Air intake control for an adjustable air inlet, particularly two- dimensional oblique shock diffuser for gas turbine jet engines for the propulsion of high performance aircraft

摘要

A variable air inlet includes an air intake duct with upper ramps, an air inlet bottom spaced below the ramp and a movable air scoop lip pivotally secured to the end of the air inlet bottom closer to the opening into the air intake duct. The air scoop lip is pivotally displaceable through two angular operating ranges, a wider one in the subsonic/transonic range and a narrower one in the upper supersonic range. Various control members including computers are used to control the position of the lower air scoop lip. The movement in the subsonic/transonic range is effected in response to the flight machnumber and the aircarft angle of attack based on a given control law. The control in the supersonic range is established in response to a variable demand pressure ratio between the static pressure above the upper ramps and the free stream total pressure, with the variable demand pressure ratio being a function of the actual air scoop lip position.