Investigation On Influence Of Airfoils And Roughness On Aerodynamic Performance Of Wind Turbine Blade

Blade is the key component of wind turbine. In the northwest region of China, wind turbine is often used in the environment of sandstorm, the performance of blade is changed by the wind erosion. Therefore, the analysis which is about the influence of roughness on aerodynamic performance of blades has great significance. The paper is for roughness situation of airfoils, using the different blades as researching objects, carried out the research on the aerodynamic performance of blades.The paper designs 5 kinds of wind turbine blades of power 300 W. Selecting 5 kinds of airfoils, which are not sensitive to roughness, and suitable for the design condition.With Profili software and interpolation method, getting the complete data of lift coefficient and drag coefficient of airfoils. Adopting the optimization iteration procedure,calculated the chord lengths, torsion angles correction on the repeated, under the different rotational speeds, different wind speeds, studied the power, torque, thrust of rotors.Through the 1m two-dimensional model of the blade airfoils, defined consistent with theoretical calculations and simplify rough edge, with fluid analysis software of FLUENT,determined the roughness of quantization, the trailing edge of the rough that has a sensitive position. In the smooth and rough conditions of trailing edge, calculated the aerodynamic parameters distribution of 5 different blade airfoils with angles of attack, for analyzing the impact of different roughness and velocity field cloud picture.Calculation on the different aerodynamic of blades and sections, the study finds that:With speed incrementing, power and torque of the 5 wind turbine rotors change after the first drop of the law, maximum thrust of rotors are all within the range of speed600r/min-800r/min; Meanwhile, with the wind speed increasing, power of rotors increase,since the wind speed reaches 13m/s, the power decrease, 5 kinds of rotors’ turbulent layer thrust are 72.38 N.Through the study of roughness, the rough determined roughness,which can conform with the theory of fouling and formula to roughness quantify. The lift coefficients of blade airfoils are sensitive to the trailing edge of the rough at 10% distance section. The law of trailing edge of roughness makes the blade section lift coefficient increasing that is not universal. Roughness will cause the drag coefficient increase,lift-drag ratio decrease, FFA-W2-211, NACA4415, S822, DU-W2-250, SD2030 blade airfoils’ lift-to-drag ratio fell by 13%, 17%,11%,12%,15% respectively, when in the roughness of 0.008, 0.004, 0.008, 0.008, 0.01, the aerodynamic parameters change significantly. The trailing edge of the rough flows airfoils separation in advance, which has the certain stall condition.Comprehensive analysis, the wind turbine blade with initial airfoil S822 is the most suitable to the design condition and sand environment under low Reynolds number.