Experimental Investigation Of Lift Enhancement For Airfoil Using Plasma Actuators

With the rapid development of aviation transport industry,the performance requirements of lift devices are increasing.Flow control technology can increase the circulation in lift devices and thus improve the lift.Dielectric barrier discharge(DBD)plasma flow control technology is a new technology developed in recent years,which can effectively improve the aerodynamic performance of lift devices.In this paper,DBD plasma actuators are arranged on the trailing edge of airfoil to achieve the lift-enhancement.The plasma actuator arranged on the surface of the airfoil can have different thicknesses and in order to study the influence of actuator thickness on the boundary layer of the airfoil a flat-plate model with a convex thin plate is implemented.By means of theoretical analysis and numerical simulation,a fitting solution relating the thickness of the thin plates,Reynolds number,and the growth rate of the boundary layer thickness is found.The fitting solution matched closely with the numerical solution.The actuator is placed on the trailing edge of NACA0015 airfoil,and then the effect of plasma actuation on the lift performance of this single-element airfoil is studied.The influences of the actuator position,actuation intensity,and inlet velocity on the lift are obtained.The experimental results show that the lift coefficient can increase by 10% with plasma actuation on the trailing edge and when the plasma actuation is applied on both the upper and lower surfaces of the trailing edge,the lift-enhancement is the most obvious.The lift coefficient has an optimal frequency range where it increases the most.Increasing the voltage or decreasing the inlet velocity can improve the lift-enhancement.Several conclusions can be drawn from the plasma actuation experiments of a two-element airfoil with a flap of 30°.The lift coefficient can increase by 13% by applying plasma actuation simultaneously on the upper and lower surfaces of the flap.The analysis of different parameters through experimentation indicates that the actuation frequency and voltage are important factors affecting the lift.When the angle of attack is large,the lift-enhancement of the two-element airfoil is not as obvious as that of the single-element airfoil.The plasma actuation method of circulation enhancement for the two-element airfoil is more effective at a small angle of attack.The lift-enhancements of single-element airfoil and two-element airfoil are realized by plasma actuation.The optimal solution of actuation parameters is proposed.The research provides a reference for the lift-enhancement of airfoil using plasma aerodynamic actuation.