Effects of Simultaneous Suction and Blowing over an Airfoil on Flow Behavior and Aerodynamic Coefficients

In this study, the simultaneous effect of suction and blowing on the boundary layer and the effect of control parameters on the flow separation from a NACA ۰۰۱۲ airfoil is numerically analyzed. Reynolds number is considered ۵۰۰۰۰۰ , and the shear stress transport (SST) k-w turbulence model is used to estimate eddy viscosity. The airfoil is supposed to be ۲-D. To validate the numerical results, they were compared with reported experiments. In the flow control by simultaneous suction and blowing, the location of the suction jet was ۰.۱ of the airfoil chord from the fixed leading edge, and that of the blowing jet was ۰.۵, ۰.۷, and ۰.۹ of the airfoil chord from the leading edge. When the blowing location is at ۰.۵ of the airfoil chord, better results are observed than I n; other locations. An increase in suction jet velocity increases the lift-drag ratio between ۲۲% and ۵۵%. Also, increasing the blowing jet velocity increases this ratio between ۴۳% and ۵۵%. Horizontal blowing has the most negligible effect on improving aerodynamic characteristics. Based on the results, at the angle of attack of ۱۶°, blowing is most effective in the flow control at  with an approximate velocity of half the free stream velocity. In this condition, vertical suction has the best effect , and the lift-drag  ratio will increase by ۷۶%.