Method For Improving Road Traffic Wind Environment Based On Horizontal Axis Wind Turbine

Accidents such as rollover,sideslip,deflection,etc.are easy to occur when the driving vehicle is attacked by a strong crosswind.Keeping traffic safe under strong wind environment is an important way to maintain normal traffic operation.In engineering practice,passive wind protection devices such as wind barriers are widely adopted to reduce the wind speed on the road and improve the traffic wind environment.Wind-induced traffic accidents usually happen in areas with abundant wind resources,which is also a renewable energy source that can be fully utilized.Under the background and demands of single windproof measures and lowcarbon development,this paper presents a novel method to improve the road traffic wind environment based on horizontal axis wind turbines.Compared with the traditional measures to improve the traffic wind environment,the horizontal axis wind turbine can convert the kinetic energy in the incoming wind into electric energy for the use of road ancillary facilities,and at the same time,the wake with decreased wind speed behind the wind turbine can improve the traffic wind environment.This paper focuses on the improvement method of road traffic wind environment based on horizontal axis wind turbine,and carries out the following research work:1.The commonly used aviation airfoil NACA 2418 is optimized to obtain a low Reynolds number airfoil NEFU 6518 suitable for experimental scale.And the aerodynamic performance of optimized airfoil NEFU 6518 under different wind attack angles is analyzed by software Xfoil.The results show that compared with the basic airfoil,the lift coefficient of the optimized airfoil is greatly increased without deteriorating its lift-drag ratio.2.Based on the blade-element-momentum theory,the aerodynamic shape of low Reynolds number wind turbine blades is designed optimally.According to the results of aerodynamic shape optimization design,the airfoil coordinates are transformed in three dimensions,and the three-dimensional modeling of wind turbines with different blade numbers is obtained by introducing three-dimensional design software.The results show that the maximum wind energy utilization rate of the optimized three-blade wind turbine is over 35%,which is higher than that of the common small-scale wind turbine.3.With the number of blades of the wind turbine as the key,the large eddy simulation method based on Smagorinsky-Lilly model is adopted to numerically simulate the aerodynamic performance and wake characteristics of the small horizontal axis wind turbine and verified by wind tunnel tests,revealing the influence mechanism of the number of blades on the aerodynamic performance and wake characteristics of the wind turbine.The results show that the higher the number of blades of the rotor,the greater the velocity deficit and turbulence intensity in the near wake.In addition,the increase in the number of blades expanded the width of the near wake and promoted the transition from a W-shaped to a V-shaped wind speed distribution.Moreover,the number of blades significantly affected the stability of the tip vortex and hub/root vortex.4.The efficiency of small horizontal axis wind turbine in improving the traffic wind environment is evaluated.The effects of geometric parameters of wind turbine(number of blades)and incoming wind characteristics(wind speed and turbulence intensity)on the improvement of traffic wind environment are discussed.The results show that the key factor of improving the road traffic wind environment is the number of rotor blades.The influence of incoming wind speed and turbulence intensity on improving the road traffic wind environment is lower than that of the number of rotor blades.At the same time,the efficiency of improving the traffic wind environment of wind turbines with more blades is more sensitive to the incoming wind speed and turbulence intensity.This paper conforms to the requirements of green and low-carbon development of China’s highway network and strengthening the construction of safety protection measures.The results can provide reference for the development and design of integrated devices for improving road traffic wind environment and wind energy utilization.