Abstract: A resin transfer moulding process for an article incorporating a protective insert of polymer material such as polyether ether ketone (PEEK). A piece of PEEK material is cut and thermoformed to the required shape and then placed in position in a mould. A bead of elastomer material is formed around the edge of the insert to seal it against an internal wall of the mould in order to prevent resin tracking between the mould and insert faces during subsequent injection into the mould.

Abstract: A squeeze-film damper arrangement comprising: concentric inner and outer components defining an annular gap there between for accommodating radial motion of the inner component within the outer component; and a fluid filling the annular gap around the outside of the inner component for damping said radial motion of the inner component, the fluid being axially contained between spaced-apart, radially-compliant first and second face-seals provided between the inner and outer components; wherein the first face-seal is provided between the opposing faces of a first pair of radially overlapping circumferential sealing elements associated with the inner and outer components respectively, a first one of the circumferential sealing elements in said pair being mounted for axial movement relative to the associated inner or outer component and being axially biased against the second of said circumferential sealing elements in said pair to form the first face-seal.

Abstract: A combustion device, such as an afterburner 4 for a gas turbine engine, comprises primary and secondary fuel delivery means 12, 20. Pressure fluctuations in the afterburner 4 are damped by reducing the supply of fuel through the primary fuel delivery means 12 during pressure peaks. This is achieved by means of a spill valve 18, controlled by a controller 22 in response to pressure in the afterburner 4 as sensed by a transducer 24. The spill valve 18 diverts a proportion of the fuel to the secondary fuel delivery means 20. The secondary fuel delivery means 20 is positioned upstream of the primary fuel delivery means 12 by a distance X, such that the secondary fuel delivery means serves to supply additional fuel to the combustion zone 26 during pressure troughs.

Abstract: A stage of fan aerofoils (10) lies within a fan cowl (12). The fan duct (16) is defined in part by a hard casing (14) that in turn surrounds aerofoils (10). Hard casing (14) includes wedge members (26) that fill the annular gap between ring (14) and an outer ring (20). In the event of an aerofoil (10) breaking off, the hard ring (14) and wedges (26) absorb sufficient of the kinetic energy expended by the broken aerofoil (10), as to prevent it passing through outer ring (20) on to the fan cowl (12).

Abstract: A particle damper is formed using a solid freeform manufacturing technique. A filler provides support for the closing wall of the cavity as it is formed. Apertures allow at least a portion of the filler to be removed. A particle fill of between 90 and 95% is achieved either by removing sufficient filler to reach this fill or removing excess filler and re-filling with damping particles.

Abstract: A heat exchanger (10) comprises a first sheet (12), a second sheet (14) and an additional sheet (30). The first and second sheets (12, 14) are wound around an axis (X), each sheet (12, 14) has hot and cold edges at the hot and cold ends (16, 18) respectively of the heat exchanger (10). The hot and cold edges of the first sheet (12) are joined to the hot and cold edges of the second sheet (14). The end (12A) of the first sheet (12) is joined to the second sheet (30) by an axially extending join (28) at a position spaced from the end (14A) of the second sheet (14). The end (30A) of the additional sheet (30) is joined to the end (14A) of the second sheet (14) by an axially extending join (28). The additional sheet (30) is thicker and wider than the first and second sheets (12, 14) such that at least one of the hot and cold edges (30C, 30D) of the additional sheet (30) extend beyond the hot and cold edges of the first and second sheets (12, 14).

Abstract: A blade for a gas turbine engine comprises an aerofoil having a root portion, a tip portion located radially outwardly of the root portion, and leading and trailing edges extending between the root portion and the tip portion. A shroud extends transversely from the tip portion of the aerofoil and the aerofoil defines interior cooling passages which extend between the root portion and the tip portion. The aerofoil includes a wall member adjacent the trailing edge and a support structure extending from the wall member to the shroud to support the shroud. The support structure permits a flow of cooling air from a cooling passage to the trailing edge at a region proximate the tip portion of the aerofoil. Optionally, the aerofoil also includes a flow disrupting arrangement.

Abstract: A lubrication and scavenge system for a gas turbine, capable continued operation in nose-down or nose-up orientations, has a number of oil drainage passages to return oil to one or more collection chambers adjacent a rolling element bearing. A rotary impellor in the chamber forces the oil into a scavenge off-take passageway in the chamber wall leading to a scavenge pump. However, in some orientations windage effects in the chamber can return the oil to the drainage passage rather than permitting the impellor to centrifuge it into the off-take passageway. As a result oil starvation may occur. To avoid this and improve scavenging a shield is located between the drainage path and the off-take passageway adjacent to a face of the impellor. The shield may comprise an additional member, but preferably is formed integrally with a bearing race so as to ease assembly.

Abstract: An exhaust nozzle for a gas turbine engine includes a nozzle casing having top and bottom walls and side walls. A liner is provided within the nozzle casing to define a cooling passage. The top and bottom walls each include mutually inclined planar wall portions which meet at respective creases. The creases increase the rigidity of the top and bottom walls. In addition, the inclined wall portions cause the cooling passage to taper in the direction outwardly from the creases, so assisting in the cooling air distribution over the liner.

Abstract: A disc arrangement for a gas turbine engine, the disc arrangement including a rotational axis, a disc, a coverplate, and a retainer to retain association between the disc and the coverplate by interference. The retainer is displaceable in a recess of the disc or the coverplate to allow release of the interference. The recess presents the retainer at an inclined angle to the rotational axis for the disc and/or the coverplate.

Abstract: An article such as a fan blade of a turbofan engine comprises a core made up of components at least some of which comprise packs of rods embedded in a resin matrix material. The rods extend in the span-wise direction of the blade to resist centrifugal forces imposed on the blade during operation. The core is encased in a skin-formed from preforms which may comprise fabric reinforcements.

Abstract: A method for determining total pressure distribution across a fan entry plane of a fan situated within a fan casing provided with struts which are positioned upstream of the fan, with respect to the normal air flow direction through the fan.

Abstract: A fastener 10 for fastening a welding nozzle to a gas output device, the fastener 10 comprising: a first clamping member 12 and a second clamping member 14, moveable between an open configuration and a closed configuration, and which define an aperture 24 for receiving the welding nozzle, the first clamping member 12 including: a member 34 for resiliently engaging the welding nozzle, wherein the member 34 is arranged to be progressively deformed by the welding nozzle as the first clamping member 12 and second clamping member 14 move from the open configuration toward the closed configuration, and is arranged such that the degree of deformation of the member 34 by the welding nozzle achieved when the first and second clamping members 12, 14 reach the closed configuration is equal to, or less than, the maximum resilient deformation of the member 34.

Abstract: An acoustic assembly for a fan casing of a turbofan engine is made up from acoustic liner panel components which each comprise a body and a backing sheet. The body is an integral injection moulding comprising an acoustic structure, a perforated sheet and fastening portions. Adjacent panel components engage each other at non-linear circumferential edges which comprise lugs on one of the components which are received in recesses of the other component. The lugs are defined by following cell walls over a convoluted path along the circumferential edge.

Abstract: An aerofoil (35) for example a fan blade (26) comprises a leading edge (36), a trailing edge (38), a concave pressure surface extending (40) from the leading edge (36) to the trailing edge (38) and a convex suction surface (42) extending from the leading edge (36) to the trailing edge (38). The aerofoil (35) comprises a metal foam (50) arranged within a cavity defined by metal workpieces (52, 54). The metal foam (50) of the aerofoil (26) ideally has a density of less than 1g/cm3, is cheaper to manufacture and has improved fatigue behaviour and impact capability.

Abstract: A health monitoring apparatus for a mechanical system includes: a microphone arranged to receive sound from the system; and a processor adapted to process the output of the microphone. The mechanical system may be a gas turbine engine. Further, the engine may have a plurality of bleed valves, each of the bleed valves being configured such that, when open, it produces a sound which is distinguishable from the sounds produced by the other bleed valves, and the microphone being arranged to detect the sound from the bleed valves.

Abstract: Reduction in weight is an important factor with respect to turbine engines used in aircraft. Blades (20) used in such turbine engines may fragment such that it is necessary that the containment casing (42) can resist such fragmentation. Root portions of blades are generally less deformable and therefore require conventionally more robust containment casings. Use of super plastically formed blades allows provision of slots (4, 14, 24, 46) in the root portion which facilitate fragmentation and deformation by the root portion under impact reducing the necessity for greater reinforcement of the containment casing. The slots (4, 14, 24, 24, 46) are created in a membrane utilised for web reinforcement of the blade rather than through intrusive drilling and cutting processes which may introduce machining stresses into their creation and potential tool loss within the high value blade.

Abstract: A lower cost combustor is formed from a series of sheets of metal that are secured by mechanical fasteners. An increase in diameter of the combustor is achieved through the provision of securing rings to which the sheets of metal are secured.

Abstract: An earthing arrangement for a DC electrical system (10), the electrical system (10) comprises a plurality of earthing points (24A, 24B, 24C) and each earthing point (24A, 24B, 24C) is directly and permanently connected to earth (26) by a high impedance connection (28A, 28B, 28C). Each earthing point (24A, 24B, 24C) is selectively connectable to earth (26) in electrical parallel with the high impedance connection (28A, 28B, 28C) by a solid connection (30A, 30B, 30C) and a switch (32A, 32B, 32C). In first mode of operation the switch (32A) between the earthing point (24A) and the earth (26) of only one of the plurality of earthing points (24A, 24B, 24C) is closed.

Abstract: An annulus filler is provided for mounting to a rotor disc of a gas turbine engine and for bridging the gap between two adjacent blades attached to the rotor disc. The annulus filler defines an airflow surface for air being drawn through the engine. The annulus filler has one or more primary connectors for connecting the annulus filler to the rotor disc, and for resisting, in use, centrifugal forces on the annulus filler. Each primary connector allows rotation of the annulus filler around the centre line of the engine relative to the rotor disc at that primary connector. The annulus filler also has a secondary connector for connecting the annulus filler to the rotor disc and for resisting, in use, motion of the annulus filler relative to the rotor disc in a first axial direction. The secondary connector allows rotation of the annulus filler around the centre line of the engine relative to the rotor disc at the secondary connector.