Experimental Study of Flow Separation Control on an Airfoil by Suction and Injection

Abstract

In this research a new concept of flow separation control mechanism has been introduced to improve the aerodynamic characteristics of an airfoil. Control of flow separation over an airfoil which experiences a laminar separation bubble for a low Reynolds number is experimentally simulated under the effects of suction and injection. The suction and injection control mechanism appears to be suppression of the separation bubble and reduction of the upper surface pressure to increase the lift and decrease the drag. To perform the experiment of NACA 2415 airfoil profile has been chosen to make wing model. The wing model with control mechanism has been tested in a sub-sonic wind tunnel. The experiments are performed with different angle of aUack and different suction-injection frequency. The experimental results show that the flow separation control is possible by the proposed mechanism and benefits can be achieved by suction and injection. The wing performance is significantly improved due to control of flow separation by suction and injection. It has also been found that the lift increases about 14% and drag reduces about 23% at the angle of attack 8 degree.