Research On Aerodynamic Performance And Structure Of Megawatt Lift-drag Hybrid Vertical Axis Wind Turbine

Compared to the horizontal axis wind turbine, the vertical axis wind turbine dispense with facing the wind. It’s a natural advantage. The energy utilization rate of lift type vertical axis wind turbine wind can reach the level of the horizontal axis wind turbine. But there are few high power vertical axis wind turbine. The main reasons for the large size of the lift type vertical axis wind turbine are difficult to start and difficult to design the structure of large size wind turbine. In order to solve this problem, this paper designed a new type of vertical axis wind turbine, which is a new type of megawatt lift-drag hybrid vertical axis wind turbine, and studied its aerodynamic performance and structure.Based on the double-multiple stream tube model for Darrieus vertical axis wind turbine, combined with the characteristics of lift-drag hybrid vertical axis wind turbine, considering the influence of lift blade and drag blade parameters, build multiplemultiple stream tube model by calculating in different areas to observe how those parameters affect aerodynamic performance and to calculate power factor of rotor with high efficiency.Since the theoretical model is difficult to consider the interaction between lift blades and drag blades, this paper established different lift-drag hybrid rotor model and studied the start performance, the operation efficiency and the stress on limit states by fluent numerical simulation method. The influence of two factors on the performance of the wind turbine is obtained, and the reason is analyzed. Compared to the traditional Darrieus vertical axis wind turbine, analyzed advantages and disadvantages of the liftdrag hybrid vertical axis wind turbine; the numerical simulation results are compared with the numerical simulation results, which verify the feasibility and applicability of the theoretical model.To solve the problem of megawatt vertical axis wind turbine structure, for 2MW lift-drag hybrid vertical axis wind turbine, compared a variety of rotor schemes and truss arm configurations, and ultimately selected a optimum scheme. This paper designed each beam of truss arm and the principal axis, and the internal structure, spreading material layer, connection mode of the lift blades and drag blades. This paper provided a set of complete and reliable rotor structure design scheme for megawatt lift-drag hybrid vertical axis wind turbine.ANSYS FEA was used to analyze the rotor structure, focused on the analysis on the stress and deformation of the structure under different conditions, and the structure of the inherent modal frequency and vibration type. Finally, this paper improved structure by comparing the calculation, so as to improve the safety.