Abstract: A load transfer arrangement is provided to act as a stabiliser for utilisation in centring rotational instabilities which may occur in rotor devices such as those within a gas turbine engine. By providing a fixed screw thread path which comprises a groove having channels and having constrictions and which define clearance crowns an acceptable eccentricity range it is possible to slow screw thread driving motion and therefore load transfer only to the positions where the rotational eccentricity enters tapers leading to the constrictions. In such circumstances an orbit thread is then progressively brought into confinement and continuous engagement with a fixed screw thread defined by crowns of channels of the fixed screw thread path defined by the continuous groove through the channels. In such circumstances wide eccentricity is allowed initially but as rotational speed reduces greater and more continuous driving motions are provided whilst avoiding excessive loading during early stage operation.

Abstract: A fan casing assembly for a gas turbine, the assembly having a fan casing for surrounding a fan, a resilient, flexible containment material around the outside of the fan casing for containing a detached fan blade that breaches the casing during a fan blade off event, and a retaining cable arrangement for resisting separation of a first and second portion of the casing as a result of the breach. The cable arrangement includes a continuous length of retaining cable extending around the fan casing on the outside of the containment material, the retaining cable being slidably or rollably secured to each of the first and second portions at a plurality of positions around the fan casing to form respective cable spans between the casing portions, there being sufficient overall slack in the cable for accommodating radial flexing of the underlying containment material upon impact of the detached fan blade.

Abstract: A method for controlling the machining of a component includes the steps of: (i) measuring predetermined dimensions of a component; (ii) comparing the measured dimensions against design data defining a required shape for the component; (iii) using the results of the comparison to define material removal that is needed to bring the component to the required shape; (iv) delivering the component to a site at or adjacent to a machining station having a material removal tool, the component being gripped by a robotic manipulator at said site; (v) using the defined material removal and the known position of the robotic manipulator at the machining station to determine movements of the material removal tool that will produce the required shape for the component; and (vi) performing a machining operation on the component at the machining station using the determined movements while maintaining the grip on the component by the robotic manipulator.

Abstract: A combustion chamber includes at least one annular wall. The annular wall includes a plurality of segments and each segment has a first portion, a second portion and a third portion. The first portion of each segment extends circumferentially, the third portion of each segment extends circumferentially and the second portion of each segment extends radially to connect the first portion and third portion of the segment. The segments are arranged such that the first portion of each segment overlaps the third portion of an adjacent segment and the first portion of each segment is bolted to the third portion of the adjacent segment. The segments are cast and define a double wall combustion chamber and enable easier construction of the combustion chamber and replacement of damaged segments.

Abstract: A fuel injector head for a gas turbine engine comprising: a pilot injector having a central axis, the pilot injector being arranged to direct fuel and air to a pilot combustion zone, a main injector located radially outwardly of the pilot injector and being arranged to direct fuel and air to a main combustion zone, a splitter separating the pilot injector from the main injector and comprising a body, the body defining an axis, an annular surface and a downstream edge wherein the annular surface has a circumferentially varied axial length so that interaction between the pilot combustion zone and the main combustion zone initiates from least two different axial positions.

Abstract: A sealing arrangement, for example for providing an intershaft seal between shafts of a gas turbine engine, includes an air-riding sealing ring disposed between runners. A buffer fluid, such as air, is conveyed to a buffer cavity through a passage in the sealing ring. The buffer air provides a positive pressure drop along fluid-riding gaps, preventing leakage across the sealing arrangement. The sealing ring may be a split carbon ring, and measures may be provided to minimise leakage of buffer air at the split.

Abstract: A tip clearance control device adapted to control the clearance of a rotating aerofoil structure with a surrounding casing portion, and a method of controlling the tip clearance of a rotating aerofoil structure with a surrounding casing portion. The device includes a member operatively connected to the casing portion; the member having at least a first configuration in which the casing portion is at a first radial position and a second configuration in which the casing portion is at a second radial position, wherein the configuration of the member is controlled by magnetic flux in a magnetic circuit which includes at least one ferromagnetic element including ferromagnetic material, where the configuration of the member is responsive to the temperature of the ferromagnetic element.

Abstract: A gas turbine engine rotor blade has an airfoil portion containing one or more internal conduits. Each conduit extends to an end of the airfoil portion. The blade has a shroud at the end of the airfoil portion for sealing the blade to a facing stationary engine portion. There is a fillet portion which joins the end to the shroud. The fillet portion eases the transition from the outer surface of the airfoil portion to the outer surface of the shroud and has a cavity which extends from each conduit and expands laterally relative thereto. The area of the cavity on a cross-section through the fillet portion perpendicular to the radial direction of the engine and at an expanding part of the cavity is greater than the area of the conduit, or the combined areas of the conduits, on a parallel cross-section at the end of the airfoil portion.

Abstract: A fuel injector head for a gas turbine engine the head comprising a pilot injector and a main injector located radially outwardly of the pilot injector. A concentric separates the pilot injector from the main injector and bounding a duct through which in use a fuel injected by the pilot injector flows. The splitter is hollow to improve cooling and has a radially inner surface which defines a first portion which tapers radially inwardly to a throat and a second portion which tapers radially outwardly from the throat with the angle of the radially outwards taper being such that a flow of air in use over the radially inner surface remains attached over the length of the surface.

Abstract: A method of joining plates of material to form a predetermined structure, the method comprising: assembling a first plate (40) of a material comprising at least one recess (100) against a second plate (80) of material such that the at least one recess (100) of the first plate (40) is in an exterior surface of the first plate (40) on a side of the first plate opposite to the side which faces the second plate (80); bonding a portion (120) of the first and second plates (40, 80) to one another; superplastically forming the bonded plates, wherein the superplastic forming causes the material of the second plate (80) which is opposite to the at least one recess (100) of the first plate (40) to be driven towards the recess (100), and wherein the unbonded portion of the second plate (80) is deflected away from the plate to form the predetermined structure.

Abstract: Blade assemblies are provided in a number of forms. These blade assemblies may have blades secured to disks (blisk), rings (bling) and drums (blum). The blades and/or the rotor elements formed by these rings, drums or disks can fragment and it is necessary to contain such fragments within a casing. Impact energy has a significant effect upon the necessary thickness of the casing to ensure containment. By providing blades as well as rotor elements which incorporate discontinuities which provide flexing under impact, energy is absorbed prior to further fragmentation upon impact engagement with a casing surface; flexing is about the discontinuity. In such circumstances casings may be thinner and therefore significant weight savings achieved with regard to aircraft incorporating gas turbine engines having blade assemblies with discontinuities.

Abstract: The invention relates to a gas discharge tube (30) of a type that may be used for example in gas turbine engine (10) ignition systems. The gas discharge tube (30) has an envelope (42) containing a gas therein and the envelope has a pair of spaced electrodes (38, 40) for application of an electric potential difference across the gas. An electromagnetic radiation source (44), such as a deep UV light source, is arranged to emit photons (50) into the envelope (42) so as to initiate ionisation of the gas, thereby reducing the potential difference required to cause electrical conductance between the electrodes. The electromagnetic radiation source, which may comprise light emitting diodes, may be selectively controlled.

Abstract: A method of imparting deep compressive residual stress to an aerofoil, the method involves determining a stress map for the aerofoil for stress generated by Foreign Object (FOD) impact, a stress map for the aerofoil of high cycle fatigue, a stress map for the aerofoil of low cycle fatigue and determining a combined stress map by combining the stress map of FOD impact, the stress map of high cycle fatigue and the stress map of low cycle fatigue. A zone is then defined on the aerofoil from the combined stress map for receiving the deep residual compressive stress, and compressive residual stress imparted to the defined zone.

Abstract: A ducted fan gas turbine assembly has a propulsive fan driven by a core engine. The turbine assembly has an annular bypass duct which receives an airflow from the fan and is bounded on the radially inward side by the core engine and on the radially outward side by an engine nacelle. The turbine assembly has a thrust reverser assembly having a vane arrangement including a first set of turning vanes for channelling airflow from the duct in a rearward direction, a second set of turning vanes for channelling airflow from the bypass duct in a forward direction. The thrust reverser assembly includes a plurality of blocker doors which are deployable to block the bypass duct. The nacelle has stationary and movable cowl portions that cooperate with the thrust reverser assembly to provide several operational configurations.

Abstract: A composite aerofoil, the aerofoil having a leading edge, a trailing edge a pressure side and a suction side and comprising an outer erosion protection layer along one or both of the pressure side or suction side, a structural core having a plurality of resin impregnated plies of unidirectional fibres, and between the outer erosion protection layer and the structural core a woven composite impregnated with a resin having a modulus of elasticity greater than that of the resin impregnating the plies in the structural core.

Abstract: A master component is provided for use in checking for any variation in the performance of a gas turbine test facility. The master component replaces a standard component, which is typically a turbine blade, vane or segment in the test facility. The master component is attached to the test facility in the same manner as the standard component. The flow rate through the master component is substantially the same as the flow rate through the standard component for a given inlet and outlet temperature and pressure. The flow through the master component is simpler than the flow through the standard component. This means that the flow through the master component is less likely to vary over time. As such, the master component is more suitable for use in checking for any variation in the performance of a test facility.

Abstract: A sealing plate for sealing a gap between two primary sealing plates is provided. The sealing plate has a sealing portion and a connector portion, wherein the sealing portion has a width which is greater than a width of the connector portion. An apparatus for sealing a gap between two structural components of a turbine, the apparatus including a plurality of primary sealing components, and at least one sealing plate is also provided, as is a turbine having a plurality of structural components with a gap between said structural components, wherein the gap is sealed by a plurality of sealing components, the sealing components comprising a plurality of primary sealing components and at least one sealing plate.

Abstract: A cooled component for a gas turbine engine, for example a turbine rotor blade, is provided. The component has an internal cooling flow passage. Cooling air is passed through the internal cooling flow passage to remove heat from the component and thereby reduce its temperature. The cooling air is bled from the internal cooling passage after it has passed through a portion of the passage into an internal bleed flow passage. This bled air is then used in a seal. Thus, some of the cooling air that enters the internal cooling flow passage is used both to cool the component and to form a seal, for example with another component.

Abstract: A method of inhibiting ice accretion within a turbine engine 4, 6, comprising the steps: (a) operating the turbine engine 4, 6 at a predetermined engine speed; and (b) driving the compressor 8, 10 of the turbine engine 4, 6 at an elevated speed which is greater than the nominal speed of the compressor 8, 10 at the predetermined engine speed so as to inhibit ice accretion within the compressor 8, 10.

Abstract: A method of bonding a first component (10) comprising a titanium-containing alloy to a second metal component (12), wherein a coating layer (14,16) is applied to each of the first and second components in the region to be bonded. The coating layers (14,16) comprise a precious metal. An intermediate metallic layer (18) is interposed between the coating layer (14) of the first component and the coating layer (16) of the second component. The respective coating layers are held in contact with the intermediate layer (18) and the coating layers and the intermediate layer are heated to initiate melting of at least one of said layers so as to form a bond between the first and second components by brazing.