Abstract: A blade tip clearance control apparatus (10) comprises a plurality of circumferentially arranged spaced wall members (16) located adjacent the rotor path of a plurality of rotor blades (14). Each wall member (16) is mounted on a carrier (18) attached to an annular casing (22) radially outward thereof. Thermal expansion or contraction of the carrier (18) causes radial movement of the wall members (16). The wall members (16) have at least one fluid passage (20) therein. In operation a flow of fluid passing through the fluid passages (20) causes either thermal expansion or contraction of the wall member (16) to different radial positions.

Abstract: A high temperature mounting system useful, for example for ceramic composite flameholders in a gas turbine engine reheat system uses dovetail clamping. A flameholder carries a dovetail projection which is clamped against a further ceramic, intermediate member by wedge blocks on opposite sides of the dovetail. The intermediate member has raised edges with angled faces opposite the dovetail projection against which the wedge blocks bear. The assembly is clamped to a metal support or flange by clamp bolts which pass through each of the wedge blocks and the intermediate member. The included angle of the contact faces is determined by principles of DAZE geometry to keep the bolts from loosening due to differential thermal expansion. Each wedge block is clamped by single bolt and relative expansion between the bolts is absorbed by bolt bending or nut sliding.

Abstract: A fluid flow duct such as the jet pipe of an aircraft gas turbine powerplant has alternatively selectable outlets so that thrust may be directed through either an axial discharge nozzle or through vectorable lift nozzles. Side outlets in the jet pipe leads to lift nozzle on port and starboard sides of the aircraft. Nozzle selection is made by means of a composite diverter valve comprising a sleeve valve to cover the side outlets and a segmented blocker valve to close the jet pipe and deflect engine exhaust through the side outlets. The blocker valve segments are carried on the sleeve valve for simultaneous deployment. The segments are adapted to delay the opening of the side outlets as the sleeve valve translates axially. Specially extended segments co-operate with a shaped duct wall adjacent the outlets to delay their uncovering.

Abstract: A mounting arrangement for a composite material flameholder in teh reheat system of a gas turbine engine provides for a flameholder to be suspended from a flameholder bracket in the jet pipe by a means of pivotal mounting and to be restrained from movement by a leaf spring mounted trunnion attached between the bracket and the flameholder at a second mounting spaced a short distance away from the first. The resilience of the leaf spring allows movement in directions parallel to a line through the axes of the two mountings in order to accommodate differential thermal growth of the composite flameholders and their metallic supporting structure.

Abstract: A barrier for use in laser drilling. The barrier is placed in front of those surfaces that one wishes to protect from the laser beam. The barrier comprises a thixotropic medium, for example polyacrylamide suspension in water. The medium includes material which will disperse the laser light and material which will emit light when exposed to the laser light. The light emitter materials could be luminescent materials, phosphorescent materials, or fluorescent materials.

Abstract: A connector for conveying hydraulic pressure from a relatively fixed source to a relatively moveable hydraulically actuable arrangement is described. The connector comprises a telescoping assembly of hollow members opposite ends of which have means for joining the connector to hydraulic lines. A first of the telescoping members is formed with an integral annular chamber which is swept by annular piston means carried by a second of the telescoping members interengaged with the first. Dimensions are chosen so that a change in the internal volume of the telescoping members is compensated by the volume displaced by movement of the piston in the chamber whereby the total internal volume of the system remains constant.

Abstract: A vectorable propulsion nozzle has first and second ducts 10, 16 attached to each other by gimbal attachment means 18 to allow universal swivelling of vectoring in any lateral direction. The second duct 16 comprises a supporting ring 28 which has a plurality of guide means 36 in which arcuate ribs 41 are slidably mounted. Each rib 41 is formed integrally with a master flap 38 which together with slave flaps 44 define the geometry and outlet area of the nozzle. To facilitate varying the throat area of the nozzle the flaps 38, 44 are moved bodily along the guide means by actuators. The area of the nozzle can thus be altered independently of the swivelling of the second duct 16. The supporting ring 28 also has formed therein a plurality of openings 30 for thrust reversing which are uncovered when reverser doors 32 are deployed.

Abstract: An aircraft has two vectorable front nozzles each mounted in a bearing located within the fuselage near an adjacent wing. Each nozzle is rotatable from a first position in which exhaust air is directed downwards to a second position in which the exhaust air is directed rearwards. In the first position the nozzle resides within a cavity formed in the wing root to reduce nozzle drag when the aircraft is propelled by its rear nozzle only. The front nozzles rotate out of their respective cavities to the second position when they are used for forward thrust. Additionally, the cavity is extended to form a passage through which secondary air entrained by exhaust from the front nozzle operating in the first position adds to the vertical thrust and reduces suck down effects.

Abstract: A propulsion nozzle of a gas turbine engine comprising two mutually confronting spaced fixed side walls 14, 16 and two upper and lower mutually confronting spaced movable walls 20, 22 which locate and move in trackways 18 in the side walls. The movable walls 20, 22 each comprise a plurality of pivotally interconnected members which extend transverse to the fixed walls to define a convergent part and throat of the nozzle.A flap 28 is pivotally connected at its upstream end to a downstream end of one of the movable walls 20(b) and is operable, in at least one mode of operation, to cooperate with the fixed walls to define a divergent expansion ramp downstream of the throat of nozzle. In a first mode of operation, the movable walls 20, 22 can be moved along the trackway 18 to cause the members to define a con-di nozzle facing rearwards to produce forward thrust.

Abstract: A variable flow area nozzle suitable for a gas turbine engine equipped with afterburning means comprises first and second ducts, the second duct pivotably mounted to the first and extending downstream from the first duct thereby defining a fluid flow therethrough. The first duct includes a lip which extends downstream through the second duct, the lip being of width corresponding to the internal width of the second duct thereby defining an exit orifice the flow area of which is controlled by the position of the second duct with respect to the lip. The nozzle further comprises a pressurizable chamber located on a side of the lip remote from the fluid flow path, the chamber being defined at least in part by the lip and a portion of the second duct. A vent hole in the lip is provided for admitting fluid into the chamber from fluid flow path.

Abstract: One major problem associated with the design of high-speed vertical take-off or landing aircraft is the requirement to have the front vectorable nozzles of the aircraft deployed in the airstream which passes over the fuselage of the aircraft when they are in use. The nozzles tend to act as air brakes and thus seriously effect the forward speed and flight characteristics of the aircraft. This invention attempts to solve this problem by providing a vectorable nozzle which is rotatable about one axis between a first position in which it is stowed inside a cavity within the aircraft fuselage when not required, and a second position in which it is deployed into the airstream when required.

Abstract: An ejector nozzle comprising an axially translatable member on which is mounted an axisymmetric array of first flaps 36 and hinged seal plates 39 which serve to define a variable area convergent nozzle. The first flaps have cam followers 38 that co-operate with cams 35 to determine the attitude of the first flaps 36. A plurality of second flaps 40 and second seal plates 43 are mounted on the first flaps. The upstream end of the second flaps 40 are spaced from the downstream ends of the first flaps 36 to form an air inlet. An axisymmetric array of third flaps 50 surround the first and second flaps 36,40. The third flaps 50 are pivotally connected at their downstream ends to the downstream ends of the second flaps 40, and are connected at their upstream ends to fixed structure 32,45,47 by pivotal links 49. A fixed ring 46 carrying rollers 51 surrounds the second flaps 40 at a region intermediate their upstream and downstream ends. The rollers 51 provide a fulcrum about which the second flaps 40 rock.

Abstract: A valve for selectively changing the direction of flow of working fluid through a variable cycle engine which comprises a first and second compressor 14,16 spaced along a flow duct 26. The duct 26 having air intakes 42 leading to the second compressor 16 and outlets leading to nozzles 44. The valve comprising a sleeve 30 axially movable along the duct. The sleeve 30 having openings 31 in it in which are located doors 32. Links 36 are connected to each of the doors 32 so that as the sleeve 30 is moved axially the doors 32 are pulled open to open the air inlets 42 and the outlets and simultaneously obturate the flow duct 26. In a second position of the sleeve 30 the doors 32 and the sleeve 30 close off the air inlets and outlets and open the duct to allow the first compressor to supercharge the second compressor.

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 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.