Abstract: A rotor is provided comprising a centre of mass and a rotational axis and a rotor sealing component extending circumferentially around the rotor for sealing between the rotor and a stator, wherein the centre of mass of the rotor is coincident with the rotational axis, and material of the rotor sealing component is not evenly distributed around its circumference. A stator sealing component in which the material is not evenly distributed around its circumference is also provided.

Abstract: A combustion chamber assembly comprises a combustion chamber and a plurality of nozzle guide vanes. Each nozzle guide vane comprises an inner platform, an outer platform and an aerofoil. The combustion chamber comprises an annular wall which includes at least one box like structure. An outer wall of each box has a plurality of apertures for the supply of coolant into the box and the interior of the box is divided into at least two regions. The upstream end of each box has apertures to supply coolant from a first region of its interior onto an inner surface of the inner wall to form a film of coolant. The downstream end of each box has apertures to supply coolant from a second region of its interior onto a surface of the inner or outer platform of the nozzle guide vanes to form a film of coolant.

Abstract: A method of repairing a composite material, the composite material comprising fibres embedded in a matrix, comprises the steps of: identifying a damaged portion of a composite material; applying thermal energy directly to a section of the composite material including the damaged portion, so as to remove the matrix material whilst retaining the fibres; filling the section of the composite material with replacement matrix material.

Abstract: A gas turbine engine generates noise during use, and one particularly important flight condition for noise generation is take-off. A gas turbine engine has high efficiency together with low noise, in particular from the turbine that drives the fan. The contribution of the turbine noise emanating from the rear of the engine to the Effective Perceived Noise Level (EPNL) is in the range of from 7 EPNdB and 30 EPNdB lower at a take-off lateral reference point than at an approach reference point.

Abstract: A gas turbine engine for an aircraft has an engine core having a turbine, compressor, and core shaft connecting the turbine and compressor; a fan upstream the engine core, the fan having fan blades; and a gearbox. The gearbox receives an input from a core shaft and outputs drive to a fan to drive the fan at a lower rotational speed than the core shaft. The gearbox is an epicyclic gearbox and has a sun gear, planet gears, ring gear, and planet carrier on which the planet gears are mounted. The gearbox has a gear mesh stiffness between the planet gears and the ring gear and a gear mesh stiffness between the planet gears and the sun gear. The gear mesh stiffness between the planet gears and the ring gear divided by that between the planet gears and the sun gear is in the range from 0.90 to 1.28.

Abstract: A gas turbine engine comprises a gearbox including a first epicyclic gearbox and a second epicyclic gearbox. The first epicyclic gearbox comprises a first sun gear meshing with the first planet gears and the first planet gears meshing with a first annulus gear. The second epicyclic gearbox comprises a second sun gear meshing with the second planet gears and the second planet gears meshing with a second annulus gear. An input shaft is arranged to drive the first sun gear and a first planet gear carrier is arranged to drive a propulsor. The first and second annulus gears are fixed to a static structure. A first clutch is arranged between the first planet gear carrier and the second planet gear carrier and a second clutch is arranged between the second sun gear and the input shaft. The gearbox is more efficient at cruise conditions.

Abstract: A planetary gearing includes a sun gear; a plurality of planet gears, a ring gear; and a plurality of planet pins, wherein respectively one planet pin is arranged inside a planet gear, and the planet pin and the planet gear form a lubricated journal bearing. The planet pin includes an axial bore and an inner surface that comprises an axially forward end and an axially rearward end. The inner diameter of the axial bore of the planet pin varies between the axially forward end and the axially rearward end of the inner surface and has a maximum at least at one axial end. The planet pins respectively form a crowning at their abutment surface such that their outer diameter decreases from a maximum outer diameter towards at least an axial end of the abutment surface, and has a minimum at the axial end.

Abstract: A gas turbine engine combustion chamber includes upstream and downstream ring structures and a plurality of circumferentially arranged combustion chamber segments. Each segment extends the full length of the combustion chamber and each segment is secured to the upstream ring structure and is mounted on the downstream ring structure. A frame structure at the downstream end of each segment has multiple spaced radially extending holes. The downstream end of each segment has an axially upstream extending groove and the downstream ring structure has an annular axially upstream extending hook which locates in the groove of each segment. A portion of the downstream ring structure abuts the frame structure of each segment. The downstream ring structure has multiple holes through the portion abutting the frame structure and segment is removably secured to the downstream ring structure by multiple fasteners locating in the holes in the segments and the downstream ring structure.

Abstract: A vehicle controller that is located on a vehicle, the vehicle controller including: a client communications device for communicating, over a satellite link, with a server communications device in a vehicle control centre that is remote from the vehicle controller; and a vehicle control device arranged to control the movement of the vehicle in response to data received by the client communications device over the satellite link, such that the movement of the vehicle in one or more convoys of vehicles is dependent on received data by the client communications device.

Abstract: Turbine vane assemblies incorporating both metallic and ceramic matrix composite materials are provided in the present disclosure. The turbine vane assemblies further include interface components that allow for differing rates of thermal expansion in the ceramic matrix composite components and the metallic components.

Abstract: There is disclosed a method of manufacturing a composite component comprising a main body and an integral flange, the method comprising: applying fibre reinforcement material on a tool having a main body portion and a flange-forming portion to provide a pre-form having first, second and third contiguous regions, the first region corresponding to the main body of the component and the second region corresponding to the integral flange of the component; and causing relative movement between the flange-forming portion and the main body portion so that the second region of the pre-form deforms to form the flange; wherein the relative movement of the flange-forming portion and the main body portion causes sliding movement between the second and third regions of the pre-form and the flange-forming, thereby producing a tension force in at least the second region of the pre-form during forming of the flange.

Abstract: In some examples, a system includes a blade including a blade tip and a blade track or blade shroud segment including a substrate and an abradable coating layer on the substrate. The substrate defines a leading edge and a trailing edge. The abradable coating layer includes a first tapered portion that substantially continuously tapers from a center portion of the substrate toward the leading edge of the substrate, a second tapered portion that substantially continuously tapers from the center portion of the substrate toward the trailing edge of the substrate, and a blade rub portion that extends between the first tapered portion and the second tapered portion. The abradable coating extends from the leading edge to the trailing edge, and the blade tip is configured to contact at least a portion of the blade rub portion upon rotation of the blade.

Abstract: There is described an inspection device for inspecting a slot of a gas turbine engine. The inspection device comprises: an insert for insertion into the slot; a plurality of imaging devices coupled to the insert; and a processor. The insert is movable along a longitudinal axis of the slot. Each of the plurality of imaging devices is positioned adjacent an external surface of the insert and is configured to capture an image of a portion of the slot adjacent the imaging device. The processor is configured to receive data corresponding to the images captured by the plurality of imaging devices. There is also described a method of inspecting a slot using the inspection device.

Abstract: An engine for an aircraft includes an engine core including a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan including a plurality of fan blades; and a gearbox. The gearbox is arranged to receive an input from a core shaft and to output drive to a fan to drive the fan at a lower rotational speed than the core shaft. The gearbox is an epicyclic gearbox and includes a sun gear, a plurality of planet gears, a ring gear, and a planet carrier on which the planet gears are mounted. A ratio of radial bending stiffness of the planet carrier to torsional stiffness of the planet carrier is within a specified range.

Abstract: A pressure relief arrangement for a gas turbine engine comprises a hinged door and a mount spaced from the door. An expandable structure is connected to the door and to the mount such that when the door hinges open the expandable structure expands.

Abstract: The present invention provides a laser welding process and a holding fixture for holding a first and a second body during a laser welding process. A first body and a second body for welding together along at least one weld line to form a joined component are immobilised in the holding fixture by a back clamp and a front clamp of the fixture. A shielding gas is supplied, from respective plenums formed in the back and front clamps, to back and front sides of the component along the weld line. Laser welding the first and second bodies together along the weld line, the laser weld thus-formed penetrating from the front side to the back side of the component.

Abstract: A gas turbine engine includes: an engine core, compressor system, and core shaft. A compressor exit pressure is defined as an average airflow pressure at the exit of the highest pressure compressor at cruise conditions. The core has an annular splitter and bypass flow. Stagnation streamlines around the engine circumference form a streamsurface. A fan is upstream the core with blades having leading and trailing edges, and a radially inner portion within the streamtube. A fan root entry pressure is an average airflow pressure across the radially inner portion leading edge of each fan blade at cruise conditions. An overall pressure ratio, OPR, is defined as the compressor exit pressure divided by the fan root entry pressure. A bypass jet velocity is defined as the jet velocity of air flow exiting the bypass exhaust nozzle at cruise conditions. A jet velocity to OPR ratio is in a range between 4.7 m/s and 7.7 m/s.

Abstract: A gas turbine engine may include a high pressure compressor coupled to a high pressure turbine by a high pressure shaft, a core combustor located downstream of the high pressure compressor and upstream of the high pressure turbine, and a low pressure compressor provided upstream of the high pressure compressor. The low pressure compressor may be configured to direct core airflow to the high pressure compressor and first bypass airflow which bypasses the high pressure compressor, core combustor and high pressure turbine through a first bypass duct. The engine may further include a mixer downstream of the high pressure turbine and low pressure compressor, the mixer being configured to mix the core and first bypass airflows. The engine also may include a re-heat combustor configured to combust fuel with both core airflow and first bypass airflow.

Abstract: A gas turbine engine includes a gearbox including a sun gear, annulus gear, plurality of planet gears and a planet gear carrier. Each planet gear is rotatably mounted in the planet gear carrier by a planet gear bearing. A lubrication system is arranged to supply lubricant to the planet gear bearings and at least one of the sun gear, the planet gears and the annulus gears. The planet gear carrier includes an annular extension. The lubrication system includes an annular member arranged around annular extension to define an annular chamber which is sealed at its ends to the planet gear carrier and which contains a reserve of lubricant. The annular member has an inlet to supply lubricant into the annular chamber and the planet carrier has a first passage to supply lubricant to the sun, planet or annulus gear and a second passage to supply lubricant to planet gear bearings.

Abstract: An electrical machine has a stator with windings, first and second rotors, and an electrical output regulator. The first rotor carries alternating polarity first field magnets, such that, on drive mechanism rotation, the windings interact with the magnetic flux produced by the first magnets to create an EMF. The second rotor carries alternating polarity second field magnets, and has first and second rotational positions to reduce and increase, respectively, the magnetic flux energy. The electrical output regulator regulates a current from the windings to produce a torque on the rotors, as the drive mechanism increases from zero rotational speed, the torque rises above a threshold level that moves the second rotor from the first to the second rotational position, and, as the drive mechanism further increases the rotational speed, the torque peaks and then drops below the threshold level to move the second rotor back to the first rotational position.