Study On Stall Characteristics Of Airfoil And Flow Control Of Synthetic Jet

The blade is the core component of wind power generation,and the airfoil is the basic unit of blade.Studying and improving the aerodynamic performance of airfoil is very important to wind turbine power generation efficiency and service life.The flow separation and stall problems at high angle of attack directly affect the aerodynamic performance of airfoil,what's more,in the actual operation process of wind turbine,due to the topography,atmospheric environment,the effect of the ground's boundary layer and so on,the velocity and direction of inflow in front of the airfoil often change over time,so the dynamic stall phenomenon is prevalent.As a kind of zero mass jet,synthetic jet has been widely used in the field of flow control in recent years.In this thesis,CFD numerical calculation method is used to study the stall characteristics of airfoil,including static stall and dynamic stall,then research the flow control effect of synthetic jet on stall flow field.The main contents are as follows:At first,calculate the static aerodynamic characteristics of S809 airfoil by CFD method,we can obtain the information of the critical angle of attack and so on.The flow separation control of synthetic jet is studied in detail,emphatically research the influences of jet position,jet deflection angle and jet frequency on the control effect under different angle of attack.Then,establish the oscillating motion model of airfoil,the flow field around airfoil under dynamic stall condition is numerically simulated by using sliding mesh method.The accuracy of the calculating results is verified by comparing with the experimental data.And the DMD method is used to analyze the unsteady characteristics of dynamic stall flow field and the influences of various motion parameters on dynamic stall,including the average angle of attack,the oscillating amplitude and the reduction frequency.At last,on the basis of the static stall,study the control effect of synthetic jet on the dynamic stall flow field.The jet conditions include single position jet and combined jet under two different positions.