Abstract: A rotor stage (100) of a gas turbine engine (10) comprises a platform (120) from which rotor blades extend. The platform is provided with a circumferentially extending damper ring (200), the damper ring having an engagement surface (210) that engages with a platform engagement surface (110) of the platform (120). In use, the damper engagement surface (210) and the platform engagement surface (110) move relative to each other in a radial direction, in response to diametral mode excitation. This causes friction between the two surfaces, thereby dissipating energy and damping the excitation. The rotor stage (100) is arranged such that the engagement load between the damper engagement surface (210) and the platform engagement surface (110) is a function of the rotational speed of the rotor stage (100).

Abstract: A fuel injector system with a fuel feed arm extending inwardly from an outer casing of combustion equipment of a gas turbine engine to a flame tube of the equipment, which ends in an injection nozzle which penetrates a head of the tube to deliver fuel. The system has a swirler arranged coaxially with the nozzle at the head of the tube, including one or more circuits which produce flows of swirling air around the fuel. A seal ring seals the nozzle to the swirler, the nozzle being removably inserted into the ring. The ring has a flange portion, and the swirler has a pair of spaced retention grooves at a front face thereof. Opposite edges of the flange portion slidingly locate in the grooves so it sealingly engages to the front face. The swirler has a spring mechanism which retains the flange portion in the grooves.

Abstract: A rotor stage of a gas turbine engine includes a platform from which rotor blades extend. The platform is provided with a circumferentially extending damper ring, the damper ring having an engagement surface that engages with the platform. The damper ring provides damping through slip between the engagement surface and the platform. The damper ring has a hoop stress that results in a load being provided to the platform from the engagement surface. The load can be optimized in order to provide improved damping.

Abstract: A rotor stage (100) of a gas turbine engine (10) comprises a platform (120) from which rotor blades extend. The platform is provided with a circumferentially extending damper ring (200), the damper ring having an engagement surface (210) that engages with the platform. The damper ring has a cross-sectional shape perpendicular to the circumferential direction that has a depth (a) in the radial direction, and a neutral bending axis (250) that is spaced (b) from the engagement surface by more than half of the depth. Increasing the spacing between the engagement surface and the neutral bending axis increases the amount of slip at the interface between the damper ring and the platform, thereby increasing the amount of frictional damping.

Abstract: Combustion equipment includes annular combustion chamber having an annular upstream wall structure. Annular outer casing surrounds and is spaced from annular combustion chamber and annular inner casing is within and spaced from annular combustion chamber. Ogee shaped annular cowl is positioned upstream of annular upstream wall structure and a stage of compressor outlet guide vanes is positioned upstream of annular cowl. Pre-diffuser extends in downstream direction from stage of compressor outlet guide vanes, pre-diffuser is positioned upstream of cowl. Stage of compressor outlet guide vanes is connected to outer and inner casing. Outer fairing extends radially inwardly from outer casing such that annular outer casing, outer fairing and pre-diffuser define annular outer cavity and outer fairing is spaced from cowl or inner fairing extends radially outwardly from inner casing such that annular inner casing, inner fairing and pre-diffuser define an annular inner cavity and inner fairing is spaced from cowl.

Abstract: A method provides for measuring an assembled component including two or more parts, the method including the steps of: providing the component with a plurality of unique markers for detection during a scanning process; defining a first of the unique markers and aligning the first defined unique marker with a first element of the component; defining a second of the unique markers and aligning the second defined unique marker with a second element of the component; scanning the component and unique markers to capture a digitised version of the component and the relative positions of the first and second defined unique markers; and aligning a nominal CAD model of a part of the component with the equivalent part of the digitised version of the component using the relative positions of the first and second defined unique markers.

Abstract: A friction welding tool having a main body and a first clamp for gripping a first weld component and a second clamp for gripping a second weld component, at least one of the clamps being movable with respect to the other to effect friction welding of the respective weld components. The friction welding tool includes a vibration damper arrangeable to absorb vibrations of the first weld component during the friction welding. The friction welding tool includes an anchor element arranged to couple the damper to the main body of the friction welding tool to transfer absorbed vibrations to the main body.

Abstract: A system for countering the rolling motion of a marine vessel, includes one or more sensors adapted to characterise a sea condition approaching the vessel, one or more control systems, a computer, and one or more active stabilisers. The computer is adapted to receive the characterised sea condition data, is further adapted to generate one or more control signals in dependence on the characterised sea condition data, and is still further adapted to transmit the or each control signal to the or each control system. The or each control system is in turn adapted to actuate the or each active stabiliser in response to receipt of the or each control signal, to counter the rolling motion of the marine vessel.

Abstract: A method for detecting a fault in an exciter circuit, suitable for use in a brushless generator, the exciter circuit including (a) an exciter armature winding, having a plurality of armatures, arranged to generate a multiphase AC signal, each armature of the plurality of armatures providing a respective sub-signal component of the multiphase AC signal, and (b) a rectifier circuit for receiving the sub-signals via the respective armatures, the rectifier circuit comprising a plurality of components arranged to rectify the sub-signals to provide a rectified output signal, wherein the method includes the steps of: acquiring a respective operational sub-value for a first characteristic of each of at least two of the respective sub-signals; deriving an operational value indicative of a relationship between the acquired respective operational sub-values; determining whether a fault has occurred in the exciter circuit on the basis of the derived operational value.

Abstract: A control system for a machine comprising a plurality of independently replaceable machine modules comprises a controller operable to control operation of the machine. Memory stores machine data for use by the controller. Communication means are operable to provide communication for data transfer between the controller and the memory. The memory includes a plurality of memory modules associated with respective machine modules. Each of the memory modules is replaceable with the respective associated machine module and independently of other memory modules. The communication means is operable to provide communication for data transfer between the controller and a replacement memory module associated with a replacement machine module.

Abstract: A method of modelling at least a part of a gas turbine engine, method including: determining whether a first match feature data entity, defining a first location where a first physical feature may associate with another physical feature of a data structure, and a second match feature data entity, defining a second location where the second physical feature may associate with another physical feature of the data structure, satisfy a first matching criterion, the data structure including: a first data entity representing a geometrical shape of the first physical feature, the first data entity being associated with the first match feature data entity; and a second data entity representing a geometrical shape of the second physical feature, the second data entity being associated with the second match feature data entity; and performing relative movement between the first physical feature and the second physical feature within a model using the determination.

Abstract: There is disclosed an aero gas turbine engine comprising a compressor and an array of variable inlet guide vanes for the compressor. The angle of the variable inlet guide vanes is controlled by scheduling, the scheduling comprising a first component invoked for engine ground start and a second component invoked for engine in-flight windmill start at least under particular flight conditions. The angle of the variable inlet guide vanes required by at least a portion of the second component is greater than the angle of the variable inlet guide vanes required by at least a portion of the first component.

Abstract: A flexible tool comprising: a plurality of rigid members spaced along a longitudinal axis; a plurality of flexible members extending between the plurality of rigid members and being arranged to enable the plurality of rigid members to diverge from the longitudinal axis and define a work volume for the flexible tool, at least some of the plurality of flexible members being unevenly spaced around the longitudinal axis, and/or a physical characteristic of at least some of the plurality of flexible members varying along the longitudinal axis, to cause the work volume and/or stiffness of the flexible tool to be asymmetric relative to the longitudinal axis.

Abstract: A method of modelling at least a part of a gas turbine engine, the method comprising: preparing a model of at least a part of the gas turbine engine using a data structure including: a first set of data entities representing geometrical shapes of physical features; and a second set of data entities representing geometrical shapes of aerodynamic boundaries, the second set of data entities being used to preserve aerodynamic design intent during preparation of the model.

Abstract: A machine tool comprising: a first body; a first leg, a second leg, and a third leg coupled to the first body via first joints and configured to support at least the first body; a second body including a tool holder; a fourth leg, a fifth leg, and a sixth leg coupled to the second body via second joints and configured to support at least the second body; and a first actuator coupled to the first body and to the second body, the first actuator being configured to cause rotational motion between the first body and the second body to enable a change in walking direction of the machine tool and/or to enable a change in machining stiffness and a change in work volume of the machine tool.

Abstract: A method of modelling at least a part of a gas turbine engine, the method comprising: generating a mesh for a feature using at least one data entity of a data structure, the at least one data entity defining a geometrical shape of the feature, wherein the data structure comprises: a set of data entities defining geometrical shapes of features; and modelling attributes associated with the geometrical shapes of the features; and assigning one or more modelling attributes using the modelling attributes associated with the geometrical shapes of the features.

Abstract: A fluid heat management system for an aircraft gas turbine engine. The system includes an oil to air heat exchanger configured to transfer heat from engine oil to bypass air, an oil to fuel heat exchanger configured to transfer heat from engine oil to fuel, and a phase change material in thermal contact with the oil upstream of the oil to fuel heat exchanger. The phase change material has a phase change temperature at a predetermined fuel target temperature.

Abstract: An aerofoil having a leading edge point within a leading edge region and a pressure surface with a profile wherein within the leading edge region the pressure surface profile has a local minimum. The local minimum reduces the loss which may be caused by high negative incidence on to the blade.

Abstract: The present invention provides a rigid raft formed of rigid composite material. The raft has an electrical system and/or a fluid system embedded therein. The raft further has a tank for containing liquid integrally formed therewith. The tank can be formed of the rigid composite material. The tank can be for a gas turbine engine.

Abstract: A roller assembly for a rotary dresser comprise a plurality of axial segments which may be in the form of discs, each disc provided with an abrasive, radially outer surface. The discs are secured in axial alignment, each in a preconfigured rotational orientation. The disc assembly has a centrally arranged aperture for receiving a rotor shaft. The abrasive surface of the assembly can be accurately presented as an array of uniformly shaped abrasive units in a predefined pattern.