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 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: 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: An aircraft propulsion system comprises a propulsor an electric motor coupled to the propulsor. The electric motor comprises a surface mounted permanent magnet electric machine comprising a rotor mounted radially inward of a stator. A Motor Diameter Ratio (MDR) is defined as an inner diameter (Dstator,in) of the motor stator in metres divided by an outer diameter (Dstator,out) of the motor stator in metres. The MDR of the electric motor stator is within 10% of the value given by the equation: MDR = 0.83 × ( Torq ? u ? e L a ? c ? t ? i ? v ? e × 1 U fan , tip ) 0 . 0 ? 8 where: T is the maximum torque rating of the electric motor in kilonewton metres; Lactive is the active length of the motor stator in metres; and Utip is the tip speed of the propulsor at the maximum rated torque of the electric motor in metres per second. In the described embodiments, the MDR is less than 1.

Abstract: A battery charging system including a battery enclosure defining an interior space containing a battery storage medium, the interior space configured to house one or more battery cells; a charging terminal electrically coupled to the one or more battery cells and configured to receive electrical power from a power source to charge one or more battery cells; wherein the interior space is configured to be coupled to a pressurising device for applying pressure to the battery storage medium in the interior space; and wherein during charging of the one or more battery cells, the battery storage medium in the interior space is pressurised to cause an isostatic pressure to be applied to the one or more battery cells. A method of charging of charging one or more battery cells provided.

Abstract: There is provided an air pressurisation system comprising: a blower compressor coupled to a spool of a gas turbine engine and configured to receive inlet air from a bypass duct of the gas turbine engine; an air treatment apparatus to mix air from the air cycle line with air from the bypass line to control a temperature of air for discharge to an airframe system; and a core bleed line configured to provide a second inlet flow of air from a compressor of the gas turbine engine to the air treatment apparatus in an augmented air supply mode of the air pressurisation system; wherein the core bleed line is configured to provide the second inlet flow of air directly to the bypass line or mix the second inlet flow of air with air from the blower compressor upstream of the bypass line.

Abstract: Engine Control and Monitoring Systems (ECaMS) for engines are disclosed. An ECaMS comprises a first processor node and a second processor node. The first processor node comprises a first acquisition integrated circuit (IC), a first output IC, and a first processor. The second processor node comprises a second acquisition IC, a second output IC, and a second processor. The first acquisition IC is connected directly to the second acquisition IC.

Abstract: Synchronisation methods for synchronising processor nodes of an Engine Control and Monitoring System (ECaMS) for an engine. A method comprises counting, at a first acquisition integrated circuit in a first processor node of the ECaMS, a first control cycle count, and storing at the first acquisition integrated circuit a first transmission slot index. The method further comprises counting a second control cycle count and storing a second transmission slot index at a second acquisition integrated circuit in a second processor node of the ECaMS. The method also comprises transmitting a message including the first control cycle count and transmission slot index from the first to second acquisition integrated circuits, and receiving the message at the second acquisition circuit. The method also comprises synchronising the first and second processor nodes using the first and second control cycle counts and transmission slot indexes.

Abstract: Methods for modifying an Engine Control and Monitoring System (ECaMS) for an engine. A method comprises identifying a provisioning deficit in the ECaMS, wherein the ECaMS comprises a first processor node and a second processor node. The first processor node comprises a first acquisition integrated circuit (IC), a first output IC, and a first processor. The second processor node comprises a second acquisition IC, a second output IC, and a second processor. The first acquisition IC is connected directly to the second acquisition IC. The method comprises connecting an expansion unit to the ECaMS. The expansion unit comprises one or more expansion unit ICs, said one or more expansion unit ICs being connected to one or more ICs of the ECaMS.

Abstract: A gas turbine engine includes an engine core including a compressor, a combustor, and a turbine, the compressor being connected to the turbines through a respective shaft; and a cabin blower system comprising: an electric variator comprising a first electrical machine connected to a first shaft arranged along a first axis, a second electrical machine connected to a second shaft arranged along a second axis, and a power management system; a cabin blower comprising a compressor driven by a third shaft arranged along a third axis, the compressor comprising an air inlet and an air outlet; and a differential gearbox. The gas turbine engine further includes an accessory gearbox arranged within an accessory gearbox casing and adapted to drive the cabin blower system.

Abstract: The present disclosure relates to an electric drive apparatus 201, 202 comprising an inverter system 220, an electric motor 230 and a controller 290. The electric motor 230 includes a rotor 234 and a plurality of phase windings 221, 222, 223, 224. The inverter system 220 is configured to provide a respective current waveform 321, 322, 323, 324 to each of the phase windings 221, 222, 223, 224 of the electric motor 230. Each current waveform 321, 322, 323, 324 is defined by a group of electrical characteristics including: a frequency composition, a phase shift relative to a reference waveform 349, and an amplitude. For one or more of the current waveforms 321, 322, 323, 324, the controller 290 is configured to control one or more of the group of electrical characteristics to cause a periodically varying torque to be applied to the rotor 234.

Abstract: An aircraft propulsion system fuel system comprises a fuel line configured to receive liquid hydrogen fuel from a fuel tank, a vaporizer configured to vaporize liquid hydrogen fuel from the fuel line to generate a supercritical or gaseous fuel, a main fuel pump configured to receive and to pump the gaseous or supercritical fuel from the vaporizer during operation of the propulsion system, and a heater provided downstream in fuel flow to the main fuel pump, and configured to raise the temperature of the gaseous or supercritical fuel to a propulsion system delivery temperature.

Abstract: A spline cleaning device for cleaning splines formed within a component of a gas turbine engine. The spline cleaning device comprises: a central support; a central support sleeve that surrounds and is movable with respect to the central support; a scraper having protrusions that substantially correspond to the splines, the scraper being attachable to the central support sleeve, and configured to remove surface contaminants from the surface of the splines; and a collector sump that is attachable to the central support and configured to collect the surface contaminants that have been removed from the surface of the splines.

Abstract: A method of forming a protective coating. The method includes providing a substrate including at least one chemical element and a surface; forming a basecoat composition including an aluminium phase including aluminium; applying the basecoat composition on the surface of the substrate to form a basecoat layer; heating the basecoat layer to a first temperature for a predetermined period of time; applying a glow discharge plasma on the basecoat layer; and heating the basecoat layer to a second temperature greater than the first temperature, in order to activate an exothermic reaction between at least the aluminium phase of the basecoat layer and the at least one chemical element of the substrate, wherein the exothermic reaction forms the protective coating on the surface of the substrate.

Abstract: There is disclosed a gas turbine engine comprising: an electrically-powered motor configured to rotate a driven spool of the gas turbine engine; a primary controller configured to conduct a primary function using the motor; and a bow controller configured to selectively control the motor to perform a rotor bow mitigation operation in which the motor drives the driven spool to rotate to mitigate a non-uniform thermal distribution in a rotor of a spool of the gas turbine engine.

Abstract: Disclosed is a fuel system for a gas turbine engine. The system comprises a fuel pump for fluid communication with a fuel reservoir; a driving turbine for driving the fuel pump; and a source of compressed air flow to drive the driving turbine. The source of compressed air may be the engine core, a dedicated fuel system compressor or the compressor of a cabin blower system.

Abstract: There is provided a method of starting a gas turbine engine, comprising: selecting a baseline starting procedure of the gas turbine engine based on environmental data; receiving condition information for the gas turbine engine and/or for a starting system of the gas turbine engine, the condition information comprising at least one of: health information for the gas turbine engine and/or the starting system; maintenance information for the gas turbine engine and/or the starting system; and operation information relating to an expected future usage of the gas turbine engine. The method further comprises determining a predicted degradation profile for the gas turbine engine and/or the starting system based on the condition information; determining a starting procedure of the gas turbine engine by adapting the baseline starting procedure based on the predicted degradation profile; and controlling the gas turbine engine and/or the starting system according to the determined starting procedure.

Abstract: Gas turbine engine for aircraft includes: an engine core including a turbine, compressor, and core shaft connecting the turbine to the compressor; a fan located upstream of the core; a gearbox; and a gearbox support arranged to at least partially support the gearbox. The fan has a mass in a range of 150 kg to 1200 kg. A moment of inertia of the fan is greater than or equal to 7.40×107 kgmm2. A radial bending stiffness to moment of inertia ratio of: the ? radial ? bending ? stiffness ? of ? at ? least ? one ? of the ? fan ? shaft ? at ? the ? output ? of ? the ? gearbox and ? the ? gearbox ? support the ? moment ? of ? inertia ? of ? the ? fan may be greater than or equal to 2.5×10?2 Nkg?1 m?1 mm?2.