Active Flow Control System for Simple-hinged Flaps

About this technology

Overview

Conventional high-lift systems allow transport aircraft to safely operate at low speeds for landing and takeoff. These high-lift devices, such as Fowler flaps, are complex, heavy, and have high part counts. Fowler flap mechanisms also protrude externally under the wings, requiring external fairings, which increase cruise drag. Simple-hinged flaps are less complex, and an ideal choice for low-drag cruise efficiency. However, simple-hinged flaps require high flap deflections to achieve lift comparable to Fowler flaps. These flap deflections cause severe adverse pressure gradients, which generate flow separation that is difficult to control. In response to these challenges, NASA developed the High Efficiency Low Power (HELP) active flow control (AFC) system. This simple, elegant invention can control flow separation resulting from the high flap deflections required by simple-hinged flap systems – making such flaps a viable option for aircraft designers. Aircraft with simple-hinged flap systems will achieve reduced cruise drag, thereby increased fuel efficiency.