Abstract: A gas turbine engine includes: a fan rotating about an engine main axis; a core duct; an engine core; an Engine Section Stator (ESS) including a plurality of ESS vanes and arranged in the core duct downstream of the fan; and a plurality of variable inlet guide vanes (VIGV) adapted to rotate about a pivot axis and arranged in the core duct downstream of the ESS. The VIGV vanes are arranged angularly rotated with respect to the ESS vanes such that the VIGVs are shielded by the ESS, thereby protecting the VIGVs from icing and from ice shedding from the ESS vanes.

Abstract: A gas turbine engine including a fuel delivery system arranged to provide fuel; a combustor arranged to combust at least a proportion of the fuel; a primary fuel-oil heat exchanger arranged to have up to 100% of the fuel provided by the fuel delivery system flow therethrough; and a secondary fuel-oil heat exchanger arranged to have a proportion of the fuel from the primary fuel-oil heat exchanger flow therethrough. Fuel is arranged to flow from the primary fuel-oil heat exchanger to the secondary fuel-oil heat exchanger whereas oil is arranged to flow from the secondary fuel-oil heat exchanger to the primary fuel-oil heat exchanger. The method includes using at least one of the primary fuel-oil heat exchanger and the secondary fuel-oil heat exchanger to heat the fuel so as to adjust the fuel viscosity to a maximum of 0.58 mm2/s on entry to the combustor at cruise conditions.

Abstract: An aircraft turbofan gas turbine engine includes a fan assembly, a compressor module, and a turbine module. An electric machine is positioned downstream of the fan assembly and is connected to the turbine module. The fan assembly includes a highest pressure fan stage having a plurality of fan blades defining a fan diameter. The turbine module includes a lowest pressure turbine stage having a row of rotor blades. The gas turbine engine has a fan tip axis that joins a radially outer tip of the leading edge of one of the plurality of fan blades of the highest pressure fan stage, and the radially outer tip of the trailing edge of one of the rotor blades of the lowest pressure turbine stage. The fan tip axis lies in a longitudinal plane which contains a centreline of the gas turbine engine. The fan axis angle is between 11 and 20 degrees.

Abstract: A fluid atomizer and methods of atomizing fluids are disclosed. The fluid atomizer may comprise an inner member and one or more outer members. The inner member defines an interior conduit for providing a first-fluid flowpath from a supply end of the atomizer to a discharge end of the atomizer along a central axis. The one or more outer members are positioned radially outward of the inner member from the central axis. The inner and outer members define a second-fluid flowpath extending from a second-fluid supply conduit to a second-fluid discharge plenum. The second-fluid flowpath comprises a tangential conduit spiraling along the axis from the second-fluid supply conduit to a terminal end; an annulus downstream from and in fluid communication with the tangential conduit; and a second-fluid discharge plenum downstream from and in fluid communication with the annulus.

Abstract: A system for finishing a surface of a workpiece. The system includes a laser unit configured to emit a laser radiation. The system further includes an attenuator disposed within the laser unit and configured to adjust optical parameters of the laser radiation. The system further includes a cavitation chamber storing a liquid medium. The workpiece is mounted within the cavitation chamber and is in contact with the liquid medium. The system further includes at least one lens configured to focus at least a portion of the laser radiation and transmit at least one laser beam towards the workpiece.

Abstract: A method of mitigating contrails produced by an aircraft having a set of gas turbine engines, comprises the steps of (i) for each engine in a first subset of the engines, reducing the operating efficiency of the engine to produce a reduction in thrust provided by that engine and (ii) for each engine in a second subset, increasing the fuel flow to the engine to increase the thrust provided by that engine, the set of at least two gas turbine engines consisting of the first and second subsets. The method provides for contrail mitigation action by means of engine operating efficiency reduction to be directed to a first subset of engines for which contrail mitigation per unit engine operating efficiency reduction is greatest, the resulting reduction in thrust provided by such engines being at least partially compensated by increasing fuel flow to engines of the second subset.

Abstract: Monitoring circuitry connectable to power conversion circuitry enclosed within packaging, the power conversion circuitry including terminals providing external connections to nodes of the power conversion circuitry enclosed within the packaging, the monitoring circuitry including: a comparator including a first input terminals connectable to first and second terminals of the power conversion circuitry and a second input terminal connected to a reference voltage, wherein the first and second terminals provide external connections to first and second nodes connected along respective current paths each connected to switching circuitry of the power conversion circuitry enclosed within the packaging, wherein the comparator detects a switch state of the switching circuitry based on a voltage generated at the first input terminal and the reference voltage; processing circuitry connected to the comparator and configured to monitor the power conversion circuitry based on the detected switch state and a signal of the p

Abstract: A collision avoidance method for a water-based vessel, including: obtaining real time data relating to the path of two or more vessels; identifying a collision risk between the two or more vessels; determining if the collision risk is above a predetermined threshold, wherein when the collision risk is above the predetermined threshold, determining one or more collision avoidance manoeuvres on the basis of historical navigational data which corresponds to the real-time data; providing the one or more collision avoidance manoeuvres to an operator of the one or more vessels.

Abstract: A cabin blower for an aircraft, the system comprising: a cabin blower compressor; an electric machine; and a controller configured to control the cabin blower system so that: in a cabin blower mode of operation, the cabin blower compressor is driven by power extracted from one or more spools of a gas turbine engine of the aircraft and provides a flow of air to a cabin of the aircraft. The controller may be further configured to control the system so that: in a rotor bow mitigation mode of operation, the cabin blower compressor is driven by the electric machine using electrical power from an electrical power source and provides a flow of air through a core of the gas turbine engine to remove heat from the core. A method of operating a cabin blower system of an aircraft is also provided.

Abstract: An inlet assembly includes a web extending between a first end and a second end along a first axis. The web includes first and second major surfaces. The inlet assembly includes a load transfer flange at least partially disposed around the web and configured to be fixedly coupled to a gas turbine engine. The inlet assembly includes first vanes spaced apart from each other at least along the first axis. Each first vane extends between the first major surface of the web and the load transfer flange. The inlet assembly includes second vanes spaced apart from each other at least along the first axis. Each second vane extends between the second major surface of the web and the load transfer flange.

Abstract: An electrical machine with a rotor coupled to a drive shaft of an engine; a DC electrical network; a power electronics converter connected, on a DC-side, to the DC electrical network, and, on an AC-side, to the electrical machine, the power electronics converter comprising a plurality of transistors and associated diodes connected in anti-parallel with the transistors; and a controller configured to control switching of the transistors so that the converter either inverts DC power to AC power or rectifies AC power to DC power. The controller is further configured, responsive to a determination that there is a fault in the DC electrical network, to operate in a fault mode in which the controller controls the switching of the transistors so that a fault current is shared between the transistors and the associated diodes.

Abstract: Multi-engine aircraft power and propulsion systems and methods of restarting an engine of a multi-engine aircraft during fight are provided. One such method comprises: determining a condition to the effect that a flame in the combustion equipment of the second gas turbine engine has been extinguished; responsive to the determination, supplying electrical power from the electrical energy storage system to one or more of the electric machines of the second gas turbine engine and operating said one or more electric machines as motors to limit a reduction in a speed of the one or more spools of the second gas turbine engine following extinguishment of the flame in its combustion equipment; and restarting the second gas turbine engine by relighting the combustion equipment of the second gas turbine engine.

Abstract: An aircraft comprises a hydrogen-fuelled propulsion system, a plurality of like generally cylindrical hydrogen storage tanks and a conveying system arranged to convey hydrogen from the hydrogen storage tanks to the hydrogen-fuelled propulsion system. The aircraft further comprises a fuselage having a cargo bay (502) including one or more (510A-G) of the plurality of hydrogen storage tanks, the longitudinal axes (511A-G) of the one or more hydrogen storage tanks within the cargo bay extending parallel to the longitudinal axis (501) of the fuselage and lying in one or more planes (595, 597) extending across the width dimension of the cargo bay. The hydrogen storage tanks within the cargo bay have a common aspect ratio R in the range 4.2?R?25.7, allowing the volume of space with the cargo bay occupied by stored hydrogen to be maximised or approximately maximised.

Abstract: A method of manufacturing a rotary abrasive machining tool, the rotary abrasive machining tool including a hub and a plurality of abrasive segments mounted to the hub, the method including the steps of: mounting each abrasive segment on the hub; machining an abrading edge on each abrasive segment while the abrasive segment is mounted on the hub.

Abstract: A method of determining performance characteristics of a flow machine having a rotor interacting with a flow field. The method comprises: receiving performance data for the flow machine comprising data values of a performance parameter of the rotor and mass flow for the flow machine at one or more defined rotor condition, the performance data defining a two-dimensional array of data in which points for a common rotor condition are identifiable; determining or receiving exit mass flow values for the flow downstream of the rotor; and identifying one or more point in the received performance data and interpolating from said one or more point to a corresponding one or more point at a different rotor condition based on a correlation of the exit mass flow values for said points.

Abstract: Disclosed is a method of manufacturing a component, the method comprising: determining a predicted direction and extent of distortion of a portion of the component; designing a support structure based on the predicted direction and extent of distortion of the portion of the component; additive manufacturing, by melting and fusing powder from a build plate, the component and the support structure. The support structure comprises, a hook structure comprising an elongate arm and a hook protruding from the elongate arm. The hook is deposited to abut a distortion surface of the component to restrain distortion of the component. The distortion surface is the furthest in the direction of distortion of the component. The elongate arm is deposited to extend from the hook in a direction having a vector component opposing the direction of distortion such that shrinkage of the elongate arm provides a force to minimise distortion of the component.

Abstract: A combustor assembly for gas turbine engine, combustor assembly including: combustor wall including interior surface and combustor wall opening, wherein interior surface partially defines combustion chamber, wherein combustor wall opening extends between combustion chamber and its exterior; sealing element disposed partially within combustor wall opening and includes air inlet, air outlet and air passageway, wherein air outlet exits into combustion chamber and delivers flow of air received from exterior of combustion chamber via air inlet and air passageway to combustion chamber; and fuel nozzle coupled to sealing element and configured to deliver fuel into combustion chamber, wherein combustor wall further includes first bearing surface and sealing element further includes second bearing surface, wherein first bearing surface is concave and forms part of first spherical surface such that first and second bearing surfaces are configured to move relative to each other about central point of first spherical sur

Abstract: An electrical-discharge machining tool comprising a ground electrode, a moveable and activatable assistive electrode and a cutting electrode, a first conduit for supplying a dielectric and a second conduit for flushing dielectric material, wherein when used on a dielectric layer on a substrate the assistive electrode is activated and positioned substantially between the ground electrode and the cutting electrode.

Abstract: A fuel precursor is provided for producing hydrogen fuel by reacting aluminium and water. The fuel precursor has aluminium particles suspended in a hydrophobic liquid such that when the fuel precursor is introduced to water, the suspended aluminium particles migrate to the water and react therewith to produce hydrogen. The suspended aluminium particles are non-spherical, angular particles.

Abstract: There is disclosed a method of manufacturing a component. The method comprises melting and fusing powder in layers from a build plate to form the component and a disposable support structure, heat treating the component; and removing the support structure. Each layer of the support structure and the component are formed such that there is at least a 10-micron gap between them, to ensure that the component and the support structure are not fused together.