The flow induced by plasma synthetic jet actuator was simulated through solving the Reynolds-averaged Navier-Stokes equations augmented by body force phenomenological plasma model.The effect of actuation frequency on the plasma synthetic jet was examined by case study.The numerical results present that with the actuation frequency increasing,the stream-wise distance of the adjacent vortex pairs induced by the actuator decreases monotonically,which is the same as the situation of the velocity fluctuations field caused by the vortex pairs.When the actuation frequency is 60 Hz,the vortex pairs formed during the adjacent actuation periods merge together quickly,and the flow structure in the downstream region is more close to that of the steady case.The actuation frequency has no visible influence on the time-averaged flow field of plasma synthetic jet.However,when the actuation frequency is relatively low(f<40 Hz),the momentum flux close to the actuator increases with the actuation frequency increasing,which is contrary to the situation in the far field from the wall.
A novel circulation control technique is proposed to overcome the shortcomings of blowing jet circulation control,which uses the synthetic jet as the actuator and avoids the limitation about air supply requirement.The effectiveness of synthetic jet circulation control to enhance lift of NCCR1510-7067N airfoil is confirmed by solving the 2-D unsteady Reynolds-averaged Navier-Stokes equations.The aerodynamic characteristics and the flow structure(especially close to the trailing edge) of NCCR1510-7067N airfoil at zero angle of attack are also presented to discuss the mechanism of lift enhancement of the airfoil with synthetic jet circulation control.The results indicate that the synthetic jet can effectively delay the separation point on the airfoil trailing edge and increase the circulation and lift of the airfoil by Coanda effect.The numerical simulation results demonstrate that the lift augmentation efficiency with synthetic jet circulation control reaches △CL/Cμ=114 in the present study,which is much higher than the value 12.1 in the case with steady blowing jet circulation control.
