Abstract: A component including a first flange located in a first section of the component, the first flange including a contact surface. The component also including a second flange located in a second section of the component. The first flange is configured to attach to the second flange, and the second flange includes a contact surface configured to contact the contact surface of the first flange. The contact surface of the first flange and the contact surface of the second flange each has an undulating surface profile, where each undulating surface profile is defined by at least one peak point and at least one trough point connected by a curved line extending in at least one of a radial or a circumferential direction relative to a central axis of the component.

Abstract: An alternating current type electric propulsion system is described that includes an AC generator and a plurality of propulsors electrically coupled to the AC generator. A first propulsor from the plurality of propulsors includes a first motor that drives a first fan of the first propulsor at a first speed. A second propulsor from the plurality of propulsors comprises a second motor that drives a second fan of the second propulsor at a second speed that is different than the first speed.

Abstract: A turbine blade includes a labyrinth of internal channels for the circulation of coolant received through an inlet formed in a terminal portion of the blade root and leading to a duct-defined wall. A first passage intersects the duct and extends through the blade towards a tip. An end of the first passage is arranged to capture incoming coolant flow. A second passage intersects the duct at a position downstream of the first passage intersection. The duct and/or the passage intersections are configured to create a pressure drop in the duct in the direction from the inlet to the second passage intersection. In an axial direction, a duct wall terminates at a position between the inlet and the second passage intersection.

Abstract: Determining magnitude of a field variable of an energy wave through domain of interest, including steps of: defining plurality of master-particles spaced within domain, master-particles being representative of field variables of energy wave at location of respective master-particle, and defining supporting domain ?m for each master-particle; computing field variables including position, magnitude and direction of propagation of each master-particle at predetermined time; defining plurality of virtual-particles within domain representative of magnitude of field variable of wave at location of respective virtual-particle; calculating magnitude uv of field variable of each virtual-particle at time of interest by applying formula: u v = ? m = 1 N ? ? u m ? f ? ( q ? ? 1 ) × g ? ( q ? ? 2 ) Where ? ? v ? ? ? m where N is total number of master-particles, um is magnitude of respective master-particle, f(q1) is an envelope function relating magnitude of virtua

Abstract: A doctor device configured for use in recoating in an operating additive layer manufacturing apparatus. The doctor device includes at least one blade having a first surface and a second surface. The at least one blade is configured to move in a first direction and a second direction, which is opposite to the first direction. The first surface is configured to bend in the second direction upon the at least one blade moving in the first direction and contacting a surface of an additive layer, and the second surface is configured to be rigid upon the at least one blade moving in the second direction and contacting the surface of an additive layer, such that the at least one blade does not bend.

Abstract: A planetary gear box assembly, comprises a sun gear and a plurality of planet gears in meshing engagement with the sun gear; the planet gears in meshing engagement with a ring gear which encircles the plurality of planet gears, each planet gear mounted for rotation in a planet carrier by means of a bearing pin wherein a bore in the planet carrier for receiving the bearing pin is parallel. The bearing pin includes a small axially tapered section adjacent one or both ends and the assembly further comprises a tapered sleeve configured to interference fit between a radially inner wall surface of the parallel bore and a radially outer surface of the or each axially tapered section.

Abstract: DC-AC converter and a method of performing the same. The converter has a DC-DC stage, a DC-AC stage, a positive rail and a negative rail which extend in parallel from the DC-DC stage to the DC-AC stage; and a controller, which is operable to control the DC-DC stage. The DC-DC stage has a first DC-DC stage switch, inductor, and second DC-DC stage switch connected in series in that order, and a zero rail extending in parallel to the positive rail and the negative rail. The DC-AC stage has a plurality of DC-AC stage switches connected between the positive rail and the negative rail and operable to produce the one or more phases of AC power at the output of the DC-AC stage. The DC-AC converter further comprises a neutral rail connected to the DC-DC stage zero rail and provides reference voltage for the one or more phases of AC power.

Abstract: There is disclosed a method and apparatus for finishing an internal channel of a component. The method comprises installing the component in a flow circuit which is configured to drive a fluid flow through the internal channel and controlling the fluid flow through the internal channel so that cavitation bubbles are continuously generated by a hydrodynamic effect to erode the internal channel by implosion of the cavitation bubbles. The fluid flow may comprise abrasive media which may abrade the internal channel.

Abstract: A tank assembly (100) for a gas turbine engine is provided comprising a tank (102) and a plurality of restraints (112, 114). The restraints (112, 114) include a fixing part (124) for securing the tank (102) to a support structure (104). A first restraint (112) has a first rigidity in the direction of a length of the tank (102) and at least one second restraint (114) has a second rigidity in the direction of the length of the tank (102). Upon thermal expansion or contraction of the tank (102) relative to the support structure (104), the or each second restraint (114) flexes to a greater extent than the first restraint (112).

Abstract: A method of manufacture comprising: controlling provision of a first mould part including an inner surface defining a first cavity, the inner surface of the first mould part comprising a plurality of first grooves; controlling provision of a second mould part including an inner surface defining a second cavity, the inner surface of the second mould part comprising a plurality of second grooves; controlling coupling of the first mould part and the second mould part, the first cavity and the second cavity forming a third cavity, the plurality of first grooves and the plurality of second grooves forming a double helical pattern; controlling provision of a powder to the third cavity; and controlling cold isostatic pressing of the powder within the third cavity to form a double helical gear.

Abstract: There are disclosed corresponding methods, systems, controllers (26) and software for machine (10) sensor network management. Upon receiving from a node a request to join an existing network of machine sensors (25), sound waves are emitted in the vicinity of the machine (10). The emitted sound waves are sensed by the node and a corresponding signal output is generated by the node. The signal output from the node is compared with the emitted sound waves and/or a further signal output from one or more machine sensor (25) in the existing network. The node request to join the existing network is authenticated or rejected based on the comparison.

Abstract: A superconducting fault current limiter (10) is shown. It comprises a cryostatic cooling system (20) for containing a cooling medium (26), a superconducting wire (30) immersed in the cooling medium (26) and configured to carry a current, the superconducting wire (30) becoming non-superconducting above a critical current density, and a plurality of heat dissipation elements spaced along and projecting from the superconducting wire (30), wherein the heat dissipation elements have an electrically insulating coating, and whereby the heat dissipation elements transfer heat from the superconducting wire (30) into the cooling medium (26).

Abstract: A gas turbine engine comprising a planetary gear train, and a core engine casing. The gear train has a ratio of greater than approximately 3.0, with an input to the gear train being operatively connected to the compressor section, and an output from the gear train being operatively connected to the fan. The core engine casing encloses the compressor section and the turbine section. The fan has a diameter F, and the core engine casing has a diameter C. The core engine casing diameter C varies along an axial length of the core engine casing, and a ratio (C/F) of the core engine casing diameter C to the fan diameter F is within the range 0.2<(C/F)<0.4, along an axial length of the core engine casing.

Abstract: A spline joint comprising: a sidewall extending along and around an axis defining an axial direction of the joint, wherein the sidewall defines a passage extending from a first end to a second end; wherein the passage is arranged to receive an end of a shaft at the first end; and wherein an engagement portion of an inner surface of the sidewall adjacent the first end is arranged to engage a shaft received in the passage, to transmit torque to the shaft; a base wall extending across the passage and axially spaced from the first end of the passage; an opening formed through the base wall; and an inner wall extending around the opening and in the axial direction from the base wall, such that an annular trough arranged to retain lubricant for the spline joint is defined between the sidewall and the inner wall.

Abstract: A method of manufacturing a fan blade for a gas turbine engine. The method includes providing a compression mould having an internal mould surface corresponding to an outer profile of a fan blade, providing opposing first and second laminates to form a shell corresponding to the mould surface, each laminate comprising a lay-up of plies of fibre reinforcement material, applying a core material comprising quasi-isotropic short fibre reinforced resin in the compression mould so that with the compression mould in a moulding configuration the core material is enclosed by the shell, the core material and the shell forming a pre-form for the fan blade, applying pressure to compress the pre-form so that it conforms to the mould surface, and applying heat to cure the pre-form.

Abstract: Maraging steel alloys are disclosed. The alloys are produced by microalloying of the maraging steel alloy to form carbides at prior austenite grain boundaries to increase Zener drag. A particular example alloy consists essentially of, by weight, 7.4 to 8.4 percent nickel, 7.6 to 8.6 percent chromium, 8.4 to 9.4 percent cobalt, 1.8 to 2.2 percent molybdenum, 2 to 2.6 percent tungsten, 1.6 to 2 percent aluminium, 0.05 to 0.08 percent carbon, a carbide former selected from the group consisting of: niobium at a concentration of 0.25 to 0.28 percent; titanium, at a concentration of 0.2 to 0.28 percent; and vanadium, at a concentration of 0.21 to 0.4 percent; the balance being iron and incidental impurities.

Abstract: A component for a gas turbine engine, comprising: first and second walls; a coolant channel defined by the space between the first and second walls; and a plurality of ribs extending between the first and second walls, subdividing the coolant channel and configured such that the spaces between the ribs define the direction of flow of coolant through the coolant channel; wherein the ribs are arranged in first and second groups; and the second group of ribs is arranged downstream of the first group of ribs in the direction of the flow of coolant such that the ribs of the second group are aligned with the spaces between the ribs of the first group.

Abstract: A turbine arrangement for gas turbine engine, the arrangement comprising a high pressure turbine mounted on a high pressure shaft and a low pressure turbine mounted on a low pressure shaft, wherein the high pressure turbine comprises a single stage turbine rotor configured to rotate in a first direction, and wherein the low pressure turbine comprises three or more rotors (19a, b, c) configured to rotate in a second direction opposite to the first direction. The low pressure turbine is closely coupled to the high pressure turbine with no stator vanes provided between the two.

Abstract: A combined refrigeration and power plant. The power plant comprises an internal combustion engine an air cycle machine refrigerator driven by the internal combustion engine and configured to refrigerate atmospheric air to provide working fluid to combined refrigeration and power generation cycle, a refrigerated air storage unit configured to store working fluid produced by the air cycle machine refrigerator; and first and second heat exchangers. The first heat exchanger arrangement is configured to exchange heat between a device to be cooled and the working fluid, and the second heat exchanger arrangement is configured to exchange heat between the working fluid downstream of the first heat exchanger in the combined refrigeration and power generation cycle and waste heat from the internal combustion engine; and a generator turbine configured to receive heated working fluid from the second heat exchanger arrangement, and configured to power an electrical generator.

Abstract: A de-oiler for separating oil from an air/oil mixture comprises a housing, and a rotatable porous element accommodated within the housing. The housing has a first axial face and a second, opposite, axial face, the first axial face being separated from the second axial face by an axial length. The housing has an inlet positioned on the first axial face, a first outlet positioned on the second axial face, and a second outlet positioned on a radially outwardly facing surface. In use, the inlet is adapted to receive a first flow comprising an air/oil mixture, and rotation of the porous element separates the oil from the air/oil mixture, with the first outlet being adapted to exhaust a second flow comprising de-oiled air, and the second outlet being adapted to exhaust a third flow comprising separated oil.