Abstract: A method of controlling a permanent magnet synchronous electric machine (PMSM) drive using a Deadbeat Predictive Current Control (DBPCC) scheme is provided. The method comprises: determining d-axis and q-axis stator current values (id, iq) representative of a measured PMSM current; determining d-axis and q-axis reference current values (id*, iq*); based on the stator current values (id, iq) and the reference current values (id*, iq*), determining d-axis and q-axis current correction values (Cd, Cq); determining corrected reference current values (id**, iq**) as a sum of the reference current values (id*, iq*) and the current correction values (Cd, Cq); and controlling the PMSM drive using the corrected reference current values (id**, iq**) as reference current inputs of the DBPCC scheme. A controller for performing the method; a system comprising the controller, a PMSM and associated power electronics; and a computer program for performing the method are also provided.

Abstract: A computer-implemented method comprising: controlling input of data quantifying damage received by a compressor of a gas turbine engine into a first machine learning algorithm; receiving data quantifying a first operating parameter of the compressor as an output of the first machine learning algorithm; and determining operability of the compressor by comparing the received data quantifying the first operating parameter of the compressor with a threshold.

Abstract: A fairing for a power generation machine, the fairing comprising: a first layer comprising a metallic material; a second layer comprising a composite; and a third layer positioned between the first layer and the second layer, the third layer being configured to attenuate acoustic waves over a predetermined frequency range.

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 VTOL aircraft has fixed wings and a rotor blade system for providing lift in active and passive modes thereof. Operation of the rotor blade system may be switched between the active mode in which the rotor blade system is driven by a power system of the aircraft and the passive mode in which the rotor blade system is not driven by the power system, the rotor blade system being configurable to provide lift in the passive mode during forward flight of the aircraft. The rotor blade system provides lift in the passive mode, allowing the fixed wings to be shorter than in the case where the rotor system provides lift during vertical take-off and landing but otherwise has no function, thus providing aircraft which is lighter, more compact and more efficient than similar aircraft of the prior art.

Abstract: A gas turbine engine for an aircraft configured with an engine core that has a turbine, a compressor, and a core shaft connecting the turbine to the compressor. A fan located upstream of the engine core, that has a plurality of fan blades. A gearbox arranged to receive an input from the core shaft and to output to the fan so as to drive the fan at a lower rotational speed than the core shaft. The gearbox being an epicyclic gearbox having a sun gear, a plurality of planet gears, a ring gear, and a planet carrier on which the planet gears are mounted. The gearbox having an overall gear mesh stiffness, and wherein the overall gear mesh stiffness of the gearbox is greater than or equal to 1.05×109 N/m and less than or equal to 8.0×109 N/m.

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: The present disclosure relates to a geared gas turbine engine for an aircraft. Example embodiments include a gas turbine engine for an aircraft including: an engine core having a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan having a plurality of fan blades; and a gearbox that receives an input from the core shaft to drive the fan at a lower rotational speed than the core shaft, the gearbox having a gear ratio of around 3.4 or higher, wherein the gas turbine engine is configured such that a jet velocity ratio between a first jet velocity exiting from a bypass duct of the engine and a second jet velocity exiting from an exhaust nozzle of the engine core is within a range from around 0.75 to around 0.82.

Abstract: A propulsor (101) for an aircraft is shown. The propulsor comprises a propulsive fan (106), and an electric machine (108) configured to drive the propulsive fan. The electric machine has a casing containing electrical and electromechanical components, a shaft which extends outside of the casing and which is connected to the propulsive fan, and a seal to seal the casing around the shaft. A depressurisation system depressurises the casing below an external pressure to prevent electrical breakdown within gas in the casing of the electric machine.

Abstract: A nacelle for a gas turbine engine having a longitudinal centre line. The nacelle includes an air intake disposed at an upstream end of the nacelle. The air intake includes, in flow series, an intake lip, a throat and a diffuser. The nacelle further includes a protrusion extending radially inward from the air intake downstream of the intake lip. The protrusion extends circumferentially by a protrusion angle (?p) with respect to the longitudinal centre line of the gas turbine engine.

Abstract: An oil pipe assembly for a gas turbine engine. The oil pipe assembly includes a first pipe that defines a first fluid passage between an oil supply and a bearing chamber, and a second pipe that houses the first pipe and defines a second fluid passage between the first pipe and the second pipe that is supplied with cooling air. The oil pipe assembly also includes a restrictor that extends from the second pipe and restricts the passage of fluid from the second fluid passage before it flows into a breather. Pressure and temperature sensors) are located adjacent the restrictor to detect and measure changes in air pressure and air temperature adjacent the restrictor from which a controller identifies whether a leak has occurred in the first pipe or the second pipe. A method for detecting a leak in the oil pipe assembly, and a gas turbine are also described.

Abstract: A gas turbine engine (10) comprising: a high pressure turbine (17); a low pressure turbine (19); a high pressure compressor (15) coupled to the high pressure turbine (17) by a high pressure shaft (27); a propulsor (23) and a low pressure compressor (14) coupled to the low pressure turbine (19) via a low pressure shaft (26) and a reduction gearbox (30); wherein the low pressure compressor (14) consists of four compressor stages (14) and defines a cruise pressure ratio of between 2.4:1 and 3.3:1; the high pressure compressor (15) defines a cruise pressure ratio of less than 17:1; and the high pressure compressor (15) and low pressure compressor (14) together define a cruise core overall pressure ratio of greater than 36:1.

Abstract: A method for monitoring at least one journal bearing for a shaft in respect to at least one acoustic event is provided. The at least one journal bearing is coupled with a gearbox, wherein a time dependent solid borne sound signal is detected by at least one solid borne sound signal sensor, the output signal of the at least one solid borne sound signal sensor is transmitted to a signal pre-processing device, frequency components of the solid borne sound signal with of more than 250 kHz are amplified in the signal pre-processing device and/or with a frequency of less than 50 kHz are attenuated in the signal pre-processing device, and the output signal of the signal pre-processing device is wirelessly transmitted via an antenna device to a signal evaluation device for the detection and/or location of the at least one acoustic event.

Abstract: A radial flux rotary electric machine having an exterior-rotor configuration is shown. The machine has a permanent-magnet rotor comprising permanent magnets in a Halbach array, and an air-cored stator interior to the rotor having teeth defining tapered slots and distributed windings around the teeth to form coils in a double-layer arrangement, the windings being comprised of a plurality of phase windings. For each tooth T having a slot S1 on one side thereof and a slot S2 on another side thereof, a coil side C1 of a phase winding is arranged to occupy a radially inner layer of the slot S1 and a coil side C2 of the same phase winding is arranged to occupy a radially outer layer of the slot S2, wherein the coil side C1 has a smaller circumferential dimension and a larger radial dimension than the coil side C2.

Abstract: An electro-discharge machining (EDM) device that includes a housing, an erosion electrode, a ground electrode, and a dielectric inlet. The housing is configured to be positioned on a surface of a workpiece and proximal to a fastener to be eroded. The planar erosion electrode is positioned at least partially within the housing, with the erosion electrode being movable relative to the housing in a first axis. The first axis is substantially normal to a longitudinal axis of the fastener. The ground electrode is conductively connected to the fastener. The dielectric inlet is configured to deliver a dielectric fluid to a region between the erosion electrode and the fastener.

Abstract: A gas turbine engine includes a fan mounted to rotate about a main longitudinal axis; an engine core, including a compressor, a combustor, and turbine coupled to the compressor through a shaft; and reduction gearbox; wherein the compressor includes a plurality of stages, each stage including a respective rotor and stator, a first stage of the plurality of stages being arranged at an inlet and including a first rotor with a plurality of blades; each blade extending chordwise from a leading edge to a trailing edge, and from root to tip for a span height, wherein 0% of the span height corresponds to the root and 100% of span height corresponds to tip; wherein a ratio of a leading edge radius of each of the plurality of first rotor blades at 0% span height to a minimum leading edge radius is comprised between 1 and 1.50.

Abstract: An engine for an aircraft includes an engine core having a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan having a plurality of fan blades; and a gearbox. The gearbox is an epicyclic gearbox and comprises a sun gear, a plurality of planet gears, a ring gear, and a planet carrier on which the planet gears are mounted. The radial bending stiffness of the planet carrier is equal to or greater than 1.20×109 N/m, and/or the tilt stiffness of the planet carrier is greater than or equal to 6.00×108 Nm/rad. A method of operation of such an engine is also disclosed.

Abstract: An apparatus for detecting a transient event in an operating machine, the apparatus comprising: a controller configured to control performance of the following steps: a measurement step comprising measuring a periodic signal from a machine; a processing step comprising synchronously processing the periodic signal to track the primary frequency; a filtering step comprising removing the primary periodic component and its harmonics from the periodic signal to yield a filtered dataset; an integration step comprising integrating the filtered dataset over the remaining frequencies to yield an integrated dataset representing the periodic energy at frequencies other than the primary frequency and its harmonics; an analysis step comprising identifying a short-term transient in the integrated dataset to identify a transient disruption in the operation of the machine.

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; a gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, and a front mount and a rear mount, the front and rear mounts being configured to connect the gas turbine engine to the aircraft, wherein the front mount is coupled to a casing of the engine core and the front mount is located at substantially the same axial position as a centre of gravity (CG) of the gas turbine engine or forward of the centre of gravity of the gas turbine engine.

Abstract: Gas turbine engines and methods of starting gas turbine engines, the gas turbine engine including: an electronic engine controller; one or more spools designated a starting spool for starting the engine, and has a required starting torque ?s; a permanent magnet alternator mechanically coupled with the starting spool, the alternator, in a motor mode, provides a peak torque of ?a, and, in a generator mode, generates electrical power for the electronic engine controller; and an electrical starter-generator mechanically coupled with the starting spool. The starter-generator in a motor mode, provides a peak torque of ?sg, and, in a generator mode, generates electrical power for an external load. ?sg+?a??s and ?sg, ?a<?s, and the electronic engine controller, during a start procedure, operates both the permanent magnet alternator and the starter-generator in a motor mode to drive the starting spool.