A numerical investigation of synthetic jet effect on dynamic stall control of oscillating airfoil

At high angles of attack, the dynamic stall phenomenon could be appearing owing to the vortex shedding particularly in an oscillating airfoil. The consequences of this event are a considerable decrease in the lift and an increase in the drag as well as the pitching moment coefficients. The flow was assumed to be unsteady and turbulent at a Mach number 0.2 and for Reynolds number 1million. This research was done for a range of angle of attack 15o±10o. In order to carry out the numerical analysis of the problem, the 2-D compressible turbulent Navier-Stokes equations based on “Roe” scheme with second-order accuracy were solved. Turbulence modeling was carried out using the three-equation k-kL-ω model. Regarding the obtained results, it was observed that this flow control method had a significant ability in eliminating the dynamic stall. It was also revealed that the phase difference between the jet and airfoil oscillations is more affected by the dynamic stall decrement. In these changes, use of the SJ with 0.1 momentum coefficient, led to the highest amplitude of lift at φ=-30°, and the multiplication of drag amplitude and amplitude of moment coefficient at φ=-10° offered the best performance in addition to the considerable decrease.