Abstract: A control system operable includes a modified primary control parameter for an aircraft, the control system includes: a primary control parameter leg configured to output a demand in an aircraft primary control parameter; a primary control parameter compensation leg configured to receive a change in absolute levels and/or spatial distributions of swirl angle and/or fan pressure at a primary control parameter relative to a reference and convert the change into the primary control parameter; a processor adapted to receive the demand in the primary control parameter output from the primary control parameter leg and the change to the primary control parameter output from the primary control parameter compensation leg; compare the demand in the primary control parameter output from the primary control parameter leg and the change to the primary control parameter output from the primary control parameter compensation leg; and generate a modified primary control parameter for the aircraft.

Abstract: A method of estimating a parameter of a fluid flowing in a passage includes: having a plurality of instruments operable to measure one or more fluid properties flowing in the passage, the plurality of instruments being disposed in the passage and arranged within a common measurement plane; assigning a stream tube to each instrument, each stream tube represents a region of space in the common measurement plane within the passage and each stream tube surrounds one of the plurality of instruments, the stream tubes together correspond to the cross-sectional shape and area of the passage in the common measurement plane; measuring the one or more fluid properties using the instruments to obtain one or more measured values for each stream tube; using the measured value(s) for each stream tube to calculate a derived value for each stream tube; and summing the derived values across all of the stream tubes.

Abstract: A condensation irradiation system is disclosed comprising an electromagnetic radiation emitter mounted on a locating structure, the locating structure being arranged in use to position the radiation emitter so as radiation emitted therefrom travels through a condensation detection region adjacent an upstream side of a gas turbine engine fan.

Abstract: A method of processing data from a sensor, the method comprising: receiving first data; identifying an object by comparing the received first data with stored second data for a plurality of objects; determining a first processing strategy for one or more portions of the object in third data using the identification of the object, the third data being received from a sensor; and processing the determined one or more portions of the object in the third data using the determined first processing strategy.

Abstract: A switched reluctance generator and devices and methods for its control are concerned with generators and controls which can operate in an aerospace environment. The generator may have: a rotor having rotor poles; a stator having stator poles; and a controller. Either the rotor or stator poles each have windings to which current can be supplied to energise the poles and from which current can be drawn to a load; and the controller is arranged to: periodically excite each of the windings in turn to a pre-determined level of current; measure the current generated in each winding; cease the excitation when the current generated in each winding exceeds the excitation current; and direct the generated current in each winding to the load. The generator may thereby avoid the need to determine the position of the rotor poles relative to the stator poles to provide the commutation of the generator.

Abstract: A gas turbine engine, configured with a first chamber and a second chamber separated by a partition wall; wherein the partition wall includes a stationary element and a rotating element separated by a seal and either of the stationary element and the rotating element of the partition wall is segmented by a levered joint. The levered joint includes a lever having a trigger plate, a fixture portion and a fulcrum portion; and, the other of the stationary element and rotating element includes a hammer which is axially aligned and separated from the trigger plate in a first position, and forcibly contacts the hammer portion in a second position so as to create a moment on the lever via the trigger plate, the moment forcing the levered joint apart.

Abstract: A gas turbine engine arrangement comprising a gas turbine engine and an inlet screen. The gas turbine engine comprises an engine core comprising an inlet having a radial extent extending from an engine longitudinal axis to a first radial position, and a fan duct comprising an inlet having a radial extent extending from the first radial position to a fan casing, the inlet screen comprising an at least part annular porous grid radially extending across at least part of the radial extent of the fan duct inlet, and not extending across any substantial part of the radial extent of the core inlet.

Abstract: A gas turbine engine comprises a pylon attachment, a shaft defining an engine centreline which lies in an engine central plane intersecting the pylon attachment, a fan defining a fan plane normal to the engine centreline and an intake upstream of the fan plane. The geometric centreline of the intake coincides with the engine centreline at an axial position corresponding to the downstream end of the intake and curves away from the engine centreline upstream of said axial position. The engine may be mounted on one side of an aircraft such that the orientation of the highlight plane of the intake is aligned to the air flow field of the aircraft on that side during flight.

Abstract: A system, method and machine-readable instructions for monitoring a power electronics device. The system involves a semiconductor device, at least one sensor and a processor. The processor is configured to monitor a junction temperature of the semiconductor device by determining from the at least one sensor an on-state resistance of the semiconductor device and calculating the junction temperature of the semiconductor device according to a relationship between the on-state resistance of the semiconductor device and the junction temperature of the semiconductor device. The processor may apply an ageing coefficient to the on-state resistance.

Abstract: A machine having a plurality of sub-assemblies, having a geometric computational model is generated for the machine, including the sub-assemblies and one or more module of machine readable code defining how vibration is communicated through said geometric model. First and second instances of the computational model are run to generate outputs of loading throughout the machine geometry as a result of the vibration of the geometric model under a simulated machine operating condition. The first and second instances respectively includes the computational model with and without inclusion of vibration induced by a control system for one or more sub-assembly of the machine. A maximum loading threshold is determined for the machine. A threshold for one or more control parameter in the control system is set based on the contribution of the vibration induced by the control system to the maximum loading threshold.

Abstract: A gas turbine engine (100) for an aircraft comprises a pylon attachment (112) and a shaft (108) defining an engine centreline (110). The engine centreline lies in an engine central plane (120) which intersects the pylon attachment. The gas turbine engine comprises an intake (104) having a non-axisymmetric geometry and a medial plane (130) defining left and right halves of the intake. The left and right halves are configured for at least one of optimum cross wind performance, optimum incidence performance and optimum cruise performance when the medial plane is aligned with a vertical plane. The intake is installed so that the medial plane is angularly offset with respect to the engine central plane. The engine may be installed on a wing of an aircraft with the medial plane closer to its optimal orientation than is the case for a conventional engine.

Abstract: A powder deposition apparatus has a build plate, a powder source, a recoater arm, and an energy beam. The recoater arm is formed from ferromagnetic material. The recoater arm is arranged to deliver a layer of powder from the powder source across the working surface of the build plate prior to the energy beam fusing a predetermined portion of the delivered powder layer. The recoater arm comprises a magnetic portion.

Abstract: A mould for casting a component in a directional solidification casting process having a preferred direction of grain growth (non-axial <001>) comprises a shell defining a cavity for receiving molten material. The cavity defines a three dimensional shape made up of a finished component geometry portion (42, 43, 44) and a sacrificial geometry portion (45) wherein the sacrificial geometry portion (45) includes a notch (48) which is shaped and positioned so as to, in use, contain high angle grain boundaries between dendritic growth in the preferred direction (non-axial <001>) and dendritic growth in a competing direction to the preferred direction (axial <001>) within the sacrificial geometry portion of a casting solidifying in the mould.

Abstract: An assembly for mounting a circumferential shroud to a casing, including a plurality of arcuate shroud segments collectively forming the circumferential shroud. Each segment includes a circumferentially extending wall and a channel extending from the wall. The channel is receivable in a hole passing through a circumferential casing and has a first connector. A fastener has a head and a shank, which is receivable in the channel and has a second connector that engages with the first connector. A first spacer receives the channel and a second spacer receives the shank and sit adjacent the head of the fastener on either side of the casing. The spacers can be selected to adjust for optimal radial positioning of the shroud and of probes received within a space defined between the casing and the shroud for monitoring rotor speed and the tip air gap of a turbine rotor contained in the casing.

Abstract: A method of assessing a condition of a multi-phase power system comprises the steps of: acquiring a voltage signal and a current signal for each phase of the multi-phase power system; calculating a product of the voltage signal for each phase of the multi-phase power system with one of the current signals such that the product is between a voltage signal for one phase and a current signal for a different phase for at least two of the products; summing the calculated products; and identifying the possible existence of a fault in the multi-phase power system based on a frequency analysis of the summed calculated products.

Abstract: A method of friction welding a first workpiece to a second workpiece, includes the first workpiece with a first faying surface having a first faying length, the second workpiece with a second faying surface having a second faying length, the second faying length greater than the first faying length; positioning the first workpiece adjacent the second workpiece; reciprocating the first workpiece and the second workpiece against one another, the first faying moves relative to the second faying by a sweep length, a temperature at the first and second faying surfaces increases to create a weld interface; each of the first and second workpieces are consumed into the weld interface, adjusting the sweep length the sweep length remains equal to a difference between the second and the first faying lengths; and stopping the reciprocating and allowing the first and second workpieces to cool to weld the first and second workpieces together.

Abstract: A process of forming an aerofoil is provided. The process includes: providing a layered, planar pre-form; inflating and hot creep forming the pre-form to form an intermediate structure having aerofoil pressure and suction surfaces, and a front, edge-receiving portion joining front edges of the pressure and suction surfaces; providing a leading edge piece; and bonding the leading edge piece to the front, edge-receiving portion of the intermediate structure to form an aerofoil in which the leading edge piece forms an aerofoil leading edge.

Abstract: An aerofoil component (10) defining an in use leading edge (16) and a trailing edge (18), the leading edge (16) comprising at least one serration (22) defining a sawtooth profile projecting in a generally upstream direction, each serration (22) comprising a plurality of rectangular-wave projections (26) extending in an upstream chordwise direction from the sawtooth profile.

Abstract: Disclosed herein is a gimbal body comprising: an end part (51) for use in welding the gimbal body to a pipe; and a main body (53) attached to the end part (51); wherein: the end part (51) is made of a first material; and the main body (53) is made of a second material that is different from the first material. Embodiments provide a new method of manufacturing a gimbal that allows the use of the most appropriate materials for high temperature and high pressure performance whilst overcoming manufacturing and installation problems experienced by known gimbals constructed with such materials.

Abstract: A gearbox includes a sun gear, a plurality of planet gears, an annulus gear and a planet carrier. The planet carrier includes a first ring, second ring spaced axially from the first ring, a plurality of circumferentially spaced axles and a plurality of circumferentially spaced support structures extending axially between and secured to the first ring and second ring. Each planet gear is rotatably mounted on a respective one of the axles. The first ring has a plurality of circumferentially spaced recesses and the second ring has a plurality of circumferentially spaced recesses. Each recess in the second ring is aligned with a corresponding one of the recesses in the first ring. A first end of each support structure locates in a recess in the first ring. A second end of each support structure locates in a recess in the second ring. Each support structure comprises a fused powdered material.