Research On Characteristics Of Wind Turbine Blade With Extreme Wind Speed

As early as last century,the wind power boom has been lifted all over the world for the advantages of environmental protection,low consumption,renewable and so on.China’s wind power technology started late,but the speed of development is very fast.However,compared to the developed countries such as the United States,Denmark and other countries with wind power industry,there are still some deficiencies in China’s independent capability.Blade is an integral part of the wind turbine,and its performance will directly affect the operation time of the wind turbine and the benefits of the wind farm.The performance of the blade depends to a great extent on the performance of the airfoil.S8035 airfoil has better lift drag ratio,but it can not meet the demand of blade root strength.However,DU40 airfoil is thicker and can meet the requirements of blade root strength,but it has lost the lift drag ratio.This problem can be solved well by combining two kinds of airfoils.In addition,the blades are subjected to a variety of complex loads at the time of operation,and wind speed is a key factor affecting the blade load.Therefore,the determination of the influence of wind speed on the performance of blades has important reference significance for the design of blades.In this paper,a new airfoil is designed by combining two kinds of common airfoils.The blade model is established by using UG software,and the static and fatigue life analysis is carried out by using Ansys Workbench software.The following conclusions are obtained:1)Using XFOIL software to design composite airfoils,and compare the aerodynamic performance of the three airfoils.It is found that the aerodynamic performance of composite airfoils is better than that of DU40 airfoils and S8035 airfoils at the same angle of attack.2)The static analysis of three different types of FRP composite blades at different wind speeds is shown: Under the rated wind speed,the maximum equivalent stress of the blades of three kinds of glass fiber reinforced composites leaves appears at the root of the blade.The stress value is smaller;Under extreme wind speed,the maximum equivalent stress of three kinds of FRP composite blades appeared at the root of the blade.However,the dangerous zone extends the spanwise expansion of the blade,and the maximum equivalent stress is beyond the tensile strength of the blade.3)The static analysis results of three kinds of carbon fiber composite blades at different wind speeds are shown: Under the rated wind speed,the maximum equivalent stress of the three kinds of carbon fiber composite blades appears at the root of the blade.The stress value is smaller;Under the extreme wind speeds,although the maximum equivalent stress of the blades of the three glass fiber composites increases dramatically,but due to the superior properties of carbon fiber composites,the extreme wind speed has little influence on the performance of carbon fiber reinforced composites.4)The results of fatigue life analysis of three kinds of FRP composite blades are presented: The three airfoil blades can meet the requirement of 20 years running at rated wind speed,but the extreme wind speed will lead to a significant decrease in the number of running cycles of the three airfoils,and the service life will decrease sharply.Therefore,extreme wind speed is an important reason for decreasing service life of blades.Therefore,extreme wind speed is an important reason for decreasing service life of blades.