Abstract: An article for use in a high-temperature environment that includes a substrate including a superalloy material, a ceramic, or a ceramic matrix composite, and an abradable coating on the substrate, the abradable coating including a rare earth silicate and a dislocator phase, the dislocator phase forms one or more distinct phase regions in the abradable coating and comprises at least one of hafnium diboride (HfB2), zirconium diboride (ZrB2), tantalum nitride (TaN or Ta2N), tantalum carbide (Ta2C), titanium diboride (TiB2), zirconium carbide (ZrC), hafnium carbide (HfC), tantalum diboride (TaB2), hafnium nitride (HfN), or niobium carbide (NbC).

Abstract: An electrical machine comprising a two-part rotor formed of a first rotor part and a second rotor part. The first rotor part includes a conical section and is mounted to a shaft of the machine. The second rotor part has a bore including a complementary conical section. The second rotor part is configured to displace axially between a first state, in which it is engaged with the first rotor part to form the rotor of the electrical machine, and a second state, in which it is axially disengaged from the first rotor part. Also a clutch having an engaged state and a disengaged state. When the clutch is in one of its states the second rotor part is in its first state and switching the clutch to the other of its states axially displaces the second rotor part to its second state.

Abstract: A computer-implemented method comprising: controlling input of at least a portion of a first training data set into a first machine learning algorithm, the first training data set including: data quantifying damage to a first compressor; and data quantifying a first operating parameter of the first compressor; executing the first machine learning algorithm; receiving data quantifying the first operating parameter as an output of the first machine learning algorithm; and training the first machine learning algorithm using: the received data output from the first machine learning algorithm; and data quantifying the first operating parameter of the first compressor, the trained first machine learning algorithm being configured to enable determination of operability of a second compressor of a gas turbine engine.

Abstract: A method of friction welding a first component to a second component, the method having the steps of: rotating the first component relative to the second component about a rotation axis; and bringing the first component into contact with the second component; wherein, while the first component and the second component are in contact, a first average force is applied during a first stage of the friction welding process and a second average force is applied during a second stage of the friction welding process; and the second average force is different from the first average force.

Abstract: A computer-implemented method comprising: receiving an operability determination for a compressor of a gas turbine engine, the operability determination being determined using an output from a machine learning algorithm trained using data quantifying damage received by compressor blades of a compressor; determining one or more actions to be performed using the received operability determination; and generating control data using the determined one or more actions.

Abstract: A computer-implemented method comprising: controlling input of data quantifying damage received by a compressor of a gas turbine engine into a first machine learning algorithm; receiving data quantifying a first operating parameter of the compressor as an output of the first machine learning algorithm; and determining operability of the compressor by comparing the received data quantifying the first operating parameter of the compressor with a threshold.

Abstract: A method of joining a first component to a second component at respective connection surfaces, comprising, in order, applying a local surface treatment to the connection surface of at least one of the first and second components in order to locally alter the microstructure to a depth of between 60 ?m and 10 mm below the connection surface; and joining the first component to the second component using a welding process.

Abstract: A gas turbine engine that includes a fan blade having a tip, a root, a pressure side, a suction side, a trailing edge and a leading edge, the fan blade including a laminate body defined by a plurality of plies comprising reinforcement fibres, wherein an angle of the fibres in the plies from the trailing edge to the leading edge at the suction side and/or the pressure side of the blade are arranged such that the laminate body is unbalanced so that, during rotation of the fan blade, the fan blade deforms such that a centre of mass of the blade rotates about a centre of rotation of the fan so as to move the centre of mass towards a balanced position.

Abstract: A gas turbine engine for an aircraft including: 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; a gearbox that can receive an input from the core shaft and output drive to the fan so as to drive the fan at a lower rotational speed than the core shaft; and a gearbox support arranged to at least partially support the gearbox within the engine. A flight cycle ratio of: the ? ? torsional ? ? shear ? ? stress ? ? of ? ? the ? ? gearbox ? ? support ? ? at maximum ? ? takeoff ? ? conditions the ? ? torsional ? ? shear ? ? stress ? ? of ? ? the ? ? gearbox ? ? support ? ? at cruise ? ? conditions is less than or equal to 3.20. A method of operating the gas turbine engine is also disclosed.

Abstract: A flow splitter for a gas turbine engine comprising one or more boreholes formed in an exterior surface of the flow splitter. A gas turbine engine comprising a flow splitter.

Abstract: There is disclosed a method of manufacturing a fan blade for a gas turbine engine, the method comprising: providing a root insert comprising quasi-isotropic short fibre reinforced resin, providing a first sub-laminate of a fibre-reinforcement pre-form for the fan blade on a first mould surface, placing the root insert on the first sub-laminate at a position corresponding to a root of the fan blade, providing a second sub-laminate of the pre-form over the root insert and the first-sub-laminate, so that the root insert is at an intermediate position between the first and second sub-laminates; and applying heat and pressure to form the pre-form.

Abstract: A gearbox includes a sun gear, a plurality of planet gears, an annulus gear and a planet carrier. The planet carrier includes a first ring, second ring spaced axially from the first ring, a plurality of circumferentially spaced axles and a plurality of circumferentially spaced support structures extending axially between and secured to the first ring and second ring. Each planet gear is rotatably mounted on a respective one of the axles. The first ring has a plurality of circumferentially spaced recesses and the second ring has a plurality of circumferentially spaced recesses. Each recess in the second ring is aligned with a corresponding one of the recesses in the first ring. A first end of each support structure locates in a recess in the first ring. A second end of each support structure locates in a recess in the second ring. Each support structure comprises a fused powdered material.

Abstract: A combustion chamber comprises an upstream end wall structure and inner and outer annular wall structures. The upstream end wall structure comprises an upstream wall and a plurality of circumferentially arranged heat shields secured to the upstream wall. The upstream wall has a plurality of circumferentially spaced fuel injector apertures. Each heat shield has radially outer and radially inner ends and a fuel injector aperture aligned with a corresponding fuel injector aperture in the upstream wall. The radially outer and inner ends of each heat shield have outer and inner rails spacing the heat shield from the upstream wall. The radially outer and inner ends of each heat shield have first and second pluralities of circumferentially spaced apertures extending there-through and through the associated outer and inner rails to direct coolant over the surface of the outer and inner annular wall structures to form respective films of coolant.

Abstract: A control system for a gas turbine engine includes an engine core, the engine core including combustion equipment, a turbine, a compressor, and a core shaft connecting the turbine to the compressor. The control system includes at least one variable stator vane for controlling the angle at which gas enters the engine core, and there is a bypass passage within the engine core for directing gas flow to bypass the combustion equipment.

Abstract: A gas turbine engine includes an engine core including: a compressor system including first, lower pressure compressor, and second, higher pressure compressor; and inner and outer core casings that define a core working gas flow path (A) therebetween, which has an outer radius that defines a gas path radius. The outer core casing includes a first flange connection that: has a first flange radius, is arranged to allow separation of the outer core casing at an axial position thereof, and is the first flange connection that is downstream of an axial position defined by the axial midpoint between the mid-span axial location on trailing edge of the most downstream aerofoil of first compressor and mid-span axial location on leading edge of the most upstream aerofoil of the second compressor. A gas path ratio of: first ? ? flange ? ? radius gas ? ? path ? ? radius is equal to or greater than 1.10.

Abstract: A pressure relief arrangement for a gas turbine engine comprises a panel and a plurality of pressure relief mechanisms provided in the panel. The mechanisms have a first configuration and a second configuration. In the first configuration the panel is sealed to prevent fluid flow through the panel in a thickness direction and in the second configuration the mechanisms are arranged so that a plurality of holes are provided in the panel so fluid can flow through the panel in a thickness direction.

Abstract: A turbine shroud assembly includes a blade track, a multi-piece carrier and a mount assembly. The carrier includes a fore body and an aft body. Attachment pin of the mount assembly extends between fore body and aft body and through an eyelet in an attachment post of the blade track.

Abstract: A gas turbine engine for an aircraft is provided. The gas turbine engine comprises an engine core comprising a compressor, a combustor, a turbine, and a core shaft connecting the turbine to the compressor. The gas turbine engine further comprises a fan located upstream of the engine core, the fan comprising a plurality of fan blades, the fan generating a core airflow which enters the engine core and a bypass airflow which flows through a bypass duct surrounding the engine core. The gas turbine engine further comprises a circumferential row of outer guide vanes located in the bypass duct rearwards of the fan, the outer guide vanes extending radially outwardly from an inner ring which defines a radially inner surface of the bypass duct.

Abstract: A fuel spray nozzle arrangement for a combustor, the fuel spray nozzle arrangement comprising a fuel spray nozzle connected to a feed arm, wherein the feed arm comprises an aerofoil.

Abstract: A method of reassembling a gas turbine engine including steps to support a core engine on a core stand and support a fan case on a fan stand that includes a base frame coupled a fan case frame by a hinge. The fan case frame is arranged to (i) rotate about an axis of the hinge between abutting the base frame and being perpendicular to the base frame, and (ii) tilt about a yaw axis perpendicular to the hinge, which is located in a plane of the fan case frame. The method includes rotating and tilting the fan case frame to align the fan case and core engine, translating at least one of the core engine and the fan case into axial abutment, coupling the fan case and the core engine to reassemble the gas turbine engine, and decoupling the fan case from the fan stand.