Patent EA-000814-B1 (EA)
Title: Aircraft wing assembly
Inventor: COLLETT EDWARD
IPC: B64C21/06
Filed: 1998-04-20
Abstract: 1. An aircraft wing assembly including a main wing portion and a leading edge high lift portion movable between a retracted position in which it generally merges with the main wing portion and a deployed position forwardly thereof, wherein at least a substantial part of the exposed upper surface of said high lift portion is air permeable or perforated and in flow communication with a suction passage associated with said high lift portion, whereby in flight, suction may be applied to said suction passage to at least reduce the chordwise extent of the turbulent boundary layer over at least one of the upper and lower wing surfaces. 2. An aircraft wing assembly according to claim 1, including means for controlling the degree of suction at selected points or regions over the exposed surface. 3. An aircraft wing assembly according to claim 2, wherein said means for controlling comprises a plurality of chambers extending within said leading edge slat portion and in flow communication with the air permeable or perforated part of the exposed surface, and said flow passage. 4. An aircraft wing assembly according to claim 3, wherein said means for controlling comprises one or more orifice means or restricted passage means associated with one or more of said chambers, for controlling the flow to or from said chamber. 5. An aircraft wing assembly according to claim 3 or claim 4, wherein each of said chambers is elongate and extends generally spanwise. 6. An aircraft wing assembly according to one of the preceding claims, wherein said leading edge high lift portion comprises a slat which includes a trailing edge region which lies in contact with or closely adjacent the main wing portion when said slat is in its retracted position, said assembly further including passage or perforation means for drawing in air or applying suction in the region of the interface between the trailing edge region of said slat and the main wing portion. 7. An aircraft wing assembly according to claim 6, wherein said passage or perforation means includes orifice means in the surface of the slat portion which faces the wing portion, said orifice means being in flow communication with said flow passage. 8. An aircraft wing assembly according to claim 7, wherein said passage or perforation means comprises a plurality of generally spanwise spaced channels in the trailing edge region of said slat portion which co-operate with the adjacent surface of the main wing portion when the slat region is in the retracted position, to define a plurality of suction ports at said interface. 9. An aircraft wing assembly according to claim 6 or 7 or 8, wherein seal means extending generally spanwise on the rearward facing surface of the slat portion to provide a seal when the slat portion is in the retracted position. 10. An aircraft wing assembly according to any preceding claim, including one or more suction pump means for applying suction to said suction passage. 11. An aircraft wing assembly according to claim 10, wherein a suction pump means is located in said main wing portion and is in flow communication with said high lift portion via extendable suction duct means extending between main wing portion and the high lift portion . 12. An aircraft wing assembly according to any of the preceding claims, include one or more further high lift  portions, the said high lift portions being arranged spanwise with respect to each other, and each high lift portion including a said suction pasage in flow communication with a suction passage of at leastone other said high lift portion. 13. An aircraft wing assembly according to claim 12, wherein said flow communication  with a suction passage of at least one ohtersaid high lift portion takes place via a further seal acting between adjacent high lift portions. 14. An aircraft incorporating a wing assembly according to any of the preceding claims. 15. A leading edge high lift device for use with a main wing portion for being moved between a retracted and a deployed position, wherein at least substantial part of the upper surface of the high lift device is air permeable or perforated and in flow communication with a suction passage of said high lift device whereby, in flight, suction may be applied to cause a negative pressure difference to at least reduce the chordwise extent of the turbulent boundary layer over at least one of the upper and lower wing surfaces. 16. A leading edge high lift device according to claim 15, including a series of generally spanwise spaced channels in a trailing edge region thereof. 17. A method of reducing the drag associated with an aircraft wing having a leading edge high lift device, which method is characterized by providing a substantial part of the exposed upper surface of the high lift device with an air permeable or perforated surface and applying suction through said surface to at least reduce the chordwise extent of the turbulent boundary layer on at least one of the upper and lower wing surfaces.