Study On The Aerodynamic Performance Of Vertical Axis Wind Turbine With Rough Belt

In recent years,under the dual pressure of energy depletion and environmental degradation,clean energy has received unprecedented attention,and then developed rapidly,especially the wind energy industry.The wind turbine is mainly divided into the horizontal axis and vertical axis.The vertical axis wind turbine can’t achieve large-scale commercial applications like the horizontal axis wind turbine,because of its low aerodynamic performance.However,the vertical axis wind turbine,with its unique advantages of no need for wind,simple structure,still attracts the attention of scholars at home and abroad.This paper focuses on the vertical axis wind turbine with NACA0012 airfoil.The angle between 0 °and 180 ° is the windward area of the wind turbine,and the windward area is the main working area of the wind turbine.In this area,the external surface pressure is greater than the internal surface pressure,which forms the lift force and promotes the blade to work.The rough belt is arranged on the external surface of the blade to slow down the air flow speed on the external surface of the blade,improve the pressure difference between the internal and external surfaces,and optimize the aerodynamic performance of the wind turbine.Through the combination of wind tunnel experiments and numerical simulation,the influence of rough belt on the aerodynamic performance of the wind turbine is analyzed.The following aspects are studied:(1)the rough belt is arranged in the range of 0.1 ～ 0.6C behind the outer surface of the airfoil,and the orthogonal test is designed with the installation angle,the height of the rough element and the ratio of the spacing height as three factors.The wind tunnel experiment is carried out,and the effect of the rough belt on the power of the wind turbine is intuitively obtained,and the optimal blade installation angle suitable for the rough belt is determined,which is more reasonable The ratio of the height of the rough element to the height of the spacing.(2)To accurately and systematically study the influence of rough belt on wind turbine,based on the results of wind tunnel experiment,a more reasonable and specific rough belt size is set up,the grid is verified to be independent,the calculation model is verified by the results of wind tunnel experiment,and then the numerical simulation calculation is carried out.(3)The change of torque coefficient and power coefficient under different tip speed ratios and the change of torque coefficient under different azimuth are calculated.Then the flow field under typical azimuth is analyzed to further clarify the internal mechanism of rough belt affecting the aerodynamic performance of wind turbine.(4)The torque coefficient of wind turbine is calculated under three different wind speeds in order to explore the influence of rough belt on the static starting performance of wind turbine.Then the internal mechanism of the flow field is analyzed.The results show that:(1)there is no obvious rule to follow in the ratio of pitch height,and the effect is better when the pitch height is larger;the effect is best when the height of rough element is 1 mm,and the effect of the height of rough element on the CP value of wind turbine is greater than that of pitch height.(2)Because the numerical simulation is carried out based on the wind tunnel experiment,the arrangement of rough belt can significantly improve the output characteristics and starting performance of the wind turbine,and the torque coefficient and power coefficient are improved to varying degrees when the wind speed is 6m/s,the starting torque of the wind turbine increases the most,(3)the pressure distribution and air flow on the upper and lower surfaces of the blade can be changed under the specific azimuth after the blade is arranged with the rough belt,so as to improve the utilization rate of wind energy,improve the output characteristics of the wind turbine under the azimuth,and then improve the aerodynamic performance of the whole wind turbine.In this study,wind tunnel experiment and numerical simulation are combined to explore the influence of rough belt on the aerodynamic performance of wind turbine.Meanwhile,the internal mechanism of rough belt lifting the output characteristics of the wind turbine is analyzed in combination with the flow field.It provides a new method to improve the aerodynamic performance of wind turbine by airfoil optimization.