The Effect Of Blade Wing Fence On Aerodynamic Performance Of Horizontal Axis Wind Turbine

The reserves of wind energy resources on the earth are very abundant,so in the development and research process of the wind turbine industry today,it is not difficult to find that many researchers have increased the utilization rate of wind energy through various ways and improved the aerodynamic efficiency of the whole wind turbine has also become one of the focuses that we urgently need to solve.One of the research directions that has attracted much attention is to add active flow control devices or passive flow control devices to wind turbine blades,such as trailing edge flaps,tip winglets,vortex generators,etc.,which have good improvement effects on the aerodynamic characteristics of horizontal axis wind turbines.The wing fence was first applied to the wing of an airplane to restrain the flow separation from the inner wing to the outer wing,so as to increase the safety performance of the airplane.The structure of blade wing fence is simple and has little influence on the structure of blade.Therefore,it is proposed to apply wing knife to horizontal axis wind turbine in order to improve the aerodynamic performance of wind turbine.In order to study the influence of adding blade wing fence on the aerodynamic characteristics of horizontal axis wind turbine,this work will use NREL 5MW large horizontal axis wind turbine model published by the U.S.Renewable Energy Laboratory as the basic comparison model,and analyze its influence on the aerodynamic characteristics under different working conditions compared with the basic model by adding blade wing fence with different configuration parameters to the basic model.The main contents and conclusions of this work are as follows:Firstly,the grid independence and the calculated and experimental values of wind turbine torque and axial force are compared and verified to ensure the accuracy and accuracy of the numerical simulation method within the allowable error range.CFD method was used to calculate and analyze the aerodynamic performance of the foundation model of 5MW horizontal axis wind turbine under different working conditions.We can obtain that with the continuous increase of the incoming wind speed,the flow on the blade pressure surface basically does not change,while the flow separation area on the suction surface is increasing,and the spanwise flow from the blade root to the blade tip is increasing.At the same airfoil section,the flow separation tends to approach the leading edge as the incoming wind speed increases.Secondly,a common wing fence with different configuration parameters is installed on the basis of the original model of the 5MW wind turbine.On the premise of keeping the thickness of the wing fence unchanged,the main considerations are spanwise position(r=5m,r=9m,r=13m,r=17m),installation angle(0°,+30°,-30°)and height(h=0.1m,h=0.2m,h=0.3m)and other parameters to study their influence on the aerodynamic performance of the wind turbine.Through numerical simulation calculation and analysis,we can draw the following conclusions: when the thickness,height and installation angle of wind turbine blade wing fence remain unchanged and only the spanwise installation position is changed,the wind energy utilization coefficient of wing fence installed at r=9m is obviously improved;On the previous basis,when the thickness,position and installation angle of the wing-shaped fence are kept unchanged and only the height of the wing-shaped fence is changed,the power increases when h=0.2m,while the rest shows a downward trend.Based on the determination of the first two parameters,only the installation angle of wing-shaped fence is changed,and it is found that the installation angle is the best at 0°.Finally,the shape and number of wing fences are numerically simulated.Firstly,the shape of wing fences is changed,and the influence of arc wing fences on the aerodynamic performance of wind turbine is studied.The results show that compared with simply changing the installation angle of ordinary wing fences,the effect of arc wing fences on the wind energy utilization coefficient and output power of wind turbine is more obvious.Secondly,referring to the sawtooth wing fence model on the plane,it is applied to the wind turbine blade.The results show that the leading edge sawtooth wing fence has limited effect on improving the aerodynamic performance.Thirdly,on the basis of the wing fence parameters determined in the previous chapter,whether the double-wing fence can have more obvious lifting effect than a single common wing fence is studied.The calculation results show that the number of wing fences is not as large as possible.In this work,the effects of blade airfoil fences with different configuration parameters on the aerodynamic characteristics of horizontal axis wind turbine are compared and analyzed respectively.It is shown that blade airfoil fences do improve the aerodynamic performance of horizontal axis wind turbine,and a more ideal installation scheme of blade airfoil fences is obtained through calculation and analysis,which provides a certain reference for future application in products.