Evaluation of Several Wind Turbine Trailing-Edge Aerodynamic Brakes

An investigation was undertaken to identify the aerodynamic performance of five separate trailing-edge control devices and to evalutate their potential for wind turbine overspeed control applications. A modular two-dimensional wind tunnel model was constructed and aerodynamic performance data were acquired. To further interpret their potential, the controls were evaluated using a performanceanalysis computer program and a generic wind turbine geometry. On the basis of the investigation results, the Spoiler-Flap control configuration was deemed best suited for turbine braking applications. This particular control exhibited a good suction coefficient behavior over a broad angle-of-attack range and good turbine braking capabilities, especially at low tip-speed ratios.