Airfoil Geometry Parameters For Wind Turbine Blade Airfoil Influence Of Erosive Wear Characteristics

The dusty weather in the northwestern part of China is frequent.The wind turbines often operate in the gas-solid flow environment.The airflow of the sand will collide with wind turbine blades,which will cause the blades to wear and affect the aerodynamic and working life of the wind turbine.Based on the S809 airfoil,the wind turbine airfoil is modified by changing the geometrical parameters such as the leading edge radius,the modified length,the maximum relative thickness and its position,and it is developed by the numerical simulation method.The gas-solid flow and wear characteristics of the airfoil are studied.The influence of the geometrical parameters of the airfoil on the critical particle Stokes number range,flow field structure and aerodynamic performance of the airfoil begins to erode.The main findings are as follows:(1)The number of critical particle Stokes generated by the airfoil increases with the increase of the leading edge radius,indicating that the larger the radius of the leading edge of the airfoil,the less the airfoil is less likely to wear away.Compared with the small angle of attack(6.1°),at the large angle of attack(14.1°),the increase in the radius of the leading edge has a greater influence on the number of Stokes of the airfoil wear critical particles.As the radius of the leading edge increases,the flow separation point near the trailing edge of the airfoil moves backward,the pressure difference between the upper and lower airfoil increases,the lift coefficient increases,the drag coefficient decreases,and the aerodynamic performance of the airfoil increases.When the airfoil modification length is less than 15%,the value of the wear critical particle Stokes number of the airfoil is basically unchanged;and when the airfoil modification length is greater than 15%c,the wear critical particle Stokes number of the airfoil increases with it.(2)The larger the maximum relative thickness of the airfoil,the larger the number of critical particles Stokes that the airfoil wears,that is,the thick airfoil is less prone to erosion wear than the thin airfoil,and the airfoil wear at high angle of attack The rate of influence of the critical particle Stokes number increases.At the small angle of attack,when the maximum relative thickness of the airfoil increases to 31%c,the flow separation begins at the trailing edge,and the separation bubble appears.The pressure difference between the upper and lower airfoil decreases,resulting in a decrease in the airfoil lift coefficient and an increase in the drag coefficient.The lift-to-drag ratio is reduced.At the large angle of attack,as the maximum relative thickness of the airfoil increases,the airfoil flow separation is delayed,the differential pressure between the upper and lower airfoil increases,the lift coefficient increases,the drag coefficient decreases,and the lift-drag ratio increase.(3)As the maximum relative thickness of the airfoil is farther away from the leading edge point,the number of Stokes of the critical particles increases gradually,which improves the erosion resistance of the airfoil,and the airfoil trailing edge is at both the large angle of attack or the small angle of attack.Flow separation occurs,reducing the lift coefficient and reducing aerodynamic performance.Therefore,when designing an erosion-resistant airfoil,try to avoid changing the maximum relative thickness position of the airfoil.