Numerical Simulation Of Airfoil Flow Channel Aerodynamic Performance

As fossil energy dries up,the wind energy is increasingly concerned with its clean and renewable advantages.The vertical shaft wind generator group is concerned by the researchers because of its unique structure and good wind energy utilization coefficient development space.This paper improves the original wing type of the vertical shaft wind machine,and makes the wing type into an open runner airfoil.Based on this,this paper analyzes the combination torque and the comprehensive performance of the original wing and improved wing type,and compares the performance of the original wing and the open runner airfoil,and finally analyzes the comprehensive performance on vertical shaft wind generator with the original wing and the open runner airfoil.In this paper,the wind turbine is analyzed firstly,and the horizontal axis wind turbine and the vertical axis wind turbine are introduced,and the advantages and disadvantages of the two kinds of wind turbines are compared,and the research status is excavated.Vertical Axis Wind Turbine is a device that converts wind energy into electrical energy.At present,the main problems of horizontal axis wind turbine are low utilization coefficient of wind energy and poor self-starting performance.In this paper,a kind of vertical axis wind turbine with good starting performance and high wind energy utilization coefficient with low tip speed ratio is introduced,so that the vertical axis wind turbine can be used in urban area.Then,the theoretical analysis of airfoil and wind turbine is carried out by using the basic theory of hydrodynamic fluid and wind turbine,which provides a theoretical basis for numerical simulation.In this paper,the NACA4415 is based on the airfoil,the flow channel is opened on both sides of the NACA4415 airfoil,and the bezel with automatic opening and closing can be set on the front end of the airfoil to realize the switching of the lift type wind turbine and the resistance generator,and improve the comprehensive performance of the wind turbine.By using Fluent software,the flow state of the rising resistance airfoil and the NACA4415 airfoil of the runner under different tip speed ratio,wind speed and angle of attack are numerically simulated,and the vertical axial wind turbine composed of the two airfoil is numerically simulated,and the first length quadrilateral structure mesh is adopted at the outer boundary of the airfoil.The mesh around the airfoil can be divided into dense way,and the mesh is loosely divided from the distance.The inner channel of airfoil adopts triangular unstructured mesh,and the triangular mesh has good applicability and can adapt to irregular shape,so as to improve the simulation accuracy and reduce the analog amount.Considering the characteristics,calculation accuracy and calculation time of the fluid,this paper selects the Spalart-Allmaras model and the RNG k-? model to simulate the airfoil statically.According to the simulation results and the analysis of mechanics theory,the results show that: The lifting resistance airfoil is superior to the NACA4415 airfoil in self-starting performance,and the wind energy utilization coefficient is better than the NACA4415 airfoil in the low tip speed ratio range,but the wind energy utilization coefficient is worse than the NACA4415 airfoil in the high-tip speed ratio range,and the change of airway angle will affect the aerodynamic characteristics of the rising resistance airfoil.The lift resistance airfoil with an airway angle of 15 degrees has the best aerodynamic characteristics.When the vertical axis wind turbine is applied to the urban power generation,the lifting resistance airfoil has greater advantages and prospects.