Passive flow control around the airfoil with slot

In this thesis, numerical analysis was performed to control of flow over NACA 0018 airfoil with slot at variant angles of attack. The Reynolds number was set to Re=3x10^5. Inlet of slot was posiniated on the pressure side of airfoil at chordwise location of x/c=5% while outlet of slot was located on the suction side of airfoil at three different chordwise location. Numerical analyzes were carried out using two different turbulence models, K-ω SST and K-ε RNG. Obtained results from the numerical analyzes were evaluated in terms of effect of the slot on flow structure and aerodynamic forces. It was observed that the location of slot remarkably affect flow over airfoil and delays stall angle. The model 40 suppress the formation of recirculation region formed over the airfoil. Furthermore, it was observed that while the stall angle of base airfoil is α=16°, it was delayed up to α=20° for Model 40. Also, it was observed that the lift coefficient was increased by 154% for Model 40 at α=19°. On the other hand, it was observed that Model 20 significantly effective on the flow control in comparison with the base airfoil at angles of attack of α ≥13°, while it has insignificant effect at low angles of attack. Similar observation was also obtained for Model 60 at low angles of attack. According to obtained results from both turbulence models, the most efficient model was determined as Model 40 in order to control flow around the airfoil especially for post stall angles.