Air intake for turbojet aircraft engine

Claim 1

An air intake for a turbojet aircraft engine, comprising a duct extending lengthwise rearwardly to the engine inlet from a forwardly opening mouth, said duct having wall portions defining opposite interior surfaces that extend substantially parallel to the longitudinal axis of the aircraft so that when said axis of the aircraft is inclined to the direction of motion of the aircraft, one of said surfaces is a lee surface and the other a weather surface with respect to the stream of air entering said duct, said duct being characterized by: a slot through the wall portion that defines said one surface, said slot being 1. near the mouth of the duct, 2. elongated lengthwise of the duct, 3. defined at its rear by a surface portion which extends generally obliquely rearwardly and radially inwardly relative to the duct and is convexly curved to merge with said one surface, and 4. oriented to direct air along an interior surface of the duct that extends between said weather and said lee surfaces, in a direction obliquely rearwardly and generally from said lee surface to said weather surface, so that the slot counteracts the tendency for a transverse secondary flow to develop in the boundary layer of said surface between the weather and lee surfaces and overcomes the tendency for the boundary layer along said lee surface to have a lower velocity and stagnation pressure than that along the weather surface, thus insuring that the stream of air entering the engine inlet will have a substantially uniform distribution of velocities and stagnation pressure circumferentially around the inlet.