Abstract: A gas turbine engine (10) for an aircraft comprises an engine core (11) comprising a turbine (19), a compressor (14), a core shaft (26), and a core exhaust nozzle (20), the core exhaust nozzle (20) having a core exhaust nozzle pressure ratio calculated using total pressure at the core nozzle exit (56); a fan (23) comprising a plurality of fan blades; and a nacelle (21) surrounding the fan (23) and the engine core (11) and defining a bypass duct (22), the bypass duct (22) comprising a bypass exhaust nozzle (18), the bypass exhaust nozzle (18) having a bypass exhaust nozzle pressure ratio calculated using total pressure at the bypass nozzle exit; wherein a bypass to core ratio of: bypass ? exhaust ? nozzle ? pressure ? ratio core ? exhaust ? nozzle ? pressure ? ratio is configured to be in the range from 1.1 to 2.0 under aircraft cruise conditions.

Abstract: A gas turbine engine for an aircraft and a method of operating a gas turbine engine on an aircraft. Embodiments disclosed include a gas turbine engine for an aircraft including: an engine core has a turbine, a compressor, and a core shaft; a fan located upstream of the engine core, the fan has a plurality of fan blades; a nacelle surrounding the engine core and defining a bypass duct and bypass exhaust nozzle; and a gearbox that receives an input from the core shaft and outputs drive to the fan wherein the gas turbine engine is configured such that a jet velocity ratio of a first jet velocity exiting from the bypass exhaust nozzle to a second jet velocity exiting from an exhaust nozzle of the engine core at idle conditions is greater by a factor of 2 or more than the jet velocity ratio at maximum take-off conditions.

Abstract: An exhaust nozzle for a gas turbine engine comprises an exhaust duct and a first flap. The exhaust duct is configured to receive an exhaust flow of gas from a combustor of the gas turbine engine. The first flap is rotatably coupled to the exhaust duct for rotation about a first axis of rotation. Further, the first flap at least in part defines an exhaust gas passageway configured to convey the exhaust flow of gas to an exterior of the gas turbine engine. Additionally, the first flap comprises a first pin. The exhaust nozzle comprises a first moveable cam having a first moveable slot configured to slidably receive the first pin. The exhaust nozzle is configured such that movement of the first moveable cam causes the first flap to be moved about the first axis of rotation between a first inner position and a first outer position.

Abstract: A power electronics converter connectable, on a DC-side, to a DC electrical network and either, on an AC-side, to an electrical machine coupled to a drive shaft of an engine or propulsor, or, on a second DC-side, to a battery pack. The power electronics converter includes: a power conversion unit including a plurality of semiconductor switching elements and a DC-link; and a gate driver unit, configured to control the semiconductor switching elements so that the power conversion unit: inverts DC power received from the DC electrical network to AC power and provides the AC power to the electrical machine, rectifies AC power received from the electrical machine to DC power and provides the DC power to the DC electrical network, or performs DC-DC conversion between the DC-electrical network and the battery pack; wherein the gate driver unit includes an equipment health monitoring component.

Abstract: A gas turbine engine configured with an engine core. A fan located upstream of the engine core, the fan comprising a plurality of fan blades; 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. The gearbox being an epicyclic gearbox comprising a sun gear, a plurality of planet gears, a ring gear, and a planet carrier on which the planet gears are mounted, the planet carrier having an effective linear torsional stiffness and the gearbox having a gear mesh stiffness between the planet gears and the ring gear. Additionally, the product of the effective linear torsional stiffness of the planet carrier and the gear mesh stiffness between the planet gears and the ring gear is greater than or equal to 5.0×1018 N2m?2.

Abstract: An organic composite gas storage tank 300 comprises a hollow central portion 306 which is substantially cylindrical and formed integrally with first and second end portions 302, 304, and which defines a longitudinal tank axis 301. The first end portion comprises a hollow truncated conical region which meets the hollow central portion at a first end thereof. The hollow central portion comprises first and second hollow truncated conical portions 306A, 306B, the external radius of a given hollow truncated conical portion decreasing in a direction towards a corresponding end portion. The tank comprises an organic composite fibre winding extending between first and second positions along the length of the tank which coincide with the first and second hollow truncated conical portions of the hollow central portion respectively, biassing these portions together and increasing the axial strength of the central portion.

Abstract: A propulsive aircraft gas turbine engine comprises a turbine disposed in a gas turbine engine core flow and a recuperator heat exchanger disposed downstream of the turbine in gas turbine engine core flow, the recuperator heat exchanger being configured to transfer heat from the gas turbine engine core flow to gas turbine engine fuel. The recuperator heat exchanger is configured to accommodate a portion of the gas turbine engine core flow therethrough, the remainder being bypassed around the recuperator heat exchanger.

Abstract: A composite storage tank system for gaseous hydrogen comprises a composite storage tank having composite wall enclosing a gas storage volume, the composite wall including a metal hydride element, or a metal element capable of forming a metal hydride in the presence of hydrogen, the system further comprising measuring apparatus arranged to measure an electrical characteristic of the metal hydride element or the metal element. The history of leakage of gaseous hydrogen from the tank, the current rate of leakage and the physical condition of the composite wall in the vicinity of the metal or metal hydride element may be inferred from a measurement of the electrical characteristic, without taking the tank out of service as is required in the case of known leaks tests such as a vacuum test, helium leak test or hydrogen sniffing test.

Abstract: A method of manufacturing a composite laminate. The method comprises providing a base layer, providing a discontinuous reinforcing patch on the base layer, and providing a top layer over the base layer and discontinuous reinforcing patch. Also, a composite laminate having a discontinuous reinforcing patch interposed between a base layer and a top layer. The discontinuous reinforcing patch comprises a patterned nanomaterial layer with nanomaterial-filled zones and vacant zones.

Abstract: AC-DC converter circuits which may include: first and second rectifier circuits each having a plurality of input connections for connection to respective first and second sets of windings of a generator, each input connection connected between a pair of series-connected rectifier diodes connected between first and second output terminals, an output capacitor connected between the first and second output terminals; a first output diode connected between the second output terminals of the first and second rectifier circuits; and a first output switch connected between the second output terminal of the first rectifier circuit and the first output terminal of the second rectifier circuit.

Abstract: A method of treating an iron-cobalt component is disclosed. The method comprises: heat treating the component using a temperature of at least 700° C.; applying a static magnetic field of at least 3000 A/m to the component during the heat treatment. Also disclosed is a furnace for treating the iron-cobalt component, and a method of forming a stator for a transverse flux electric machine.

Abstract: There is provided a method of manufacturing a component of a gas turbine engine, comprising: providing a precursor component having at least one internal cooling passage configured to receive a flow of cooling air therethrough; estimating a predicted temperature profile for the component based on one or more operating parameters of the gas turbine engine, the predicted temperature profile indicating a predicted operating temperature of at least one gas-washed surface of the component; determining a thermal barrier coating (TBC) configuration for the component based on the predicted temperature profile, comprising setting a TBC thickness to be below a threshold thickness in a region of the at least one gas-washed surface of the component based on the predicted operating temperature of the at least one gas-washed surface of the component exceeding a threshold temperature; and applying a TBC to the precursor component according to the TBC configuration.

Abstract: A temperature measurement system for a gas turbine engine, the gas turbine engine including, in axial flow sequence, a compressor section, a combustor section having plural fuel spray nozzles, and a turbine section. The temperature measurement system includes one or more optical thermometers, each optical thermometer configured to measure the temperature of a component washed by the working gas of the engine, the or each component being in the combustor section or the turbine section at a first position along the axis of the engine.

Abstract: Electrical power systems for distributing electrical power in arrangements including one or more gas turbine engines; one such system includes: one or more rotary electric machines coupled to a gas turbine engine spool; a set of converter circuits connected to the rotary electric machines converting between alternating current (ac) and direct current (dc), wherein the rotary electric machines and the converter circuits output a number R?2 of dc power channels, each channel having an index r=(1, . . . , R); and a group of N dc load channels connected to the R dc power channels by a switching arrangement, wherein N>R and each dc load channel has an index n=(1, . . . , N). For each respective N load channels, a current limiting device (CLD) limits the current flowing from power channels to a load connectable to the electrical power system via the respective load channel.

Abstract: A system for inserting a flexible robotic arm into a workspace, the system having: a feed mechanism having a housing containing a drive mechanism, the drive mechanism gripping the flexible robotic arm using at least one drive wheel which is coupled to a drive motor, the feed mechanism is provided with at least one force sensor; and a haptic controller coupled to the feed mechanism, the haptic controller having input controller for instructing the drive motor within the feed mechanism to activate in response to the signal from the input controller, and wherein the input controller is provided with haptic feedback to provide an operator an indication of the state of operation of the feed mechanism based on signals output from signals provided by the force sensors.

Abstract: A feed mechanism for inserting and/or retracting a flexible robotic arm from an area, the feed mechanism including a housing, a passageway extending about a central longitudinal axis through the length thereof, a drive portion and rotational portion, the drive portion not being fixedly connected within the housing and having at least a pair of drive wheels coupled to a drive motor, the drive wheels are connected to a mounting frame with the mounting frame being connected to pivotable linkages with at least one of the linkages being connected to a spring, such that the expansion or contraction of the spring allows the drive wheels to move relative to the longitudinal axis, and the rotational portion being coupled to a motor, the rotational motor having a gear system that connects to the drive portion and causes a rotation of the drive portion about the central longitudinal axis within the housing.

Abstract: A measurement apparatus for measuring a flow rate of a powder includes a casing, a nozzle configured to dispense the powder, a fixture plate, a weighing scale, and a powder collector. The fixture plate includes a plurality of pinhole members. Each pinhole member includes a tip, a cylindrical hole extending from the tip, and a discharge passage. The cylindrical hole of each pinhole member has a diameter. The diameters of the cylindrical holes of the plurality of pinhole members are different from each other. The nozzle is configured to dispense the powder selectively into the cylindrical hole, and the powder collector is configured to receive at least a portion of the powder from the discharge passage.

Abstract: A fuel system for a gas turbine engine. The fuel system comprises a fuel offtake configured to divert a portion of hydrogen fuel from a main fuel conduit, a burner configured to burn the portion of hydrogen fuel diverted from the main fuel conduit and at least first and second heat exchangers. The first heat exchanger is configured to transfer heat from exhaust gasses produced by the burner to hydrogen fuel in the main fuel conduit and the second heat exchanger is provided upstream in hydrogen flow of the first heat exchanger and is configured to transfer heat from a further heat exchange fluid to hydrogen fuel in the main fuel conduit. In an embodiment, the further heat exchange fluid is compressor bleed air bled from a core compressor of the gas turbine engine.

Abstract: A fluid control valve is disclosed, comprising: a valve body defining an outer wall for a curved flow path through the fluid control valve; and a valve element defining an opposing inner wall and rotatable relative to the valve body about a pivot point through between a closed position a range of open positions. A separation between the first inner wall and the outer wall along a restrictor portion of the flow path varies between open positions. The first inner wall and the outer wall are cooperatively defined so that for at least some open positions the separation between the first inner wall and the outer wall is constant along the respective restrictor portion of the flow path.

Abstract: A system for inspecting a complex component, the system comprising: a flexible inspection device having a driver for controlling the motion of the flexible inspection device by manipulating the relative positions of a plurality of joints within the device, the flexible device having a sensor on its distal end; a feed mechanism for controlling the insertion or retraction of the flexible device into or from the complex component; a component driver for driving the movement of an aspect of the complex component from at least a first position to a second position; and a computer running a computer program, the computer interfacing with the flexible inspection device, the feed mechanism, and the component driver, so as to link the operation of the flexible inspection device, the feed mechanism and the component driver through a single program.