Abstract
A flow around an airfoil controlled by using blowing and suction is studied by means of direct numerical simulation. A uniform suction is applied near the leading edge in order to delay the transition, while a uniform blowing is applied near the trailing edge to reduce the friction drag of a fully developed wall-turbulence. As a result, both the friction drag and the pressure drag are reduced. The reduction of the pressure drag reduction is attributed to an increase of the pressure on the rear part of the airfoil, while the reduction of the friction drag is due to the modification of the velocity profile on the controlled surface.
