Abstract: A turbine rotor assembly (32) comprising a turbine rotor (34) and a plurality of circumferentially spaced radially outwardly extending turbine rotor blades (36). The turbine rotor (34) has a rim (38) and a plurality of circumferentially spaced slots (40) provided in the rim (38) of the turbine rotor (34). Each turbine rotor blade (36) has a root (42) and the root (42) of each turbine rotor blade (36) is arranged in a corresponding one of the slots (40) in the rim (38) of the turbine rotor (34). Each of the slots (40) has a chocking device (50) and each chocking device (50) abuts a radially inner surface (52) of the slot (40) and each chocking device (50) abuts a radially inner surface (48) of the root (42) of the corresponding turbine rotor blade (36).

Abstract: Noise generated by a gas turbine engine 6 supported by a pylon 8 on a wing 2 of an aircraft is reduced by influencing a shear layer generated between the free-stream flowfield and flow from the engine 6. The shear layer is influenced by means of one or more winglets 18, 20, 22 which interact with the free-stream flowfield to deflect the shear layer 14 downwardly, to avoid interaction with a flap 4 on the wing 2, or to reduce the strength of the shear layer 14.

Abstract: A pylon is provided for attachment of a gas turbine engine to a wing of an aircraft. The gas turbine engine comprises a core fairing surrounding a core generator and defining a nozzle for discharging a core gas flow, and a fan nacelle surrounding the core fairing to define an annular bypass duct therebetween for discharging fan air. The pylon has a trailing edge which is rearward of the trailing edge of the core fairing and the trailing edge of the fan nacelle. The pylon further has having two laterally-spaced side faces which span the bypass duct between the fan nacelle and the core fairing and extend in the rearward direction of the engine to end at the trailing edge of the pylon. Each side face has a bottom edge which extends in a rearward direction of the engine from the core fairing to the bottom end of the trailing edge of the pylon.

Abstract: A composite turbomachine blade (34) comprises a composite material including reinforcing fibres in a matrix material, the turbomachine blade (34) comprises an aerofoil portion (36), a shank portion (38) and a root portion (40). The aerofoil portion (36) has a leading edge (42), a trailing edge (44). The composite turbomachine blade (34) also has a metallic protective member (52) arranged in the region of the leading edge (42) of the aerofoil portion (36) of the turbomachine blade (34). The metallic protective member (52) is adhesively bonded to the composite material in the region of the leading edge (42) of the aerofoil portion (36) of the composite turbomachine blade (34). The metallic protective member (52) has at least one metallic projection (56, 58) extending from the metallic protective member (52) towards the root portion (40) of the composite turbomachine blade (34).

Abstract: A compressor or fan is controlled to avoid stall, surge or flutter. The control system includes a look-up table from which is retrieved a margin-adjusted limiting value of a control parameter of the compressor, using inputs representing inlet guide vane angle (IGV), non-dimensional speed of the compressor (N/R?T), vehicle Mach number (Mn) and inlet geometry (IG). A variable stall, surge or flutter safety margin about a nominal limiting value of a control parameter is pre-established to reflect threats to the working, stall, flutter and surge lines, for example as a result of measurement inaccuracies, and from this the margin-adjusted limiting value is derived. An actual value of the control parameter is determined in real time, and the actual value is compared with the margin-adjusted limiting value. An output signal indicating stall, surge or flutter risk is generated if the actual value falls within the stall, surge or flutter safety margin.

Abstract: The invention relates to a method of querying technical domains that recognises the concepts represented by strings of characters, rather than merely comparing strings. It can be used to compute conceptual similarity between terms. The method employs string distance metrics and a cyclic progression of lexical processing to recognise constituent term concepts that are then combined to form full-term concepts by means of a grammar. Terms can be extracted and identified as being conceptually similar (or dissimilar) to other terms even if they have never previously been encountered. A key advantage is the ability to extract terms from documents based on the combination of a limited number of sub-concepts. This avoids the need for the prior identification of all possible terms that current methods require. A second key advantage is the ability to introduce or remove concepts and synonyms individually without the need to alter terms which the concept or synonym constitutes.

Abstract: A method for predicting initial unbalance in a component comprising one or more elements, the method comprising: defining a statistical distribution of a mass moment weight of each of the one or more elements; restricting the statistical distribution to a selected range; and calculating an initial unbalance of the component for the restricted distribution of the one or more elements.

Abstract: A gas turbine engine 2 is supported on an aircraft fuselage by a pylon 10 which carries a mounting ring 6. The mounting ring 6 is releasably coupled to an engine ring 8 on the casing of the engine 2, centred on the engine axis. A further member 12 extends from the pylon 10 and is secured to a location on the engine which is axially spaced from the mounting ring 6. The arrangement enables the engine 2 to be on the pylon in different orientations, to suit different mounting configurations on the aircraft 22.

Abstract: A press brake tool assembly mounting device 42 comprising a body 66 which mounts a lower press brake tool 46, with a recess in the body 66 receiving in a moving fit a location member 52 mounted to a lower beam 44. A locking arrangement 80 is provided for locking the body 66 relative to the location member 52 in a friction fit, to retain the lower press brake tool 46 in a required position.

Abstract: Aerofoils (22) of a gas turbine engine are provided with a coating (34) or filler (44) of viscoelastic material. As ice accretes on the aerofoils (22) during operation, the resulting aerodynamic stability imbalance induces vibration in the aerofoils (22). The viscoelastic material (34, 44) damps this vibration, and in so doing generates heat, which melts the ice away from the aerofoils (22). Heat-conducting members conduct the heat to regions of the component in which ice accretion is to be prevented. Alternative embodiments are described in which the pseudoelastic behaviour of a shape memory alloy (56), or eddy currents arising from the rotor blades' rotation in an axisymmetric magnetic field, are used as sources of heat.

Abstract: A high temperature measurement probe comprises an elongate probe body having a measuring head which in use is located in a hot fluid flow. The probe further comprises a thermocouple extending along the interior of the probe body to terminate at a temperature-sensing thermocouple junction inside the measuring head. The probe body has internal passages for circulation of a coolant fluid therein. The measuring head contains a channel, one end of the channel forming an inlet for receiving hot fluid from the hot fluid flow and another end of the channel forming an outlet for discharging the hot fluid received at the inlet. Between the inlet and the outlet a section of the channel extends along the length direction of the probe body. The thermocouple runs along the section of the channel with the thermocouple junction proximate the upstream end of the section.

Abstract: A method of heat treating a superalloy component includes solution heat treating the component at a temperature below the gamma prime solvus temperature to produce a fine grain structure. Insulation is placed over a first area to form an insulated assembly that is placed in a furnace at a temperature below the solvus temperature and maintained at that temperature for a predetermined time to achieve a uniform temperature. The temperature is increased at a predetermined rate to a temperature above the solvus temperature to maintain a fine grain structure in a first region, produce a coarse grain structure in a second region and produce a transitional structure in a third region between the first and second regions. The insulated assembly is removed from the furnace when the second region has been above the solvus temperature for a predetermined time and/or the first region has reached a predetermined temperature.

Abstract: A gas turbine engine (10) comprising a first turbine (19) and a first compressor (13) mounted on a first shaft (26) and a bearing arrangement (52, 34) supporting the shaft (26), the bearing arrangement is subject to a total end load and comprises a fixed bearing (34), a load share bearing (52) and a bearing end load management system (50) that is capable of applying a variable load to the load share bearing to manage total end load between the bearings. The bearing end load management system comprises a static diaphragm (54) that defines part of a chamber (56) and that is coupled to the load share bearing whereby increased pressurization of the chamber loads the diaphragm which in turn increases the proportion of the total end load on the load share bearing.

Abstract: Seal assembly for sealing a clearance gap between a boundary of an aperture formed in a housing and a member extending through the aperture. The seal assembly comprises a seal member and a seal member mounting means disposed around the sealing member and is configured to engage with the aperture boundary. The seal member mounting means is configured to seal an alignment interspace provided in the clearance gap between the seal member and aperture boundary. The seal member mounting means is configurable to permit the seal member to be located at a position relative to the aperture boundary in dependence upon the relative positions of the member and aperture boundary to thereby accommodate misalignment between the member and aperture boundary. The seal member mounting means is configurable to lock the seal member relative to the aperture boundary in said position.

Abstract: A seal having an integral attachment arrangement. The attachment arrangement comprises at least one attachment feature and at least one locking feature. The at least one attachment feature is configured and arranged to interdigitate with features of another component in a first orientation and to lock to the other component in a second orientation. The second orientation is rotationally displaced from the first orientation.

Abstract: Distributed generation systems incorporate a distribution network and typically a number of distributed generators. It is possible that power islands may be created in substations incorporating a generator when that substation and generator is isolated from the distribution network by a circuit breaker. A problem arises when the power island is re-connected to the distribution network when the phase of electrical power supply in the previous power island is not synchronized with the power supply on the distribution network. Identifying such an out of phase nature is achieved utilizing application of test reactances, both capacitative and inductive, across the whole distribution network such that such test reactances are substantially unbalanced within a particular substation and in particular a distribution path for a generator so that there is a test reactance load imbalance which will identify out of phase operation and therefore control activation of the circuit breaker.

Abstract: A mechanical arrangement for an engine having two propeller stages, including: a first epicyclic gear stage including a sun gear, a planet gear, a planet carrier and an annulus, wherein the sun gear is driven by a shaft of the engine, the planet carrier is stationary and thereby permits static structure to be located there through, and the annulus outputs torque and/or drive; a second epicyclic gear stage including a second sun gear, a second planet gear, a second planet carrier and a second annulus, wherein the second sun gear is driven by the annulus of the first epicyclic gear stage and is annular to accommodate the static structure, the second planet carrier includes the output to one of the propeller stages and the second annulus includes the output to the other of the propeller stages; wherein the static structure provides mounting for static components on one or both sides of each epicyclic gear stage.

Abstract: A flux-switching magnetic machine is provided having a drive element and a driven element. The drive element is configured to generate a composite magnetic field comprising a fixed component and a variable component, the fixed component being generated by spaced fixed field members and the variable component being generated by spaced armature windings. The driven element has a plurality of magnetisable portions configured to be coupled to the composite magnetic field generated by the drive element, such that the driven element moves in response to changes in this field. The number of fixed field members is greater than the number of armature windings.

Abstract: An engine mounting apparatus for attaching an engine to a suspension pylon includes a mounting block, first and second links connectable between the engine and the mount block and first and second fixings connectable between the suspension pylon and the mount block. The apparatus further has a catcher link, located between the first and second links, that is connectable to the engine at a first end and to the suspension pylon at a second end via a third fixing with a clearance between the catcher link and the engine such that no load is transferred between the engine and the suspension pylon in normal operation. The apparatus also has a catcher fixing between the mount block and the catcher link, the catcher fixing having a clearance with respect to the mount block such that no load is transferred between the mount block and the catcher link in normal operation.

Abstract: A rotor arrangement has a rotor-section and a circumferential moveable seal around the rotor-section. The arrangement being such that, for a given rotation rate, the rotor-section is subject to an associated radial growth and a corresponding related axial displacement, relative to the seal. The rotor-section is provided with an axially-varying profile for off-setting said radial growth of the rotor-section, adjacent the circumferential seal, at said given rotation rate.