Numerical investigation of the flow control by a pulsed vortex generator jet on the turbulent flow of an airfoil

In this article, the flow separation control by the vortex generator jet actuator on an airfoil with NASA SC(2)-0714 cross-section in the flow with Reynolds 1×106 has been numerically investigated. The pulsed jet has a frequency of 40 Hz and a duty cycle of 50%. The simulation has been done at the angles of attack of 14, 16 and 18 degrees where the flow separation on the airfoil surface starts and then comes to a stall condition. In this research, in order to better understand how the pulsed vortex generator jet works, the effects of the unsteady jet on the instantaneous and time-averaged flow characteristics are extracted and the vortices pattern of the flow on the airfoil surface has been investigated. The results indicate that the actuation effectively delays the flow separation at the angles of attack of 14 and 16 degrees. As a result, the aerodynamic efficiency of the wing section increases by 14.8% and 33.2%, respectively. At the angle of attack of 18 degrees, which is in the post-stall condition, the actuation eliminates the massive flow separation and the flow attaches to the surface in a significant part of the airfoil chord.