Abstract: This invention provides a valve for diverting fluid flow in a tandem fan type engine. The valve comprises an axially displaceable sleeve 38 which is provided with two circumferentially extending sealing lands 40, 42 which in operation cooperate with two locating surfaces 50, 52 provided on the duct 22 between the first and second compressors 20, 24 of said engine to seal an outlet opening 36. The free unsprung length between the sealing lands 40, 42 is greater than the length between the locating surfaces 50, 52. Gas pressure is used to compress a contractable portion 54 in said sleeve and hence ensure sealing takes place between both pairs of locating surfaces and sealing lands. This apparatus ensures centralisation of the upstream and downstream ends of the sleeve 38 is independently obtainable and accommodates thermal expansion differentials between the sleeve 38 and the duct 22.

Abstract: A fluid flow diverter system for use with twin engine vertical take-off aircraft. The diverter sysstem is employed to direct a portion of, or all, the working fluid from the first axial flow compressor (14) of either a by-pass engine, a twin fan engine or a variable cycle engine to either a pair of vectorable front nozzles (36) or to a by-pass duct (34). In the event of one engine failing in flight, an attempt at balancing the remaining thrust for vertical landing is made by ducting all the air normally existing from the operative engine's front nozzle (36) across to the inoperative engine's front nozzle (36).

Abstract: A jet pipe for jet propulsion in aircraft has in flow-series a first or fixed duct 13, a second duct 14 and a third duct 15. The second duct 14 is supported on the first duct 13 for rotation about a common axis 13A, 14A of these two ducts. The third duct 15 is supported on the second duct 14 for rotation about an axis 19A having an angle oblique the axis 14A of the second duct. A ring 30 is supported on the second duct 14 for rotation about the axis 14A thereof. A bracket 31 mounted on the ring 30 has a guide and slide connection 32,33 with the third duct 15. A single drive shaft 24, mounted on the fixed duct 13, is connected to rotate the second duct 14 and the ring 30 in opposite directions. The guide and slide connection effects a corresponding rotation of the duct 15 about the axis 19A. The resulting relative rotation of the ducts 14,15 results in the duct 15 moving so that the axis 15A thereof moves through an angle .beta. while remaining in a given plane 11A, 11B.

Abstract: One problem associated with aircraft using variable cycle engines is how to provide an air intake which is sufficiently large to be able to supply air to both the first and second compressors of the engine during the parallel flow mode and sufficiently small to minimize aerodynamic drag when the engines are operated in the tandem flow mode during supersonic forward flight. This invention overcomes this problem by providing an air intake which combines a blocker door covering a second portion of the duct which communicates with the second compressor and a means of varying the inlet area of the duct such that the area is maximized when the engines are required to operate in the parallel flow mode and minimized during series flow operation.

Abstract: One problem associated with aircraft using variable cycle engines is how to provide an air intake which is sufficiently large to be able to supply air to both the first and second compressors of the engine during the parallel flow mode and sufficiently small to minimize aerodynamic drag when the engines are operated in the tandom flow mode during supersonic forward flight. This invention overcomes this problem by providing an air intake which combines a blocker door covering a second portion of the duct which communicates with the second compressor and a means of varying the inlet area of the duct such that the area is maximize when the engines are required to operate in the parallel flow mode and minimized during series flow operation.

Abstract: A vectorable nozzle (17) comprises a fixed first duct (21), a rotatable second duct (22) scarfed at its downstream end, and a rotatable third duct (23) scarfed at its upstream end. The second and third ducts (22, 23) are mounted in bearings (24,26), respectively, and an epicyclic gear train (30) is provided to rotate them in opposite directions while maintaining the direction of gas efflux issuing from the nozzle (17) in a single plane.

Abstract: Jet propulsion nozzle comprises a pair of mutually confronting side walls 11, a pair of mutually confronting first panels 14 extending transversely between the walls and being supported thereon for pivotal movement about a first axis 18. A pair of mutually confronting second panels 20 situated downstream of the first panels are pivotally supported on the respective first panels by pivots 21. Actuators 19,24 are adapted to pivot the panels 14,20 so that the panels can be moved between a convergent position (as shown) and a convergent-divergent position. Further, the second panels can be pivoted into a position in which they divert the flow obliquely away from the normal flow axis 15 of the nozzle, and the first panels can be pivoted into a position in which they reverse the flow through openings 34 normally closed by these panels.

Abstract: Ducted fan propulsion unit for aircraft has a main duct 3 containing a reversible pitch fan 1 rearward of which is provided a flow splitter 13 dividing the main duct into radially outer and inner branch ducts 3A, 3B. A radial passage 15 in the splitter connects the branch ducts and divides the splitter into front and rear parts 13A, 13B. The part of the inner branch duct forward of the radial passage contains an array of stator vanes 12B and has outer and inner wall surfaces 3B1,3B2 both of progressively reducing diameter to urge the flow through that branch duct toward the inlet of a compressor 8 of yet smaller diameter. Stator vanes 12A in the outer branch duct are arranged forward of the radial passage. The arrangement favors a relatively low axial length of the powerplant.

Abstract: A ducted fan propulsion plant has a reversible-pitch fan driven by a core gas turbine engine and housed in a duct which terminates at its downstream end in an outlet nozzle defined between two semi-cylindrical shells. The shells are mounted for movement hydraulically both axially and angularly to define an increased effective nozzle area for take-off. Upon further rearward axial displacement the shells adopt a reverse-thrust position to define air inlets to the fan when the fan blade pitch is reversed.