| In the rapid development of modern community economy and industry,the use of energy was also changing.People were starting to re-examine traditional sources of energy like oil and coal.In addition,the aggravation of the pollution problem of the ecological environment has promoted the research of renewable energy.The wind energy as one of the new sources of energy which was attached to the governments of all over the world,then wind turbines were not only green and pollution-free,but the reserves of wind energy were far larger than those of traditional energy.The wind turbines which were working in complex atmospheres were often affected by dynamic stall will resulting in lower power generation efficiency and even safety accidents,In order to deepen the research of wind turbine stall,this article selected common S809 airfoils and Phase VI three-dimensional wind turbine blade as the research object,aimed at high wind speed of wind turbine blades made detailed simulation calculation problem of dynamic stall.In this paper,the basic theory of aerodynamics of wind turbine is described firstly,by using the S-A turbulence model,the lifting force hysteresis curves of CFD method and OSU experimental data are compared and verified which proves the feasibility of CFD method.Then the lift comparison and flow field of airfoil under different flow velocity are studied,and we choose high wind speed to study the variation law of lift lag curve of aerodynamic parameters such as folding frequency and oscillation angle of attack,and compare with the flow field of oscillating airfoil under high wind speed.By observing the changes in the flow field of the oscillating airfoil,we find that the flow of the wind is seriously separated which can easily lead to the damage of the blade of the wind turbine,it shows that the study of dynamic stall at high wind speed is of great significance to the actual operation and maintenance of the wind turbine.Secondly,the oscillating jets are added to the surface of the S809 airfoil and the dynamic stall calculation is compared with the two dimensional airfoil.The influence of jet position and size on dynamic stall is studied by changing the position of the slot and the pressure of the slot,and the pressure coefficient of the airfoil and the flow field distribution in the same oscillation period are analyzed.It is found that the oscillating jet can promote the development of the flow field and reduce the pressure load on the surface of the blade to prolong the service life of the wind turbine effectively.Finally,we use Solidworks to build a three-dimensional model of Phase VI blade based on S809 airfoil,and then simulate and calculate the dynamic stall problem of three dimensional blades under high wind speed.Then slicing the radial 30%,45%and 60%positions,and obtain the flow pattern of cross flow airfoils with different incoming wind speeds,the flow pattern of the cross section airfoil with different flow velocity can be obtained to explain the development law of the vortex in the dynamic stall flow field at high wind speed.The research on dynamic stall characteristics of wind turbine blades under high wind speed can provide theoretical basis for wind turbine design optimization and preventive maintenance in actual operation,and is conducive to popularize the application of wind turbines.Figure[33]Table[2]Reference[66]... |
PDF Full Text Request