Effect of orifice inclined angle on flow control of the stalled airfoil with synthetic jet actuator

Numerical simulation on effect of orifice inclined angle on separation flow control of the stalled NACA0015 airfoil was carried out by the Reynolds averaged Navier-Stocks equations solved with Fluent 6.1 at the high angle of attack (α=20°), i.e. orifice inclined angle relative to synthetic jet actuator locates in recirculation region of the airfoil. The calculated results demonstrate that the optimum orifice inclined angle is 30 degree for the synthetic jet controls the separated shear layer of the airfoil, which means the jet points to the stream-wise flow direction and is very close to the wall; at the inclined angle, lift coefficient of the airfoil increases by 5% compared with that with vertical jet flow control, meanwhile, drag coefficient of the airfoil decreases by 15%. The mechanism of the enhancement flow control effect at lower orifice inclined angle was also revealed by analyzing the vortex structure separated from the airfoil and the flow field near the actuator orifice.