The Research On Dynamic Performance And Structure Optimization For Helical Vertical-Axis Wind Turbine

In recent years, wind energy is an efficient, clean and renewable energy source which has attracted more and more attentions. At the same time, the technologies of wind power generation have enormous potential for power generation in our country. Vertical axis wind turbine(VAWT) has been got a bright prospect in many small wind power generation for no yaw system, convenient to installation and maintenance, stable and reliable structure, the manufacturing cost is relatively low and many other advantages. For the wind turbine, how to start in low wind speed, improve the power efficiency, enhance the structure strength and stiffness and reduce the impact on the environment the problems confronted with all the researchers involved in this area. In this thesis, we study the helical VAWT. Firstly, we analyzed its dynamic performance and the flow field characteristics, secondly, simulated the statics and dynamics performance of the structural characteristics for the helical VAWT. This provided theoretical basis for the design and development of VAWT.The paper made a comprehensive study of the current situation and developing trend of the helical VAWT at home and abroad. After that we make it clear that our study should focus on improving the aerodynamic performance of the helical VAWT. Based on computational fluid dynamics theory, we simulated the lift and drag coefficient of NACA0012, NACA0015, NACA0018 airfoil by using the method of numerical simulation and selected airfoil of high lift-to-drag ratio as simulation. Then we analysed the influence of power coefficient in different blade numbers, different chord lengths and different tip speed ratio by means of two dimensional numerical simulation. Without considering three dimensional effect and high diameter ratio, we studied three dimensional helical VAWT aerodynamic performance based on two dimensional numerical simulation. In order to understand the structure performance of helical VAWT and according to the results of aerodynamic performance, we studied the overall structure design on the helical VAWT. At last, we use the Midas NFX software to analysed the structure of helical VAWT on static analysis, modal analysis and fatigue analysis. Provide theoretical guidance and suggestions for the structure optimization design of VAWT.