptability.