Research On Theaerodynamic Characteristics Of Wind Turbines Under The Three-dimensional Turbulent Flow

Aerodynamic performances of 750KW wind turbines were studied.The aerodynamic performances consist of establishment of aerodynamic model for wind turbines, analysis about aerodynamic characteristics of airfoil, aerodynamic performance analysis of wind turbine'rotor,the aerodynamic load calculation of wind turbine, aerodynamic analysis of wind turbine'wake and more.A wind turbine which is in the three-dimensional turbulent flow field was simulated according to the basic principles of aerodynamics, using CFD simulation analysis method and selecting the SST k-ωturbulence model. The purpose of the simulation is to analyse the aerodynamic performance of wind turbine.The analyses show many characteristics of wind turbine,such as pressure distribution around the machine, stall characteristics, load distribution on surface of blade, torque and force of wind wheel. Furthermore, changes of air flow around the blade airfoil was simulated under different wind speed and different angles of attack. The stall condition of airfoil under a large angle was accurately described. At the same time, the phenomenon of airfoil stall-delay is explained based on aerodynamics.Characteristics of the flow field where a wind turbine is working in were analysed. According to the analysis of interactions between wind turbine and air, tip losses and tower-shadow effect were explained.Then it was studied that hao the tower affects the aerodynamic performance of blade.The law that tower in different locations reacts on balde was summarized.Numerical simulation based on CFD methods was selected to calculate the loads on blade,which is a basis for the strength check of other parts of the wind turbine. Meanwhile, the aerodynamic characteristics of wind turbines'rotor wake was studied. Based on the simulation of a separate wind turbine's flow field,the research shows that the upriver wind turbine'wake has an influence up on downriver wind turbines. The research provides a basis for a reasonable layout of wind turbines in wind farm theoretically.