Research On Flow Field And Tip Vortex Control Of Horizontal Axis Wind Turbine

In order to study the characteristic of complicated three-dimensional and rotating flow field ofwind turbine, in this paper, the flow field is deeply analyzed via numerical simulation. And furthermore, the winglet is applied to control the tip vortex properly.This paper is based on the pressure distribution of the two-dimensional airfoil which is affectedby the angle of attack and Reynolds Number(inflowing velocity). The results show that the pressuredistribution is sensitive with the angle of attack, especially on the leading edge before flow separation.While the pressure distribution changes entirely by comparison with the inflowing velocity changing,of course including the trailing edge. Thus, the angle of attack can be confirmed by the pressuredistribution under the same flowing condition.The upstream and downstream velocities vary periodically along circumferential direction andare affected by the parameters and wake flow of the blades. A new approach is introduced to judge theaerodynamic performance. It shows that the pressure distribution of central section of the bladescoincides well with that of two-dimensional airfoils. While the pressure of the root especially theblade tip, which accounted for3.3%of the total blade length, is seriously destroyed by the tip vortex.Finally, a kind of winglet is designed to waken the tip vortex. The result shows that the pressuredistribution is approved and is even closer to that of the two-dimensional airfoil. Further more, theaerodynamic performance and efficiency are boosted, the tip vortex dissipates quickly, and highquality flow is provided for the downstream wind turbine in the wind field.