Flow control (fluid)

Passive techniques include turbulators or roughness elements geometric shaping, the use of vortex generators, and the placement of longitudinal grooves or riblets on airfoil surfaces.

[1] Active flow control includes steady or unsteady suction or blowing,[2] the use of synthetic jets, valves and plasma actuators.

Airplane wing performance has a substantial effect on not only runway length, approach speed, climb rate, cargo capacity, and operation range but also noise and emissions.

Techniques developed to manipulate the boundary layer, either to increase lift or decrease drag, and separation delay come under the general heading of flow control.

It initially involved testing a small-scale plane that uses compressed air bursts instead of external moving parts such as flaps.