Research Of Improving Aerodynamic Preformances Of Wind Trbines Balade Profile

With the maturation of the developments in related technologies and expansion of its scales, high speed developments of wind turbines make greater demands on its aerodynamics performances. So far the flow control is the most popular method in the area of optimizing blade of wind turbines. The active and passive flow control is adopted separately in dealing with the optimization of the corresponding blades.The wind turbines blade profile which intercepted from the 3.6MW wind turbines with a 18 cm distance from the root of the blade have been truncated from the trailing with a 10 percentage along the direction of strings by the method named Wortaman, and finally the blunt-trailing baled is obtained. On the basis of the blunt-trailing, airfoils with square and triangle serrated trailing edges are obtained with the scale h/?=4 by reference to the noise-canceling wind turbines. Airfoils with the serrated trailing edges and without any trailing edges extensions are studied at various working conditions which conducting the k-? model of RNG of numerical simulation in dealing with the influence of different serrated trailing edges on aerodynamic performances including the coefficient of lift, drag and moment and the results are analyzed and compared. It is found that the serrations with different shapes can improve the lift of the airfoil with a certain extent. When it comes to the improving of the aerodynamic performances, the triangle was superior to others with a limitation on manufacturing process. The square one has the advantages of the both the high strength and tractable.Numerical simulations of various working conditions around the airfoils by adding stationary air suction which its length ranges 1%~10% of the chord with a suck pressure ranges-50Pa~-500 Pa at the separation point are made under the situation that the the Spalart-Allmaras model applied. It is found that the coupling of the main flow and the stationary air suction have a great effect on the improving of the lift. The input of the local energy promotes the changes of the global flow and earn the control effect that suspend stall and delays the separation.On the basis of the outcomes of steady flow field, Spalart-Allmaras model is subjected to the unsteady one to simulate to investigate the influence of steady suction air on the of mechanism of shedding of the leading and the trailing edge vertexes and the pressure coefficient. The results show that the coupling of steady suction air and the mainstream of flow field can effectively improve the profile performances. Steady suction effectively control the flow separation,reduced the leading edge separation vortex and the size of the tail edge vortex separation, so as to reduce fluctuations increase stability. Steady suction hardly influenced on the resistance.