Abstract: A combustion staging system includes a splitting unit which receives a metered fuel flow and controllably splits the received fuel flow into pilot and mains flows. Pilot and mains fuel manifolds distribute fuel from the splitting unit to the pilot and mains stages. The splitting unit selects and deselects pilot-only operation. Both pilot and mains manifolds are selectable for pilot and mains operation. A cooling flow recirculation line has a delivery section arranged to provide a cooling flow of fuel to the mains manifold when it is deselected during pilot-only operation. Cooling flow enters the delivery section from a high pressure fuel zone of the engine and exits the return section to a low pressure fuel zone of the engine. A controller adjusts the splitting unit during pilot-only operation to partially select the mains manifold thereby increasing the pressure in the mains manifold to meet a target fuel pressure therein.

Abstract: A combustion chamber system has pilot and main fuel manifolds, and pilot and main fuel nozzles. Each pilot nozzle is connected to the pilot manifold. Each main nozzle is connected to the main manifold. A greater total amount of fuel is supplied to the pilot nozzles than to the main nozzles. A greater amount of fuel is supplied to pilot nozzles at, or in, a first region of the combustion chamber than to pilot fuel nozzles at, or in, a second region. A greater amount of fuel is supplied to the main nozzles at, or in, the first region than to the main nozzles at, or in, the second to improve combustion efficiency, weak extinction and relight of the combustion chamber in a first mode of operation. A greater total amount of fuel is supplied to the main nozzles than to the pilot nozzles in a second mode of operation.

Abstract: The present invention provides a sensor system for measuring a parameter (e.g. volume, temperature or pressure) of a target, the system comprising a diaphragm, a sensor for measuring the axial spacing between the sensor and the diaphragm, and an axially adjustable mount. The mount has a first axial end for mounting the diaphragm which is axially movable relative to the sensor and an opposing, second axial end which is axially fixed relative to the sensor. The diaphragm and mount define a chamber for receiving the target or for being received within the target. In use, the axial spacing between the first axial end and the second axial end of the mount and thus the axial spacing between the diaphragm and sensor varies as a result of a change in the parameter differential across the diaphragm.

Abstract: A transmission system for transmitting a change of speed between two rotating shafts, includes a planetary gear box having a sun gear arranged for rotation with a first shaft travelling at a first speed. Planet gears contained within a ring gear are arranged to orbit the sun gear when the sun gear rotates and the ring gear is in a fixed position. Each planet gear is mounted for rotation on a centrifugal carrier. An output carrier includes a body having arms and the arms are each aligned with an axis of rotation of a planet gear and held to the centrifugal carrier by one or more supports extending in a radial plane. An output shaft extends from the body in coaxial alignment with the input shaft. A connector which is stiff in a radial dimension but flexible under torsional load is arranged between the output carrier and the centrifugal carrier.

Abstract: A composite component comprising a plurality of plies. A first set of pins extend in a direction transverse to the plies and a second set of pins extend in a direction transverse to the plies. The pins of the first set are made of a different material to the pins of the second set.

Abstract: A cooling system for a gas turbine engine. The system includes a fuel air heat exchanger with a fuel passage that is in thermal contact with an engine cooling air passage. The system further includes a fuel deoxygenator located upstream of the fuel air heat exchanger and configured to deliver deoxygenated fuel to the fuel air heat exchanger fuel passage. The system also includes a valve configured to moderate engine cooling air flow to the engine cooling air passage.

Abstract: The invention concerns an article (20) formed of a ceramic matrix composite structure having a plurality of ceramic fiber layers (22) and a binder material (24) interspersed throughout said layers. The ceramic matrix composite material may be sintered. The ceramic fiber layers undulate relative to one or more outer surfaces (38;40) of the article. Thus support features (48) within the article are able to share a load in use between a plurality of layers. The invention may be suited to engine components such as turbine seal segments in a gas turbine engine.

Abstract: A gas turbine engine assembly adapted to separate a high pressure zone from a low pressure zone includes a seal assembly configured to block gasses from passing through the interface of two adjacent components. The seal assembly includes a rod.

Abstract: This disclosure describes a wall arrangement for a gas turbine engine, comprising: an annular wall comprising a plurality of circumferential wall segments, adjacent wall segments having opposing first and second end wall portions which define a separating gap therebetween, the gap including a saddle portion which faces radially outwards and comprises a first sealing face on the first end wall portion and a second sealing face on the second end wall portion; and, a longitudinal seal member having a curved sealing surface located within the saddle portion, wherein the curved sealing surface contacts the either or both first and second sealing faces along the length of the saddle portion in use, wherein the seal member includes axially compressible segments which allow the seal member to bend longitudinally.

Abstract: A procedure defining a balancing strategy includes: providing a computer model which predicts the vibration amplitude at a given axial position along the spool when the spool is rotated at a given rotational speed; using the model to predict respective vibration amplitudes at the given axial position for different axial positions of a unit unbalance applied to the spool; plotting the predicted vibration amplitudes as data points on a graph of vibration amplitude against axial position of the applied unit unbalance; using the graph to identify axial positions which are more or less likely to contribute to flexing of the spool at the given rotational speed when mass is added or removed from the first rotor module to reduce imbalances at the axial positions; and defining a balancing strategy based on the identification.

Abstract: This document discloses a wall arrangement for a gas turbine engine, comprising: an annular wall comprising a plurality of circumferential wall segments, adjacent wall segments having opposing first and second end wall portions which define a separating gap therebetween, the gap including a saddle portion which faces radially outwards and comprises a first sealing face on the first end wall portion and a second sealing face on the second end wall portion; and, a longitudinal seal member having a curved sealing surface located within the saddle portion, wherein the curved sealing surface contacts either or both first and second sealing faces along the length of the saddle portion in use, wherein the seal member includes one or more axial restraint features which engage with a corresponding feature of the wall segment or a supporting structure thereof.

Abstract: A mass simulator to determine unbalance of a rotor module in a balancing machine that simulates the mass of an adjacent rotor module. The mass simulator has a shaft extending along an axis of rotation of the mass simulator. The shaft has an attachment interface at one end for attaching to a corresponding interface, and has a support portion at the opposite end which is rotatably supportable in the balancing machine. The mass simulator has a mass body mounted to the shaft by a release mechanism allowing the mass body to be repeatably mounted to and dismounted from the shaft. The mass simulator being attached to the rotor module at the attachment interface and the assembly of the attached mass simulator and rotor module located in the balancing machine to determine unbalance of the rotor module with the mass body mounted to, and dismounted from, the shaft.

Abstract: A supercritical working fluid closed cycle heat engine includes, in fluid flow series: a heat source heat exchanger configured to raise the temperature of a working fluid; an expander configured to extract work from the working fluid; a condenser configured to exchange heat between the working fluid and the cooling medium; and a separator configured to separate liquid phase working fluid from gaseous phase working fluid and deliver gaseous phase working fluid to a gaseous compressor and liquid phase working fluid to a fixed displacement liquid pump, the compressor and pump being arranged in parallel. Each of the compressor and fixed displacement pump are configured to return fluid to the heat source heat exchanger. The compressor comprises a variable inlet guide vane and a variable outlet diffuser vane.

Abstract: A gas turbine engine bladed rotor arrangement comprises a rotor, a plurality of rotor blades and a plurality of lock plates. The rotor blades are mounted in circumferentially spaced axially extending slots in the periphery of the rotor. A plurality of lock plates are arranged at a first axial end of the rotor. The radially outer ends of the lock plates engage corresponding grooves defined by radially inwardly extending flanges on the platforms of the rotor blades. The radially inner ends of the lock plates also engage a circumferentially extending groove. The radially outer end of at least one lock plate at the first axial end of the rotor has at least one projection extending axially away from the rotor. Each projection locates against a corresponding anti-rotation feature.

Abstract: Described is a wall arrangement for a gas turbine engine, comprising: an annular wall comprising a plurality of circumferential wall segments, adjacent wall segments having opposing first and second end wall portions which define a separating gap therebetween, the gap including a saddle portion which faces radially outwards and comprises a first sealing face on the first end wall portion and a second sealing face on the second end wall portion; and, a longitudinal seal member having a curved sealing surface located within the saddle portion, wherein the curved sealing surface contacts the either or both first and second sealing faces along the length of the saddle portion in use, in which the seal member further includes a plurality of flow passages extending from an outboard side to an inboard side.

Abstract: A double skinned feed or scavenge pipe assembly comprises; an inner pipe (22) and an outer pipe (23) enclosing the inner pipe and defining an annular space (24) between the inner pipe and the outer pipe and a sleeve (28) configured to slip over the outer pipe (23). Complementary threads (29) are provided on an outer wall of the outer pipe (23) and an inner wall of the sleeve (28). A lock, for example in the form of a locking nut (31) is positioned over the outer pipe (23) when the complementary threads (29) of the outer pipe and sleeve are engaged. The configuration of the assembly is such that, in use, the sleeve (28) is slidable between a first position where the inner pipe (22) is accessible and a second position wherein the inner pipe (22) is completely enclosed.

Abstract: An annulus filler, mounted to a rotor disc of a gas turbine engine and bridging the gap between two adjacent blades attached to the rotor disc, is disclosed. The annulus filler, formed from a polymer matrix composite material, includes an outer lid, defining an airflow surface for air drawn through the engine in an axial airflow direction, and a support structure, connectable to the rotor disc, to support the rear of the lid on the rotor disc. The support structure has two support walls extending from opposing lateral sides of the lid to an attachment strap for receiving a hook on the rotor disc, the attachment strap bridging the support walls. Under centrifugal loads, the opposing support walls resiliently deform. Each support wall has a concave rear edge. Each rear edge has a first curved section, a second curved section and a substantially straight section therebetween.

Abstract: Described is an abradable component for a gas turbine engine that includes a base having an outboard side which receives a supply of cooling air in use and an inboard side with a plurality of walls thereon. The walls intersect one another to define an abradable network of open faced cells on a gas washed surface thereof, and at least one of the walls includes one or more through-holes for providing a flow of cooling air from the outboard side to the gas washed surface of the abradable network of open faced cells, when in use.

Abstract: A fan casing for fitment around an array of radially extending fan blades of a gas turbine engine. The fan casing includes an annular casing element; and an annular fan track liner positioned radially inward of the annular casing element. The fan track liner includes an abradable layer and an abrasive layer, the abrasive layer being positioned radially inward of the abradable layer and proximal, in use, to the fan blades.

Abstract: A supercritical working fluid closed cycle heat engine includes, in fluid flow series: a heat source heat exchanger configured to raise the temperature of a working fluid; an expander configured to extract work from the working fluid; a condenser configured to exchange heat between the working fluid and the cooling medium; and a separator configured to separate liquid phase working fluid from gaseous phase working fluid and deliver gaseous phase working fluid to a gaseous compressor and liquid phase working fluid to a fixed displacement liquid pump, the compressor and pump being arranged in parallel. Each of the compressor and fixed displacement pump are configured to return fluid to the heat source heat exchanger. The compressor comprises a variable inlet guide vane and a variable outlet diffuser vane.