Abstract: A fuel system for a hydrogen fueled aircraft propulsion system comprises a tank configured to store hydrogen, a first inductor provided within the tank and configured to heat hydrogen fuel within the tank, and a second inductor provided externally to the tank, and configured to induce a current in the first inductor.

Abstract: A fault detector for a control system that includes a controller, a solenoid driver, a current sensor and a solenoid. The solenoid driver provides a current to the solenoid in response to a control signal provided by the controller to the solenoid driver and the current sensor measures the current provided by the solenoid driver to the solenoid to determine a current measurement. At any moment, the control signal corresponds to one of a demanded zero current, a demanded first current magnitude or a demanded second current magnitude. The fault detector detects a fault based upon a comparison of the current measurement to an expected current range, wherein the expected current range is dependent upon which of the demanded zero current, demanded first current magnitude or the demanded second current magnitude the control system corresponds to at that moment.

Abstract: There is provided a casing assembly for a gas turbine engine comprising: a casing and electrically conductive intumescent material extending around the casing. The intumescent material is being activatable in response to electrical current to expand. The casing assembly comprises an electrical activation line extending around the casing to activate the intumescent material. The activation line extends in a pattern such that an activation area which circumscribes the activation line has an axial extent of at least 50% of the casing and a circumferential extent of at least 50%, to thereby activate the intumescent material at multiple locations over a corresponding area of the casing.

Abstract: A fuel spray nozzle includes a fuel circuit having in series a gallery, circumferentially spaced passages arranged in a row around the nozzle, and an annular spin chamber. Each passage has an inlet for receiving a respective portion of the fuel from the gallery and a metering orifice for discharging its portion of the fuel. The passages are configured such that, when the flow of liquid fuel to the inlet port is shut off, a respective differential static pressure develops across stagnant liquid fuel remaining between the inlet and the metering orifice of each passage, and the passages are further configured such that one or more selected passages develop a different differential static pressure to the remaining passages causing a flow of purging air to enter the gallery from the combustor through the selected passages and exit through the remaining passages, thereby purging the gallery and the passages of fuel.

Abstract: Embodiments described herein relate to methods and apparatuses for performing classification of a classification subject.

Abstract: An electrical power system includes: an H-bridge DC:DC power converter including first and second half-bridge circuits having low-side transistors and a high-side transistors, and an inductor connected between AC sides of the first and second half-bridge circuits; a DC power source connected to a first half-bridge circuit DC side; a DC electrical network connected to a second half-bridge circuit DC side; and a control system. The control system: controls the low-side and high-side transistors' switching state of the first and second half-bridge circuits; monitors one or more electrical power system operating parameters and determines whether there is a fault in the DC electrical network; and in response, modifies a switching operation of the low-side and high-side transistors of the first and second half-bridge circuits to supply a controlled amount of current from the DC power source to the DC electrical network.

Abstract: A method of operating a laser additive manufacturing machine includes manufacturing at least one first fluid-flow coupon, that includes a plate defining a plurality of holes, at a corresponding beam offset value of the laser additive manufacturing machine. The method further includes disposing the at least one first fluid-flow coupon in a testing rig, directing a fluid flow towards the at least one first fluid-flow coupon, measuring a fluid flow rate through the at least one first fluid-flow coupon, determining a calibration curve by correlating a beam offset of the laser additive manufacturing machine with a flow parameter based on the fluid flow rate through the at least one first fluid-flow coupon and the corresponding beam offset value, determining a target beam offset value corresponding to a target flow value of the flow parameter, and calibrating and operating the laser additive manufacturing machine using the target beam offset value.

Abstract: The disclosure relates to a battery pack module, for example for use in an electric or hybrid aircraft. Example embodiments include a battery pack module (600) comprising: a plurality of battery cells (6011-n) arranged in a battery cell array (602); an enclosure (604) comprising a plurality of walls surrounding the battery cell array (602); and a vent (605) connected to the enclosure (604) and arranged to provide a fluid flow path between an interior (607) of the enclosure (604) and an external environment (610) upon a pressure differential between the interior (607) of the enclosure (604) and the external environment (610) exceeding a predetermined threshold, wherein the walls of the enclosure (604) are composed of a fire-resistant laminated material comprising a plurality of fabric layers.

Abstract: The disclosure relates to electrical machine condition monitoring by placement of a Fibre Bragg Grating (FBG) in the stator of an electrical machine. Example embodiments include an electrical machine comprising: a stator having a plurality of stator teeth having windings around each tooth; a rotor rotatably mounted within the stator; and an optical fibre mounted to the stator, wherein the optical fibre comprises a Fibre Bragg Grating, FBG, positioned between an adjacent pair of stator teeth and oriented to measure a tangential strain between the pair of stator teeth.

Abstract: A rotary assembly of a pressurized air system for an aircraft with a rotor configured to be mechanically coupled to a spool of a gas turbine engine and a flow modifier with a first section and a second section. The first section defining a plurality of first flow channels configured to receive flow from the rotor. The second section defining a plurality of second flow channels configured to direct flow towards the rotor. The rotary assembly is configured to permit relative movement between the rotor and the flow modifier to move between a turbine configuration in which the rotor is configured to receive air from an external air source to drive the spool to rotate and a compressor configuration in which the rotor is configured to be driven to rotate by the spool and to receive and compress air from the gas turbine engine.

Abstract: A battery pack module, for example, is used in an electric or hybrid aircraft. A battery pack module includes: a plurality of battery cells arranged in a battery cell array; a battery management system electrically connected to the battery cell array; an enclosure surrounding the battery cell array; a vent connected to the enclosure and arranged to provide a fluid flow path between an interior of the enclosure and an external environment; a disc arranged to provide a fluid seal between the interior of the enclosure and the vent, the disc configured to rupture upon a pressure differential between the interior of the enclosure and the external environment exceeding a predetermined threshold; and a sensing circuit connected between the disc and the battery management system and configured to provide a signal to the battery management system upon rupture of the disc.

Abstract: A guide vane assembly includes a guide vane and a sealing assembly slidable along a span of the guide vane relative to the guide vane and extending along a chordal axis and the span of the guide vane. The sealing assembly includes a plate configured to be disposed around at least a portion of an external surface of the guide vane. The sealing assembly further includes a manifold coupled to the plate and configured to receive pressurized fluid therein. The manifold is disposed around the plate. The sealing assembly further includes a plurality of flow tubes extending between the manifold and the plate. Each of the plurality of flow tubes are configured to receive the pressurized fluid from the manifold.

Abstract: A gas turbine engine comprises a fan mounted to rotate about a main longitudinal axis; an engine core, comprising in axial flow series a compressor, a combustor, and a turbine coupled to the compressor through a shaft; a reduction gearbox that receives an input from the shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the shaft; wherein the compressor comprises a first stage at an inlet and a second stage, downstream of the first stage, comprising respectively a first rotor with a row of first blades and a second rotor with a row of second blades, the first and second blades comprising respective leading edges, trailing edges and tips, and wherein the ratio of a maximum leading edge radius of the first blades to a maximum leading edge radius of the second blades is greater than 2.8.

Abstract: Disclosed is a computer-implemented method for controlling an engine system of a vehicle comprising: determining an operating condition of the vehicle; determining one or more contextual conditions relevant to the vehicle; selecting, based upon both the determined operating condition and the determined one or more contextual conditions, a control profile for the engine system from a directory comprising a plurality of control profiles having different control characteristics; applying the selected control profile to a controller of the engine system; and controlling the engine system with the controller in accordance with the selected control profile. Also disclosed are an engine control system, a gas turbine engine, and an aircraft.

Abstract: A gas turbine engine for an aircraft comprising an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor. A fan located upstream of the engine core, the fan comprising a plurality of fan blades and having a fan diameter and a gearbox arranged to receive an input from the core shaft and to output drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, thereby defining a gear ratio. The gearbox being an epicyclic gearbox. A gearbox diameter is defined as the pitch circle diameter of the ring gear; and a geared-fan value defined by a product of the fan diameter and gear ratio, which are divided by the gearbox diameter, being greater than 12.

Abstract: An electrically insulating gas composition comprises C3F7CN, in an amount between 22% and 70% by volume and one or more inert gas selected from the list consisting of nitrogen, carbon dioxide (CO2), air and argon.

Abstract: A butterfly valve for a conduit defining a passage for a flow of a fluid therethrough in a flow direction. The butterfly valve includes a shaft rotatably mounted to the conduit and defining a longitudinal axis along its length. The butterfly valve includes a valve body coupled to the shaft, such that the valve body is rotatable along with the shaft about the longitudinal axis between a closed position and a fully open position. The valve body includes a first major surface, a second major surface opposite to the first major surface, a perimeter surface, a central plane, a first lobe, a second lobe, and a third lobe.

Abstract: A method of operating a gas turbine engine including: an engine core with a turbine, compressor, a fuel combustor, and a core shaft connecting the turbine to the compressor; a fan; a gearbox that receives an input from the core shaft and outputs drive to the fan; an oil loop system arranged to supply oil to the gearbox; and a heat exchange system including: an air-oil heat exchanger through which the oil flows; a fuel-oil heat exchanger through which the oil and the fuel flow; a temperature sensor downstream of the fuel-oil heat exchanger; and a valve arranged to allow oil or air flow rate through at least one heat exchanger to be varied, the method including: determining if the fuel temperature has increased above a set threshold at cruise conditions; and in response, controlling the valve so as to change the flow rate through the heat exchanger.

Abstract: A 3D printed metal coil for an electrical machine. The 3D printed coil has a plurality of turns and is configured to fit within a slot in an electrical machine. A cross-sectional shape of successive turns of the plurality of turns varies such that a portion of each turn forms a part of an external surface of the metal coil, the external surface forming an interface with a side of the slot.

Abstract: A DC:DC converter includes: a DC:AC converter circuit having DC and AC sides; an AC:DC converter circuit having DC and sides; an AC link connecting the AC side of the DC:AC circuit and the AC side of the AC:DC converter circuit, the AC link including a transformer having a first winding connected to the AC side of the DC:AC converter circuit and a second winding connected to the AC side of the AC:DC converter; a capacitor; and a switch arrangement having a first state and a second state, wherein: in the first state, the capacitor is connected in series between the AC side of the DC:AC converter circuit and the first winding of the transformer; and in the second state, there is a current path between the AC side of the DC:AC converter circuit and the first winding of the transformer that does not include the capacitor.