Back to results
US 4,575,030 AGranted
Laminar flow control airfoil
AssigneeThe Boeing Company
InventorLouis B. Gratzer
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeThe Boeing Company
InventorLouis B. Gratzer
Estimating the term…
A laminar flow control aircraft wing combines suction surfaces and slots in its leading and trailing edge regions, with natural laminar flow over its main box region to achieve laminar boundary layer flow over a majority of the wing surface area. The wing includes a leading edge flap that is used to protect the leading edge region of the wing from insect accumulation and surface erosion caused by the impact of dirt, rain, or other airborne materials when the leading edge flap is deployed in a low-speed position. At high aircraft speeds, the leading edge flap is stored in the surface of the leading edge region of the wing and forms part of the suction system for that area of the wing. The wing also includes a flexible trailing edge suction surface spoiler system that allows the spoilers to bend downwardly when the trailing edge flap is deployed into a low-speed position.
A laminar flow control airfoil having a leading edge and a trailing edge, comprising:
A jet aircraft laminar flow control airfoil having leading and trailing edge regions and an intermediate main box region joined thereto and contoured complementally thereto so as to form an efficient composite airfoil, said leading and trailing edge regions each having upper and lower skin surface panels that are porous, said leading edge region including a leading edge flap deployable during low-speed flight from a stored cruise position to extend at a downward and forward incline at a position forward of the leading edge of the airfoil, thereby to deflect dirt and insects over the airfoil while augmenting wing lift, said leading edge region including suction slots that are formed adjacent leading and trailing edges of said leading edge flap when said flap is in its stored cruise position, said airfoil including means internal thereto for applying suction to said skin surface panels for removing boundary layer air flowing over said skin surface panels at flight speeds including cruise speed, thereby to maintain laminar flow over said skin surface panels by offsetting the natural tendency toward turbulent flow along said skin surface panels at such speeds, said main box region having top and bottom airfoil surfaces comprising the major surface area of the airfoil and being contoured to maintain favorable pressure gradients along the same that produce laminar flow inherently and substantially without aid of suction applied through the surfaces thereto to remove boundary layer air.
Dependencies are inferred from the claim text.