Abstract: A pulsed pressure, heat recovery system includes a pressure vessel for holding a vaporisable first fluid. The vessel contains a heat exchanger, and provides communication to the heat exchanger for flow of a heated second fluid. The heat exchanger enables heat transfer from the second fluid to vaporise the first fluid. The system also includes a flow loop for the first fluid extending from an outlet of the vessel to an inlet to the vessel, having in series: a first non-return valve, a turbine and a second non-return valve. The first non-return valve allows the vaporised first fluid to flow from the vessel to the turbine when the pressure of the vaporised first fluid in the vessel exceeds a predetermined limit. The turbine extracts energy from expansion of the vaporised first fluid. The second non-return valve prevents flow reversal around flow loop between the turbine and the inlet.

Abstract: A process for producing Co, Al alloyed NdFeB nanoparticles, by a microwave assisted combustion process, followed by a reduction diffusion process, includes the steps of: preparing a first solution of boric acid dissolved in 4 N HNO3, dissolving iron nitrate nonahydrate, neodymium nitrate hexahydrate, cobalt nitrate hexahydrate, aluminium nitrate, the first solution in deionized water to form a second solution, adding glycine to the second solution in a molar ratio of 1:1 to form a third solution, subjecting the third solution to microwave radiation, thereby forming an first powder of NdFeCoAlB oxides, mixing the first powder with calcium hydride in a mass ratio of 1:1.1 (NdFeCoAlB oxides:CaH2) to form a second powder, compacted into a powder block, annealing the second powder in a vacuum furnace, washing the annealed second powder with a solution of ethylenediaminetetraacetic acid; and vacuum drying the second powder.

Abstract: There is disclosed a variable vane actuation arrangement 100, 200 comprising a crankshaft 48, 148 comprising a crank web 50,150 and a unison ring assembly 45 comprising a unison ring 34 moveable to vary the pitch of a plurality of variable vanes 26. A connector 42 is fixed with respect to the unison ring 34. The crank web 50, 150 and the connector 42 cooperate by a pin 56—slot 52, 152 mechanism configured so that rotation of the crankshaft 48, 148 causes rotation of the unison ring 34. There is further disclosed a gas turbine engine with a variable vane actuation arrangement.

Abstract: A method of lifing a mechanical component is provided. The method includes: (a) providing a model of the component in which the component is divided into a plurality of regions, and (b) performing consecutively, for each of a consecutive series of actual or virtual missions, the sub-steps of: (b-i) determining the number of operational cycles in the most recent actual or virtual mission for each region, (b-ii) determining a respective unmodified additional cumulative risk associated with each region, (b-iii) determining a respective modified additional cumulative risk associated with each region, (b-iv) determining an updated total modified cumulative risk associated with each region, and (b-v) summing the updated total modified cumulative risks of the regions to determine a modified risk of failure of the component.

Abstract: A case cooling calibration system for a gas turbine engine includes a rotor casing, and a stage, rotatably mounted within the rotor casing. The rotor-casing includes in-series fluid communication, a duct, a flow control valve, and a manifold. The valve regulates an air flow through the duct to the manifold, which is arranged radially outwardly around the casing radially coplanar with the rotor stage. A temperature sensing apparatus is positioned on the rotor casing, radially outwardly of the rotor stage. A controller regulates the valve in a stepwise manner providing a variable cooling air-flow to the rotor-casing. A processor calculates a correction depending on a comparison between the rotor casing temperature and a predicted rotor-casing temperature for a given engine power condition. An engine controller controls the valve depending on the correction characteristic to maintain a predetermined operational radial clearance between the rotor-stage and the rotor-casing.

Abstract: The present disclosure provides a rotary friction welding process including: providing an outer axisymmetric workpiece having a front first annular weld surface at a radially inward extent and a rear first annular weld surface at a radially inward extent; providing a front inner axisymmetric workpiece, the front inner workpiece having a front second annular weld surface at a radially outward extent of the front inner workpiece; providing a rear inner axisymmetric workpiece, the rear inner workpiece having a rear second annular weld surface at a radially outward extent of the rear inner workpiece; and rotary welding the workpieces together.

Abstract: A method of forming an article for finish fabrication into a fan outlet guide vane of a turbofan engine is provided.

Abstract: A method of manufacturing a winding assembly for an electrical machine, the method comprising: selecting (S1) a mathematical function defining the spatial separation between adjacent turns of a winding path, the mathematical function dependent on one or more parameters of the electrical machine and/or of the anticipated operating environment of the electrical machine; forming (S2), by three-dimensional, 3D, printing, an electrically insulating body comprising a channel defining the winding path in accordance with said function, the channel having an inlet and an outlet; heating (S3) the electrically insulating body to a temperature above the melting point of an electrically conducting material; flowing (S4) the electrically conducting material through the inlet to the outlet to fill the channel; and cooling the electrically insulating body to solidify the electrically conducting material within the channel, thereby forming said winding assembly.

Abstract: A turbofan engine has: an engine core producing a core exhaust flow; an upstream fan; a bypass duct carrying a bypass air flow produced by the fan; an exhaust assembly. The turbofan engine afterburner system has: a core plug; second core flow duct, and entrance(s) from the first core flow duct for diversion into the second of a portion of the core exhaust flow, and exit for re-joining the diverted portion of the core exhaust flow to the undiverted portion of the core exhaust flow; door(s) open during normal operation of the engine but closable, during a reheat operation, to block the entrances to the second core flow duct; and fuel injector(s) and igniter(s) operable, during the reheat operation, to inject and ignite fuel within the second core flow duct, providing a reheat flow into the core exhaust flow from the exit of the second core flow duct.

Abstract: A Lubrication system for an engine component of a gas turbine engine, such as a planetary gearbox. The system comprises a main lubrication system comprising a main tank configured to supply lubricant to the engine component, and a main reservoir configured to collect lubricant scavenged from the engine component after lubrication; and an auxiliary lubrication system comprising an auxiliary reservoir configured to collect lubricant scavenged from the engine component after lubrication and to supply scavenged lubricant to the engine component. Main reservoir comprises an interior and the auxiliary reservoir is located within the interior of the main reservoir. The auxiliary reservoir comprises an upper portion, a lower portion and a lubricant pickup region, the upper portion comprising an opening arranged to permit lubricant to overflow into the main reservoir, and the lower portion of the auxiliary reservoir being shaped to cause lubricant to drain towards the lubricant pickup region.

Abstract: The present disclosure provides a fuel metering system for a gas turbine engine, the fuel metering system comprising: a fuel supply line; a fuel metering valve configured to pass an amount of fuel received from the fuel supply line to the gas turbine engine; a spill line configured to receive excess fuel from the fuel supply line; a spill valve provided in the spill line and configured to control the flow of fuel through the spill line; an engine control unit configured to control the position of the spill valve; a sensor configured to measure the position of the spill valve; wherein the engine so control unit is further configured to identify an uncommanded increase in fuel flow by comparing an expected position of the spill valve to a position of the spill valve measured by the sensor.

Abstract: Apparatus for controlling a power generation system, the apparatus comprising a controller configured to: identify a trigger indicative of a future change in electrical power output by the power generation system to a first power level; control the power generation system to change electrical power output to a second power level in response to the trigger, the second power level being equal to, or different from the first power level; and control supply of at least a portion of the electrical power output from the power generation system at the second power level to an electrical energy storage system to charge the electrical energy storage system.

Abstract: A hyper redundant robot comprising: a first disk; a second disk positioned adjacent to the first disk, the first disk and the second disk having a longitudinal axis; a first joint arrangement positioned between the first disk and the second disk, the first disk and/or the second disk being in sliding contact with the first joint arrangement to enable the first disk and the second disk to rotate relative to one another; and a second joint arrangement positioned between the first disk and the second disk, the second joint arrangement being less stiff than the first joint arrangement.

Abstract: A cutting tool comprises a tool body having a first end and a second end, and a longitudinal axis extending between the first end and the second end. The first end comprises two or more cutting portions, with each of the cutting portions comprising a cutting edge and a flank surface. Each cutting edge extends radially outwardly from a centre region of the first end to a perimetral edge of the first end, with the cutting edge being angled relative to the longitudinal axis. Each flank surface extends circumferentially from the cutting edge. Each of at least two of the two or more flank surfaces comprises an abrasive portion extending over at least a part of the respective flank surface and each abrasive portion comprises a plurality of abrasive features.

Abstract: A gas turbine engine comprises a compressor driven by a shaft, and a reference starting schedule, the compressor having a reference stability boundary, with the reference starting schedule defining a reference working line. A method of starting the gas turbine engine is described in which the method comprises the steps of: (i) accelerating the rotational speed of the shaft towards an engine idle speed; (ii) defining for the compressor, as the rotational speed increases, an operational working line; and (iii) modifying at least one operating parameter of the gas turbine engine as the rotational speed increases such that for a rotational speed, an operational working line is closer to the reference stability boundary than the reference working line is to the reference stability boundary.

Abstract: The present invention provides a sealing element for an air-riding seal system. The seal has a mounting portion for mounting on a rotor and a sealing portion having a sealing face for facing a second sealing element. A bridging portion is provided extending radially between the mounting and sealing portions. The bridging portion allows axial displacement between the mounting portion and sealing portion and/or angular variation of the sealing face relative to the mounting portion and may be a pliable/flexible membrane structure allowing said axial displacement/angular variation by flexing.

Abstract: A windage shield system comprises first and second hollow cylindrical elements, the longitudinal axes of the outer and inner surfaces of each element being parallel and mutually displaced. The elements are mounted to the downstream end of a fan disc such that the longitudinal axes of the inner surface of the first element and the outer surface of the second element coincide with the rotational axis of the disc. The centres of mass of the elements are mountable with azimuthal offsets ?1, ?2 with respect to the fan disc, each being selectable from a large number of values in the range 0° to 360°. The first element is integral with a windage shield. The system allows a fan disc to be provided with a windage shield and the resulting assembly to be balanced at its rear plane in cases where access to the rear of the fan disc is difficult.

Abstract: A valve assembly comprising: a fluid flow passage to permit the flow of a fluid through the valve assembly; a valve seat; and an actuator assembly. The actuator assembly comprises: a valve member moveable relative to the valve seat between a first position in which the valve member is at least partially engaged with the valve seat to at least partially block the fluid flow passage, and a second position in which the valve member is remote from the valve seat; an actuator body in a fixed position relative to the valve seat; and a metal bellows that is attached to the valve member and to the actuator body and is disposed within the fluid flow passage. The valve member of the actuator assembly is moveable relative to the actuator body and extends around the actuator body such that the actuator body is disposed within the valve member.

Abstract: A compressor disc includes a diaphragm portion connected to a mounting disc portion at its distal end and a cob portion at its proximal end. The cob portion having a leading edge with a shoulder section connected to an edge section at point X, a trailing edge with a shoulder section connected to an end section at point Y, and a base. Point X is offset relative to point Y in relation to the distance to the cob portion base. Point X of the cob portion may be offset relative to Point Y of the cob portion by 1 to 10 mm. Alternatively Point X of the cob portion is offset relative to point Y of the cob portion by 2 to 8 mm. the cob portion may have asymmetric widths relative to a centreline extending through a plane at the centre of the diaphragm and through into the cob.

Abstract: A compressor disc includes a diaphragm portion connected to a mounting disc portion at its distal end and a cob portion at its proximal end. The cob portion having a leading edge with a shoulder section connected to an end section at Point X, and a trailing edge with a shoulder section connected to an end section at point Y, and a base. The cob portion is asymmetrical about a centreline that extends along a plane representing the geometric centre of the diaphragm portion and through to the base of the cob portion, dividing the diaphragm and cob portion into two respective cob sections, which have surface areas that differ by no more than 10%. The distance between the base of the cob portion and Point X of the leading edge may differ from the distance between the base of the cob portion and Point Y of the trailing edge.