Dynamic characteristics and aerodynamic performance of vertical axis wind turbine
Gao Wei1,2, Li Chun1, Ye Zhou1, Nie Jiabin1
1.School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; 2.China Datang Group Creative Wind Energy Co.Ltd., Qingdao, Shangdong 266000, China
Abstract:The flow field of a vertical axis wind turbine(VAWT)is a typical unsteady large separation flow, which exhibits strong dynamic characteristics. Because of the complexity of aerodynamic perfor-mance for VAWT,it will result in more errors when common engineering algorithms is used to estimate VAWT′s performance. Firstly, the transient flow fields of four NACA symmetric airfoil series on H-type VAWT with different thickness were calculated based on the sliding mesh technique. And the relationship between airfoil dynamic stall and bound vortex generation and development were studied in detail. The range of phase angle when rotor dynamic stall occurs has been obtained and simultaneously the flow mechanism in the airfoil dynamic stall zone was explained preferably at the small tip speed ratio conditions. At the same time, the results also show that airfoil dynamic and static characteristics are very different for a running VAWT, thus the lift-drag coefficient calculation method has been proposed. Secondly, it was also been calculated that the changing trends of four airfoils blade torsion moment, wind electrical power and wind energy utilization coefficient change with the tip speed ratio. The results show that the thickness of airfoil for the blade torsion moment, wind electrical power and wind energy utilization coefficient has great influence. Therefore, the influence of geometry parameters on aerodynamic characteristics should be consided, such as airfoil thickness and rotary dynamic parameter for the design and development of H-type VAWT.
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