Research Of Numerical Simulation Of Synthetic Jets Flow Fields

Flow control is the process of controlling the local flow around a moving body to change its aerodynamic and kinematic states. It is an attractive research field in fluid dynamics. It will play an important role in aircraft innovation and development in the future.Zero-net-mass-flux jets, also known as synthetic jets, are based on vortex kinematics. They are named as zero-net-mass-flux jets because no external fluid is included and the total net mass is zero when they entry and exit flow field. It is considered to be a new breakthrough of modern fluid dynamics as they have the unique advantage which transporting momentum external the fluid without mass transportation.This paper is mainly focus on 2D surface suction airfoils and co-flow jets airfoils. The grid block structure in the flow separation region is optimized, the principle of flow separation control is analyzed. The flow control of increasing airfoil lift is studied. The zero-net-mass-flux jets effect on airfoil lift/drag is evaluated based on different turbulence models, jet frequencies, jet velocity amplitudes and incoming flow attack angles. The principle of zero-net-mass-flux jets deflecting streamline can change the pressure distribution and increase airfoil lift is developed.The results prove that the airfoil lift-increasing general result of zero-net-mass-flux jets relates to jet velocity, jet frequency, incoming flow attack angle and etc. Zero-net-mass-flux jets could increase lift within the bound of stalling angle of attack and this effect decreases as the attack angle increases. The jet frequency effects on lift, drag, moment factor and lift-drag-ratio are non-linear when the jet amplitude is constant. The mean lift factor increases along with jet velocity when the jet frequency is constant. The aerodynamic forces of different jet frequency is closely related to jet velocity. The jet frequency effects under different jet velocity amplitude are strongly non-linear. The result of research is expected to provide helpful reference for the airfoil active flow control.