Research On Aerodynamic Characteristics For S Series Airfoils Of The Straight-bladed Vertical Axis Wind Turbine

In order to investigate if S1046 and S809 airfoil blade are higher than NACA0018 airfoil blade in characteristics of starting and output.This article hammered at numerical computation and wind tunnel experiment,between asymmetric S809 airfoil and symmetric S1046 airfoil.The main research content are showed as follows:(1)Different airfoil wind turbine's output characteristics,including power coefficient characteristics and speed characteristics.The method is combine theoretical analysis and numerical calculation which will analysis different output characteristics of airfoil.I use numerical results to experiment and try to verify the accuracy of the data.Via the analysis of the flow field of feature points,it could conclude the reason for change of output characteristic among the three different airfoil wind turbines.(2)Different airfoil wind turbine's starting characteristics,including static moment coefficient characteristics and self-turn-on features.The method is combine theoretical analysis and numerical calculation which will analysis different azimuth's influence to static moment coefficient.I can use numerical results to experiment and try to verify the accuracy of the data.Under different wind speed in no load condition,self-turn-on experiment star on three different airfoil blades,in order to explore advantages and disadvantages of them,The main conclusions are showed as follows:(1)For output features:The three different airfoil with two blades and three blades wind turbine's power coefficient speed ratio increase first then have a downward trend.Under the same wind speed,when the tip speed ratio is higher than 1.2,the power coefficient of S1046 with two-wind-turbine blade airfoil is higher than other two kinds of blades.At tip speed ratio of 2.0,it achieve maximum power coefficient;when the tip speed ratio is higher than 1.0,the power coefficient of S1046 with three-wind-turbine blade airfoil is higher than other two kinds of blades.At tip speed ratio of 1.8,it achieve maximum power coefficient.Obtained by calculation flow chart shows that S1046 wind turbine airfoils internal flow field is relatively uniform,streamline is relatively smooth,it is improved in flow through and vortex inside the wind turbine blade tip.Meanwhile,two blades and three blades under different wind speed both the highest speed and starting time are higher than the other two airfoils.(2)For start features:When the wind speed is 10 m/s,static moment data analysis and wind tunnel experiment star by three different wind turbine airfoils in different azimuth.In general,asymmetric S809 airfoil has higher static moment coefficient.There are good consistency in wind tunnel experimental results and the numerical results,which further verify the accuracy of numerical calculation.Experiments show that two-blade and three-blade wind turbines' S1046 airfoil are superior to NACA0018 airfoil.Two-blade S1046 airfoil blade can start when wind speed is 6 m/s,S809 airfoil is 7 m/s,and NACA0018 airfoil is 9 m/s.Three-blade S1046 and S809 airfoil can start when wind speed is 6 m/s,and NACA0018 airfoil is 8 m/s.Through the method of numerical computation and wind tunnel experiments on three different airfoils to analysis output characteristic and starting characteristics,It comes to a conclusion that blade airfoil is more suitable for vertical axis wind turbines work environment and have higher output and starting characteristics.I hope it will contribute to other airfoil research.