Abstract: An exhaust nozzle for a gas turbine engine comprising a duct 17(c) extending along an axis and having at a dowstream end thereof a mechanism for varying the geometry and area of the nozzle. The mechanism 28 comprises an axially translatable member 28 which has a face 29 extending in a direction transverse to the axis of the duct 17(c) against which pressurized gases flowing through the duct acts to balance out the loads on the flaps. A plurality of flaps 38,43 are spaced circumferentially around the axis of the duct. The flaps 38 are pivotally attached to the axially translatable member 28 and are provided with a cam follower 40 that co-operates with a cam 37. The cams 37 are fixed relative to the duct 17(c) and thereby defines the attitude of each flap 38 relative to the member 28. Seal plates 41 and 45 cover the gaps between adjacent flaps 38 and 43 to the seal plates 45. A plurality of struts interconnect the member 28 and the second flaps of the pivotal attachment of the flaps 43 to the flap 38.

Abstract: A vectorable nozzle 17 comprising a fixed first duct 21 a rotatable second duct 22 scarfed at its rear end and a rotatable third duct 23 scarfed at its front end. The second and third ducts 22,23 are mounted in bearings 24,26 respectively and the bearing 26 is constrained to swing bodily about trunnions 29, the axis of which lies transverse to the ducts 22,23, and a screw jack 32 is provided to rotate the bearing 26 about the trunnions 29. The second and third ducts 22,23 are provided with means to rotate them in opposite directions in synchronism with the rotation of the bearing 26 in the trunnion 29. The nozzle is provided with external fairings 46,47 to provide aerodynamic streamlining when the nozzle 17 is directed rearwards. The fairings are constrained against axial and radial displacement by rollers 48 and grooves 50 at one of their ends. The fairings 46,47 are connected to their respective ducts 22,23 by members 51 so that the fairings rotate with the ducts 22,23.

Abstract: Jet propulsion powerplant comprising a gas producer 11 having a first flow duct 12 for receiving the output of the gas producer 11. The flow duct 12 includes a nozzle 13 having a center body 16 which has an upstream part 17 and a downstream part 20. Motors 22 are provided for expanding and contracting the downstream part 20 relative to the upstream part 17. A second flow duct 33 having an inlet 30 openable to airflow and connected to the interior of said upstream part 17 is provided. An outlet 24 from the interior of the upstream part 17, is provided at the downstream end of the upstream part 17. The outlet 24 opens into the interior of the first flow duct 12 by contracting the downstream part 20 relative to the upstream part 17. By such an arrangement, infrared radiation may be suppressed when necessary by opening the inlet for air flow and controlling the upstream and downstream parts so that there can be a mixing of air with exhaust gases which reduces the mean temperature of the exhaust gases.

Abstract: An exhaust nozzle for a gas turbine engine comprising a duct 17(c) and a mechanism for varying the geometry and area of the nozzle. The mechanism includes a plurality of movable flaps 38 which in at least one position define a convergent part of the nozzle. Upstream of the flaps 38 there is provided one or more outwardly directed openings 59 in the wall of the duct 17(c) and a pair of mutually confronting doors 61 which rotate about an axis transverse to the length of the duct. The doors 61 are located relative to the duct 17(c), the openings 59 and the flaps 38, so that in a first position, the doors 61 obturate the one or more openings 59 and provide a substantially unrestricted flow path through the nozzle.

Abstract: A vectorable nozzle 17 comprising a fixed first duct 21 a rotatable second duct 22 scarfed at its rear end and a rotatable third duct 23 scarfed at its front end. The second and third ducts 22,23 are mounted in bearings 24,26 respectively and the bearing 26 is constrained to swing bodily about trunnions 29, the axis of which lies transverse to the ducts 22,23, and a screw jack 32 is provided to rotate the bearing 26 about the trunnions 29. The second and third ducts 22,23 are provided with means to rotate them in opposite directions in syncronism with the rotation of the bearing 26 in the trunnion 29.

Abstract: An exhaust nozzle for a gas turbine aero-engine comprising a duct 17(c), a plurality of movable flaps 38,43 for varying the geometry of the nozzle, one or more forwardly and outwardly directed openings 59 located upstream of the flaps 38,43 and a pair of mutually confronting doors 61 each of which is mounted for rotation about an axis extending transverse to the length of the duct 17(c). The doors 61 are located relative to the duct 17(c) and the openings 59 so that, in a first position, they obturate the openings 59 and mutually confronting surfaces 67 of the doors define therebetween part of the gas flow path through the nozzle, and the doors 61 are movable to a second position, upstream of the first position, where they uncover the openings 59, define, at their upstream ends 68, a reduced area throat for the gas flow path through the nozzle. In the second position the doors 61 also define a divergent part of the gas flow path immediately downstream of the said throat.

Abstract: An exhaust nozzle for a gas turbine aero-engine comprising a duct 17(c), a plurality of movable flaps 38,43 for varying the geometry of the nozzle, one or more forwardly and outwardly directed openings 59 located upstream of the flaps 38,43 and a pair of mutually confronting doors 61 each of which is mounted for rotation about an axis extending transverse to the length of the duct 17(c). The doors 61 are located relative to the duct 17(c) and the openings 59 so that, in a first position, they obturate the openings 59 and mutually confronting surfaces 67 of the doors define therebetween part of the gas flow path through the nozzle, and the doors 61 are movable to a second position, upstream of the first position, where they uncover the openings 59, define, at their upstream ends 68, a reduced area throat for the gas flow path through the nozzle. In the second position the doors 61 also define a divergent part of the gas flow path immediately downstream of the said throat.

Abstract: An ejector nozzle for a turbomachine comprising fixed inner and outer ducts 16,19 to the downstream ends of which is provided a mechanism for varying the geometry and area of the nozzle. A plurality of pivotal flaps 20,20a are mounted on the inner duct 16 for rotation about their pivots. An axially movable shroud 25 is provided downstream of the outer duct 19. A plurality of second flaps 23,23a are pivotally attached to the first flaps 20,20a and slide relative to the shroud 25. The second flaps 23 have openings therein and doors 30 to close the openings. Links 31 which are connected to the shroud 25 are used to open and close the doors. Rotation of the flaps 20,20a and axial movement of the shroud 25 alters the geometry of the nozzle and can be used to open air inlet openings on the downstream side of the flaps 20,20a and also open the doors 30 in the second flaps 23,23 a to provide a mixer to reduce infra-red radiation emitted by the hot gas plume from the engine.

Abstract: An ejector nozzle for a turbomachine comprising fixed inner and outer ducts 16,19 to the downstream ends of which is provided mechanism for varying the geometry and area of the nozzle. A plurality of flaps 20, 20(a) which slide in curved tracks 21 are provided to define the throat of the nozzle. An axially movable shroud 25 is provided downstream of the outer duct 19. A plurality of second flaps 23, 23(a) are pivotally attached to the downstream ends of the flaps 20, 20(a) and to the downstream end of the shroud 25. The second flaps 23, 23(a) having openings therein and doors 30 to close the openings 29. Links 31 which are connected to the shroud 25 are used to open and close the doors 30. By sliding the flaps 20, 20(a) in their tracks 21, and translating the shroud axially the geometry of the nozzle can be altered to cater for "dry", " reheat" and "ejector" modes of operation. In the "ejector" mode the shroud is moved rearwards to uncover air inlets and the links 31 push open the doors of the nozzle throat.

Abstract: A nozzle for a gas turbine aero engine comprises two spaced inner and outer ducts 16,19 with a mechanism for varying the geometry of the nozzle exit. Air inlet openings 21 are provided downstream of the ducts. The mechanism comprises two pairs of mutually confronting doors 22,23 downstream of the ducts 16,19 and two pairs of pivotal flaps 26,27 mounted downstream of the doors 22,23. The inner doors 23 are provided with a convoluted mixer chute assembly 24 and serve to define the throat of the nozzle whereas the outer doors 22 serve to close off the air inlets 21 or open them, and also form a thrust reverser. The pressures acting on flaps 26,27 cause them to readjust their attitude to form a parallel or divergent part of the nozzle.