Numerical Simulation Of Large Wind Turbine Blade Vortex Generator Flow Control

In recent years,wind turbines have been gradually enlarged,and the length of wind turbine blades has exceeded 100 meters.In order to ensure the structural strength of the blade,a large-thickness airfoil is often used at the root of the blade.Due to the poor aerodynamic performance of the large-thickness airfoil,surface flow separation is prone to occur and the power coefficient of the blade is reduced.Therefore,flow separation on the blade surface is suppressed by installing flow control methods such as vortex generators.It can increase the wind turbine output power.It is of great significance to increase the wind farms economic effect.However,there are few studies on vortex generators influence to the airfoils and blades aerodynamic performance under rough walls.At the same time,the vortex generators influence on blade loads under extreme wind conditions is not considered.Therefore,this paper focuses on vortex generators and rough wall influence on the airfoil aerodynamic performance and the vortex generators influence on the blade load distribution under extreme wind conditions.Its influence law and flow mechanism have been ascertained.First,obtain the lift-drag distribution of the DU30 airfoil with or without vortex generators and different wall conditions,through wind tunnel experiments and numerical calculations.The flow field distribution and flow mechanism are explored through numerical calculation results.Second,establish a numerical calculation model for a commercial wind turbine blade.Numerical calculations are carried out for vortex generators installation and different wall conditions.And the flow mechanism is explored through the flow state distribution on the blade surface.Third,wind tunnel experiments were carried out on the load distribution of the DU30 airfoil under the full angle of attack by installing the vortex generator.The research shows that the vortex generator has little influence on the load when the trailing edge is facing the wind,and the average load is lower than that of the leading edge facing the wind.Finally,the wind turbine blade load is calculated within the range of360° pitch angle.It is concluded that the trailing edge upwind has a better load reduction advantage.The distribution law and flow mechanism of wind turbine blades and airfoils aerodynamic characteristics by the vortex generators proved in this paper.It can provide data support and theoretical basis for relevant optimization design.This paper proposes a windward load reduction strategy for the trailing edge of wind turbine blades under extreme wind conditions.It can further reduce the blade load,improve the safety and stability of the unit,and provide a certain reference value for engineering applications.