Abstract: The present invention provides a casing assembly for a gas turbine engine comprising a radially inner casing and a radially outer casing. The assembly further comprises an axial mounting arrangement for mounting the inner casing and outer casing in a fixed axial relationship. The axial mounting arrangement allows radial movement of the outer casing relative to the inner casing such that distortion of the inner casing as a result of engine carcass loads on the outer casing is obviated as the inner casing is radially isolated from the outer casing.

Abstract: A propulsion system is disclosed comprising a gas turbine engine and an acceleration schedule which determines the rate of acceleration of the gas turbine engine from an idle condition in response to a demand for increased thrust off-idle. The acceleration schedule determines the rate of acceleration in dependence upon the value of an engine parameter of the engine the value of which is substantially unaltered by variation in the magnitude of an electrical load drawn from the engine while it is operating in the idle condition.

Abstract: A thermal management system for a gas turbine engine comprises a plurality of first heat generating sub-systems arranged in operable communication with the engine, a fuel supply sub-system, a fuel circulation sub-system, and one or more combustors. The fuel supply sub-system is adapted to supply a de-oxygenated fuel to the fuel circulation sub-system, and the fuel circulation sub-system is adapted to circulate the de-oxygenated fuel to lubricate and cool each of the plurality of first heat generating sub-systems, and then to combust the de-oxygenated fuel in the or each combustor.

Abstract: A method of assembling a rotor stack comprising a plurality of component parts, the method comprising: determining swash measurements for interfacing surfaces of the plurality of parts; calculating a runout estimate for a plurality of relative orientations of the parts; applying an optimisation algorithm to identify an optimal orientation from the plurality of relative orientations based on the runout estimates; and assembling the parts in the optimal orientation.

Abstract: A composite component comprises a plurality of plies and a plurality of pins extending in a direction transverse to the plies. The pins comprise a first region formed from a first material and a second region formed from a second material.

Abstract: A method of supporting a workpiece on a fixture, the workpiece having a first surface and an opposite second surface, and an aperture positioned at a center of the first surface and extending from the first surface to the second surface the fixture having a first end, an opposite second end, and a center portion, the center portion comprising a supporting surface, the second end being adapted to be mounted in a lathe, the supporting surface comprising an annular recess, the annular recess accommodating a supporting medium, the second surface of the workpiece being in intimate contact with the supporting medium, the method comprising the steps of: (i) mounting the fixture in the lathe; (ii) locating the aperture on the first end of the fixture; and (iii) securing the workpiece on the fixture, with the second surface of the workpiece being coplanar with the supporting surface of the fixture.

Abstract: A forging apparatus and method is disclosed in which a punch 260 is held in a press 210, 220 and propelled towards a billet 250 by a ram 240. The ram 240 is separate from the punch 260. Thus, any axial misalignment between the ram 240 and the press 210, 220 in which the billet is held, for example due to the extremely high loads involved, has no affect on the direction and position of the impact force the punch 260 transmits to the billet 250. This helps to prevent unwanted forces and bending moments in the punch 260, thereby preventing breakage of the punch 260.

Abstract: A control system is provided for performing staging control of a multi-stage combustor of a gas turbine engine. The fuel is fed to the combustor by a fuel supply system comprising: a plurality of fuel manifolds distributing fuel to respective stages of the combustor, a fuel metering valve operable to control the rate at which fuel passes to the fuel manifolds, and an actuating arrangement which splits the fuel flow from the fuel metering valve between the fuel manifolds. The control system includes a fuel pressure sensor arrangement which senses the fuel pressure at entry to the actuating arrangement, and/or in one or more of the fuel manifolds. The control system further includes a controller which repeatedly: calculates a fuel split between the fuel manifolds based on the sensed fuel pressure(s), and issues a command signal to the actuating arrangement to implement the calculated fuel pressure-based fuel split.

Abstract: A panel attachment system includes a panel, a casing, and a plurality of hangers that enable the panel to be secured in a pre-determined position relative to the casing. Each of the hangers is formed as an elongate strip having a single corrugation, with each hanger having a center portion, a first end portion, and an opposite second end portion. The plurality of hangers are positioned in length-wise alignment, with the first end portion of each hanger being attached to the second end portion of an adjoining hanger. The attached first and second end portions are secured to the casing, and the center portion of each hanger is secured to the panel to thereby secure the panel in a pre-determined position relative to the casing.

Abstract: A seal segment is positioned, in use, radially adjacent the rotor. The seal segment has first and second circumferentially spaced passageways each of which extends in the fore and aft direction. In use, a first support bar is contained within the first passageway, and a second support bar is contained within the second passageway. The first and second support bars being mountable to complementary formations provided by the casing of the engine. The first passageway is configured such that the seal segment is fixed relative to the first support bar in the radial and circumferential directions. The second passageway is configured such that the seal segment is fixed relative to the second support bar in the radial direction but allows relative movement of the seal segment and the second support bar in the circumferential direction to accommodate differential thermal expansion of the seal segment and the casing.

Abstract: An actuation system 100 comprises a fluid supply 130 that is fluidly connected to a position control actuator 110. The output of the position control actuator is determined by the fluid supply. The fluid supply is controlled by a piezoelectric actuator 150.

Abstract: Methods, apparatus, computer programs, and non-transitory computer readable storage mediums for repairing an aerofoil of a gas turbine engine A method of repairing an aerofoil of a gas turbine engine, the method comprising: controlling machining of at least one of: a first aerofoil and a second aerofoil; the machining causing an increase in a throat area defined by the first aerofoil, the second aerofoil, a first platform and a second platform, the first aerofoil and the second aerofoil being arranged to couple to the first platform and to the second platform; and controlling provision of a coating to at least one of the first platform and the second platform subsequent to controlling machining to reduce the throat area.

Abstract: A sealing arrangement (30) for providing sealing between a first structure (10), e.g. a rotor shaft, and a second structure (15), e.g. a portion of a casing, of an engine, and between first (HP) and second (LP) pressure regions located between the first (10) and second (15) structures, the first pressure region (HP) being at a relatively higher pressure than the second pressure region (LP), and the first structure (10) being moveable relative to the second structure (15) along an axis, wherein the sealing arrangement (30) comprises: a sealing member (20), e.g.

Abstract: Described is a gas turbine engine, comprising: a first chamber and a second chamber separated by a partition wall; wherein the partition wall includes a stationary element and a rotating element separated by a seal and either of the stationary element and the rotating element of the partition wall is segmented by a levered joint, wherein the levered joint includes a lever having a trigger plate, a fixture portion and a fulcrum portion; and, the other of the stationary element and rotating element includes a hammer which is axially aligned and separated from the trigger plate in a first position, and forcibly contacts the hammer portion in a second position so as to create a moment on the lever via the trigger plate, the moment forcing the levered joint apart.

Abstract: A turbine disc assembly comprises a turbine disc mounted coaxially on a shaft and, in use, arranged in the path of a hot work fluid flow. A cover plate is axially displaced from the turbine disc in a direction upstream with respect to the work fluid flow. The cover plate comprises a radially inner annular disc component and a radially outer annular disc component, the annular disc components are arranged coaxially with each other.

Abstract: A combustion chamber includes at least one annular wall which includes at least one box like structure and each box like structure includes an inner wall, outer wall, upstream end wall and downstream end wall. The inner wall is spaced radially from the outer wall and the outer wall has a plurality of apertures for the supply of coolant into the box like structure. The inner wall, the outer wall, the upstream end wall and the downstream end wall are integral. The upstream end of the annular wall has features to secure the annular wall to an upstream ring structure and a downstream end of the annular wall has features to mount the annular wall on a downstream ring structure. The inner wall has at least one slot extending through the full thickness of the inner wall to accommodate differential thermal expansion between the inner wall and the outer wall.

Abstract: A gas turbine including: a wall component having a gas-facing surface bounding the main gas path; a male-female sealing attachment having a male or female part in which: the male-part includes a component having a main-body, which has first and second arms extending in a common direction and either side of a mid-line plane, wherein the arms are convexly curved in relation to the mid-line plane so as to provide a contact-portion along the length of the arm, the contact-portion being furthest from the mid-line plane; and, the female-part includes a component having a main-body, which includes first and second arms extending therefrom in a common direction and either side of a mid-line plane, wherein the first and second arms are concavely curved in relation to the mid-line plane so as to provide a contact-portion along the length of the arm, the contact portion being closest to the mid-line plane.

Abstract: A panel for lining a gas turbine engine fan casing includes a honeycomb core sandwiched between a backing skin and an outer skin. The backing skin is attached to an inner surface of the casing such that the outer skin forms a radially inward facing surface of a fan duct of the engine. The panel is joined along its sides to similar neighbouring panels such that, in use, the joined panels form a row of panels along the inner surface of the casing. The outer skin or the backing skin includes two face sheets bonded on top of each other, which are arranged such that their edges along each panel side that joins to a neighbouring panel are staggered in the direction of the row. The interfaces between the abutting face sheet edges are therefore correspondingly staggered in the direction of the row.

Abstract: A method is provided of bonding a first component to a second component. The method includes: locating the first component against the second component to form an interface between the components, a curable adhesive being provided at the interface; locating a pressurisable, fluid-filled bladder against the first component such that the first component is sandwiched between the second component and the bladder; locating a backing member against the bladder such that the bladder is sandwiched between the backing member and the first component; pressurising the bladder such that a consolidating pressure is exerted by the bladder on the first component to conform the first component to the second component; and curing the adhesive while the first component is conformed to the second component by the consolidating pressure.

Abstract: A composite component includes a component body and a datum feature. The datum feature projects in a first direction from a surface of the component body; the component further includes a plurality of pins extending generally in the first direction so that a first end of each pin is engaged in the component body and a second end of each pin is engaged in the datum feature. The datum feature is removable from the component so as to leave the first ends of the pins engaged with the component body. The first ends of the pins may be used to identify and locate the position of the original datum feature, when the component requires repair or other attention.