Research On The Aerodynamic Characteristics Of Twist Type Vertical Axis Wind Turbines

The problems of Environmental pollution and energy shortage have attracted the national attention increasingly, developing clean and renewable wind energy can solve the problems. Vertical axis wind turbines (VAWT) have been paid more and more attention, because of its advantages of suitable for arbitrary wind direction and the simple structure. The important issues that need to be sloved are improving the starting performance of VAWT and the optimization of blade aerodynamic performance. In this thesis, a twist type VAWT was conceived, and its aerodynamic properties were researched. The paper mainly worked in the following aspects:1)According to the current development of wind turbines, improving starting performance should be as the key point of the development of wind turbines. Based on the early research, a designed plan that changing the traditional blade of VAWT into twist type VAWT was put forward.2)The NACA0018airfoil was selected as the basic airfoil of the3d modeling profile, the airfoil data was gotten through Profili airfoil and the2d basic model was built in CAD, finally the final3d model was finished through ProE. 3)In order to verify the good aerodynamic performance of twist type VAWT, the comparison was introduced between lift-drag type VAWT and traditional lift type VAWT. According to the airfoils of horizontal section by two types wind turbines are the same and straight blade VAWT of2d and3d numerical simulation results are basically the same, we only do two-dimensional airfoil numerical simulation and analyse the power coefficient in different working conditions.4)Provided the basis for the vorticity research of the twist type VAWT, this paper studyed VAWT for the tip speed ratio, compaction degree, and blade numbers of the simulated calculation. The results show that the vorticity have strong influence on blade.5)At last, we carried on the blade of twist type VAWT of numerical simulation, researched the best tip speed ratio in different numbers of blade and examined the high diameter ratio on the impact of power coefficient, meanwhile analysed the contours of vorticity, pressure and velocity about the simulated result. We draw a conclusion that the chord length is1000mm of3blade twist type VAWT in the tip speed ratio about2.15has the highest wind power utilization.Finally, under the same conditions, the power coefficient and starting performance of the three kinds of wind turbine’s optimal model were compared and analysied.The result show that twist type VAWT have not only high power coefficient but also good starting performance.Compared with lift-drag type VAWT of our team researched and traditional lift type VAWT, twist type VAWT have good starting performance and higher power coefficient.At the same time, the twist type VAWT are more beautiful,and more suit for installation in urban and rural dense populated areas.