Study On Aerodynamic Characteristics Of Vertical Axis Wind Turbine With Guide Vane

At present,the deterioration of ecological environment and the crisis of energy supply had become the two major issues of universal concern in the world.China has put forward the plan of carbon peak and carbon neutral,and the development of environment-friendly renewable energy was an important means to achieve this goal.Wind energy was one of the most commercially successful renewable clean energy sources.With the rapid popularization of large-scale wind power generation,more and more attention has been paid to the use of small and medium-sized wind energy,especially in agricultural and pastoral areas and remote areas.And improving the efficiency of small and medium-sized wind turbines has become a major research direction in this field.In the small and medium-sized wind energy utilization,vertical axis wind turbine occupies a certain market,and there was a great space for development.Among them,the straight-wing vertical axis wind turbine has received extensive attention for its simple structure,easy maintenance,no need for wind devices and other characteristics.However,it also has some shortcomings,such as poor self-starting performance and unsatisfactory aerodynamic performance at low wind speed and low tip speed ratio.Therefore,this paper designed a linear Guide vane installed around the wind wheel of the vertical axis wind turbine with linear wing,to improve the wind speed into the wind wheel,improve the flow around the wind wheel,so as to improve its static and dynamic aerodynamic performance.In this paper,the numerical simulation and wind tunnel test were combined to study and analyze the influence of main structural parameters of the Guide vane on the aerodynamic performance of the straight-wing vertical axis wind turbine.Under the conditions of this study,a group of optimal structural parameters of the Guide vane were obtained,and a prototype was designed and processed.The experimental research was carried out.The main research contents and results were as follows:(1)on the basis of the prototype and wind tunnel size determine the main geometric parameters of Guide vane,and encoding the parameters,and USES the quadratic orthogonal rotation combination test design method,through the two-dimensional numerical simulation method,to calculate the diversion type wind turbine with different parameter combination average starting torque,find the optimal structural parameters of Guide vane.The width of the Guide vane,the distance between the Guide vane and the wind wheel,and the rotation Angle of the Guide vane relative to the normal were taken as the test factors.The optimal geometric parameter combination of the Guide vane was obtained: the width of the Guide vane was 180 mm,the distance from the wind wheel was 92 mm,and the rotation Angle was-9°.(2)The numerical simulation results of the flow field around the wind wheel of the wind turbine with and without the Guide vane were compared and analyzed.The results show that: The Guide vane has an obvious acceleration effect on the airflow in the flow passage of the wind turbine,which improves the velocity fluctuation between the Guide vane and the blade and affects the pressure distribution around the blade,mainly including the increase of the overall velocity of the flow passage and the reduction of the low-speed zone around the blade.(3)According to the better Guide vane parameters obtained by numerical simulation,a machining prototype was designed and a wind tunnel test was carried out.By comparing the static and dynamic aerodynamic characteristics of the wind turbine with the Guide vane and the non-guide wind turbine at different wind speeds,the aerodynamic performance of the wind turbine with the Guide vane with better structural parameters was analyzed.Results show that after adding Guide vane static start of straight blade vertical axis wind turbine performance was improved,the higher the wind speed,the diversion threatening the straight blade vertical axis wind turbine static startup performance improvements,the better,under the 10 m/s wind speed,wind machine with a Guide vane was no Guide vane wind turbine in a quarter cycle start torque coefficient can be increased by 35.6% on average.The Guide vane can not only improve the static start characteristics,but also improve the dynamic start characteristics to a certain extent.The effect of the Guide vane on the average output power coefficient of the wind turbine increases with the increase of the wind speed,and the maximum effect can reach 14.43%.The Guide vane can improve the maximum speed of the wind turbine greatly at low wind speed,but it can improve the maximum speed of the wind turbine less at high wind speed,but it can accelerate the speed of the wind turbine,so that the wind turbine can reach a stable speed faster.The linear Guide vane designed in this paper can effectively improve the self-starting performance and aerodynamic characteristics of the straight-wing vertical axis wind turbine at low rotational speed.This study can provide a basis for improving the aerodynamic performance of the straight-wing vertical axis wind turbine by installing the Guide vane,and provide a reference for developing small and medium-sized wind energy utilization system.