Research On The Optimization Analysis Of Savonius Wind Rotor Based On CFD

Energy is an important foundation for economic and social development, and nowadays the world is faced with the rigid constraints from the depletion of mineral resources and the enormous pressure from global environmental pollution. To improve the structure of energy industry and develop renewable energy has attracted global attention all over the world. Wind energy is a kind of clean, non-polluting and renewable energy. Because of its abundant reserves and low development costs, wind energy will have a profound impact on the economic, social and environmental development with the reform of the structure of the energy industry.Wind power is currently one of the most mature technology to use wind energy, and vertical axis wind turbines are widely used in the field of small-scale wind power generation, among which Savonius wind turbines have attracted widespread concern because of its low start wind speed, small aerodynamic noise and good adaptability for wind direction. While the output torque of Savonius wind turbine changes periodically, and the periodic torque will cause changes in output power of the wind turbine which would lead to changes of voltage and frequency in the power system, meanwhile the periodic torque will generated frequent impact to the rotating shaft which would reduce durability of the wind turbine. Because it depends mainly on the difference between the positive toque and negative torque generated by the windward side to generate power, the torque coefficient (CT) of Savonius wind turbine is relatively low which results in the relatively low power coefficient (CP).The blades are one of the most important parts of wind turbine, to optimize the structure of blades would improve the performance of wind turbine in the maximum extent. In response to the above-mentioned shortcomings of traditional Savonius wind turbine, a twisted blade strategy was proposed in this paper to finish the mutate design of blades with the structural parameters of OL, AP, twist angle and radian of blades. Computational Fluid Dynamics was used to study the influence of different structural parameters on torque output performance of wind turbine. Firstly parametric modeling of wind rotor was finished based on the combination of Matlab and Pro/E, then the dynamic numerical simulation for the operation process of Savonius wind rotor was finished with the simulation platform of ANS YS workbench, the meshing strategy formulated by Meshing and the solving program generated by Fluent.Polynomial regression, orthogonal and interaction study was employed to arrange the tests of different structural parameters legitimately. Optimize distribution of structural parameters of the blade was determined after analysis and comparison of the torque output performance of the wind rotor under different parameters based on CT curve, extreme difference of CT and average CT, etc. The impact mechanism of different structural parameters to the torque output performance of wind rotor was analyzed through the flow field characteristics such as the pressure distribution and velocity vector distribution near the blades.Fluid-structure interaction analysis was introduced to analyze the mechanical property of Savonius wind rotor based on the stress distribution and strain distribution of the blades. Clapboard was designed as the auxiliary structure to improve the mechanical properties of twisted blades, the structural strength of which had been decreased after the structural changes. The distribution method of clapboards was established after optimization analysis based on the torque output performance of wind rotor. The mechanical property of blades with clapboards was verified through fluid-structure interaction analysis and the impact mechanism of clapboards was analyzed through flow field characteristics.Twisted blade strategy and auxiliary structure was adopted to optimize the torque output performance of Savonius wind rotor. Data and conclusions in this paper could provide data support for blade design of Savonius wind turbine in engineering applications to reduce workload and blindness of engineering design, and impact mechanism of structural parameters and auxiliary structure could provide theoretical support for the further studies.