GB1336724A - Gas turbine engine air intakes - Google Patents

Abstract

1336724 Gas turbine engines - air intakes DEFENCE SECRETARY OF STATE FOR 26 Oct 1971 [3 Nov 1970] 52177/70 Heading F1G A gas turbine engine comprises an air intake having throat varying flaps, contraction ratio varying flaps and auxiliary air intake flaps, the flaps being adapted for simultaneous operation by common operating means. The engine shown is a ducted fan engine comprising a fan 14 and an outer cowl 16 which defines at its upstream end an air intake 24. The intake comprises a series of contraction ratio varying flaps 30 which are pivotally mounted at 32, the contraction ratio being defined by dimension A divided by dimension B. When the flaps are pivoted inwardly to the position indicated in broken lines, the contraction ratio is increased to A/C. The intake comprises also a series of throat varying flaps 34 each of which is secured to a bell crank lever 36 pivotally mounted on fixed structure at 44. The shorter arm of the bell-crank lever is movable by an actuator through a ball screw device 38 whereby the flap 34 is movable from the position indicated in full lines to that indicated in broken lines, the flap, which bears against a contraction ratio varying flap, moving the latter from the position indicated in full lines to that indicated in broken lines simultaneously. The throat varying flap 34 is also pivotally connected by link 52 to an auxiliary air intake flap 48 which is pivotally mounted at its forward end at 56 so that as the throat-varying flap 34 moves from the full line to the broken line position, the auxiliary air intake flap pivots inwards from the full line to the broken line position so opening the auxiliary air intake whereby air can flow through the annular gap 46.