Abstract: A combustor for a gas turbine engine comprising a combustion chamber wall having formed therein at least one hole for admitting air into the combustion chamber and at least one air intake chute aligned with said hole. The air intake chutes are attached to the combustor wall in regions which, during operation, will be regions of low stress concentration.

Abstract: A disc component 2 for a gas turbine engine is produced from a workpiece 4 by a sequence of machining operations. During the machining operations, the workpiece 4 is supported by a fixture 36 engaging support surfaces 32, 34. The workpiece 4 remains secured to the fixture 36 throughout the sequence of machining operations so that these operations can be conducted on both faces 26, 28 of a disc portion 8 of the workpiece 4 without removing the workpiece 4 from the fixture 36. The machining operations are conducted alternately on the opposite faces 26, 28 in order to allow residual stresses in the workpiece 4 to dissipate in a controlled manner.

Abstract: In a laser shock peening process, the shape of the spot 26 generated by the laser beam 4 is changed on the fly. This is achieved, for example, by a masking device 30 which is movable into and out of the path of the laser beam 4. Laser shock peening spots 24 can consequently be shaped so as to avoid the spots overlapping an edge of the workpiece, or any other feature which may be damaged by the laser energy.

Abstract: A gas turbine engine exhaust nozzle arrangement for the flow of exhaust gases therethrough between an upstream end and a downstream end thereof comprising a nozzle and a plurality of tabs which extend in a generally axial direction from a downstream portion of the nozzle wherein the nozzle further comprises an actuation mechanism capable of moving the tabs between a first deployed position, where the tabs interact with a gas stream to reduce exhaust noise thereof, and a second non-deployed position, where the tabs are substantially aerodynamically unobtrusive.

Abstract: A combustion chamber suitable for a gas turbine engine is provided with at least one Helmholtz resonator having a resonator cavity and a damping tube in flow communication with the chamber interior. The damping tube is provided with at least one cooling hole extending through its wall for improved damping and cooling.

Abstract: Methods for estimating performance of and/or detecting faults in components of a multi-component system, where the performance of each component is defined by one or more performance parameters x related to measurement parameters z that can be expressed as a function of the performance and operating parameters defining an operating condition of the system. The methods include: defining a series of fault classes corresponding to possible outcomes of faulty components; creating an initial population of strings for each fault class, each including a plurality of elements corresponding to the performance and operating parameters, values being assigned to the string elements which represent estimated values of said parameters and are constrained only to indicate fault affected values for performance parameters of the fault affected component of the respective class; and optimising an objective function which gives a measure of the consistency between measured and calculated values of the measurement parameters.

Abstract: A brush seal for sealing between a rotor and a stator of a gas turbine engine includes a housing and a plurality of flexible bristles held within the housing. The bristles protrude from the housing so that a free end of each bristle is able to contact and seal against a seal surface of the rotor. The brush seal further includes a stop member for limiting movement of the free ends of the bristles towards the seal surface of the rotor, in order to reduce wear on the bristles.

Abstract: Vane actuating apparatus for adjusting the angle of incidence of a set of variable angle vanes in a gas turbine engine comprises a plurality of vane actuator levers attached at one end to a respective vane and at the other end to actuation means for moving the vanes in unison. Each lever has an interlocking connection means for pivotally connecting the lever with respect to its respective vane in such a way that the lever is capable of being attached and detached from the vane at a first angular position, and retained in interlocking engagement for pivotal movement at a second angular position or range of positions.

Abstract: An air cooled bearing comprising means for imparting a swirl component to the cooling air flowing toward the bearing. By imparting a swirl component to the cooling air the amount of work imparted on the cooling air by the rotating cage and rolling elements of the bearing can be reduced and in some cases substantially eliminated.

Abstract: A friction vibration damper for damping the vibrations of a vibrating component comprising a body, a chamber and a plurality of elements, the body defines the chamber which is partially filled with the plurality of elements, the friction vibration damper, in use, disposed on or in the vibrating component characterized in that the friction vibration damper is configured to substantially prevent the elements operationally moving in a convection-like flow pattern.

Abstract: A gas turbine engine (10) fan outlet guide vane (34) is manufactured by diffusion bonding titanium alloy sheet metal workpieces (52, 54) together to form an in integral structure (66). A titanium alloy is weld deposited at predetermined positions (70, 72) and in a predetermined shape to build up bosses (42, 44) at the radially outer end (40) of the hollow integral structure (68). The integral structure (66) is inflated at high temperature to form a hollow integral structure (68) of predetermined aerofoil shape. Apertures (46, 48) are drilled through the bosses (42, 44) to enable the radially outer end (40) of the fan outlet guide vane (34) to be attached to a fan casing (32) of the gas turbine engine (10).

Abstract: A component, for example a fan blade for a gas turbine engine, comprises panels 2 and 4 which define between them a cavity containing a warren girder structure 6. Internal surfaces of the panels 2 and 4 are provided with a damping material 14, disposed between regions of contact 12 between the warren girder 6 and the panels 2, 4. The damping material damps vibrations of the component, so extending its fatigue life.

Abstract: A gas turbine engine system comprises a first compression stage; a second compression stage; a combustor; a controller; a first sensor for sensing the speed of the first compression stage and providing a first indication of the sensed speed to the controller; and a second sensor for sensing the speed of the second compression stage and providing a second indication of the sensed speed to the controller, wherein the controller is operable to control the supply of fuel to the combustor in dependence upon the first indication received from the first sensor and the second indication received from the second sensor. This arrangement is particularly useful in controlling the acceleration of an aero-engine from minimum idle.

Abstract: A control system comprises: a plurality of input devices; a plurality of remote output devices; a plurality of dedicated connections and a digital data network interconnecting the plurality of input devices and the plurality of remote output devices. Each one of the plurality of output devices is connected to one of the plurality of input devices by an associated one of the plurality of dedicated connections. Each output device is operable to detect an addressing error in the digital network by comparing a value of a parameter received via its dedicated connection with the value of the same parameter received via the digital data network. Each output device is operable to use a network address dependent upon a value received via its dedicated connection.

Abstract: A gas turbine engine turbine section includes a turbine disk (20) which carries a stage of turbine blades (22). The turbine blades (22) have fir tree roots (24) which locate in fir tree grooves (26) in the rim of disk 20. Some of the projections that form the fir tree roots (24) of blades (22) and fir tree grooves (26) of disk (20) are truncated so as to define spaces between their truncated surfaces and the roots between adjacent overlapping projections, thus enabling the passing of a cooling air flow therethrough.

Abstract: The present invention provides an ultrasonic transducer structure, comprising a first ultrasonic transducer element (1), arranged and operable for transmitting an ultrasonic signal from a front face of the structure, damping material (2) at the back of the first ultrasonic transducer element (1), and a second ultrasonic transducer element (3) in or on the damping material behind the first ultrasonic transducer element (1), arranged and operable to receive sound energy propagated through the damping material (2) when the first ultrasonic transducer element (1) is operated to transmit an ultrasonic signal from the front face.

Abstract: A method for determining the total mass flow through an engine (10) comprises measuring (32) the fuel flow to the engine (10) and measuring the concentration of carbon dioxide in the gases exhausted (22) from the engine (10). The concentration of carbon dioxide is measured by detecting the infrared radiation absorption spectrum of carbon dioxide using a laser (38) and a detector (46). The method comprises determining (48) the air to fuel ratio in the engine (10) from the fuel flow and the concentration of carbon dioxide. The method comprises determining (48) the air mass flow through the engine (10) from the air to fuel ratio and calculating (48) the total air and fuel mass flow through the engine (10) by adding the air mass flow through the engine (10) to the fuel mass flow to the engine (10).

Abstract: The present invention relates to laser deposition and more particularly to use of deposition wire (5, 21) in order to create structures or components. The original deposition wire (5, 21) is reconfigured in order to increase its lateral dimension and so provide a greater overlap with a presented beam (3) from a laser (2). The presented beam (3) therefore more consistently melts the presented reconfigured deposition wire (31, 41, 51, 61, 71, 81) in order to form the desired structure or component.

Abstract: A method and system for detecting an anomaly in a fluid system, comprising exposing a sample of the fluid system to a first, non-oscillating magnetic field, simultaneously exposing the sample to a second, oscillating magnetic field orthogonal to the first field, modulating one or both of the magnetic fields, and detecting and capturing a resulting NMR signal from the sample. An analysis of the captured signal, typically involving transformation of the signal into an NMR frequency domain spectrum, can be performed to look for specific changes in the signal indicative of the presence of a particular anomaly.

Abstract: An electrical machine comprises a combined magnetic gearbox and electrical generator. A first set of permanent magnets (30) are arranged on a rotor (16) to produce a spatially variable first magnetic field. A second set of permanent magnets (32) are arranged on a rotor (40,41,43), stationary pole pieces (36) are positioned between the first set of permanent magnets (30) and the second set of permanent magnets (32) to interfere with the first magnetic field. Rotation of the rotor (16) relative to the pole pieces (36) produces a second magnetic field which rotates the second set of permanent magnets (32). A stator (42) has windings (46) to transduce a changing second magnetic field produced by the rotation of the second set of permanent magnets (32) into an electrical voltage. The electrical machine is useful for a wind turbine generator. Alternatively the arrangement may be modified to produce an electrical motor.