Abstract: A method of optimising the design of a component is provided, in which a set of principal design variants is generated, the variants having design parameters which are common to all design variants of the set and some which differ between variants. Subsets of secondary design variants are generated by a computer executed rule based geometry engine, the subsets comprising at least one secondary design variant, generated by modifying at least one design parameter or design variable of the principal design variant.

Abstract: A seal and method of making seals utilizes folds in order to form creases in a length of material such that the creases reinforce individual seal elements or surfaces while perforations or slots in a seal edge allow air leakage from one side of the seal element or surface to the other. Thus, air pressurization can take place between spaced seal elements or surfaces and this allows air flotation or riding of a rotating component relative to a static housing component. The perforations are typically graduated from the seal edge in order to provide the best pressurization and air-riding effect for proximity or gap control between the sealing edge and the rotating component surface. The slots effectively provide flexibility to the sealing edge such that the seal component emulates a brush seal.

Abstract: A test piece for mechanical property testing, the test piece is generally elongate having two opposing surfaces. Each surface comprises at least one integral loading land. Preferably there are two lands on one surface and one or two on the other for three- or four-point bending testing.

Abstract: An actuator (12) is disclosed for example controlling gas flow in a gas turbine engine. The actuator (12) comprises a first portion (14) having shape memory properties, and a second portion (16) formed of substantially the same material as the first portion and having reduced shape memory properties relative to the first portion. The first portion (14) is movable from a first position to a second position at a temperature above the phase transition temperature of the shape memory material of the first portion (14). The second portion (16) is arranged to urge the first portion (14) from the second position to the first position at a temperature below the phase transition temperature of the shape memory material.

Abstract: There are a number of sensors (2, 22) such as thermocouples which can provide a putative measurand signal which is within a predicted range for such signals whilst the sensor is incorrectly operating, such as as due to an open circuit. Techniques and processes are available to determine by interrogation sensor operational validity, but these can distort the measurand signal if correct. By time division multiplex techniques the present arrangement takes a putative measurand signal from a sensor (2, 22) in order that either within the same time division or more normally a separate time division, an interrogation of the sensor is performed in order to determine accuracy and therefore validity of the sensor 22.

Abstract: Vanes are generally hollow with a passage through which service pipes extend. These service pipes must be connected such that they can allow for thermal expansion and contraction but also anti rotation features are needed in order to prevent damage when a supply coupling is connected through a pipe end. This anti-rotation feature is generally provided between a top hat and a pipe end through flanges. In order to allow reduced spacing between the top of the vane and a casing the flanges are arranged to allow at least recessing of a first flange into a passage opening profile whereby those flanges inter-engage with second flanges at a surface interface to prevent rotation.

Abstract: A catcher pin assembly for attachment to a catcher link of an aircraft frame, the catcher pin assembly comprising an engine mounting element 23, a catcher pin 23D, a compressible element 40, 41, 42, 43, and a nut 38 which is lockable to the catcher pin 23D, the compressible element 40, 41, 42, 43 being compressed between the pin and the mounting element and/or between the mounting element and the nut 38, in the assembled condition of the assembly, such that the compressible element 40, 41, 42, 43 applies a predetermined resistance to rotation of the catcher pin 23D relative to the mounting element 23. The invention also relates to a method of testing a catcher pin assembly to determine if the catcher pin 23D is carrying load from the catcher link, the method comprising applying a predetermined torque to the catcher pin 23D sufficient to overcome the resistance to rotation of the catcher pin 23D when it is unloaded, and determining whether the catcher pin 23D rotates relative to the mounting element 23.

Abstract: A load transfer arrangement is provided to act as a stabiliser for utilisation in centring rotational instabilities which may occur in rotor devices such as those within a gas turbine engine. By providing a fixed screw thread path which comprises a groove having channels and having constrictions and which define clearance crowns an acceptable eccentricity range it is possible to slow screw thread driving motion and therefore load transfer only to the positions where the rotational eccentricity enters tapers leading to the constrictions. In such circumstances an orbit thread is then progressively brought into confinement and continuous engagement with a fixed screw thread defined by crowns of channels of the fixed screw thread path defined by the continuous groove through the channels. In such circumstances wide eccentricity is allowed initially but as rotational speed reduces greater and more continuous driving motions are provided whilst avoiding excessive loading during early stage operation.

Abstract: Apparatus and a method of detecting combustor rumble in a gas turbine engine having combustion equipment that is susceptible to combustor rumble. The method has steps of: locating a dynamic pressure transducer remotely from the combustion equipment; connecting a conduit between the transducer and a location in the engine remote from the combustion equipment and subject to pressure fluctuations due to the combustor rumble; and measuring the pressure fluctuations using the transducer to detect combustor rumble.

Abstract: In a hot isostatic pressing (HIP) process, for example for securing blades (5) to a disc (3) to form a blisk (1), the temperature of the powder (6) to be consolidated is raised to a predetermined temperature, which may be the eventual required pressing temperature, before the pressure rise to the pressing pressure is initiated. If the powder is a titanium alloy and the process employs steel tooling pieces, the application of pressure occurs only when the temperature has risen to the extent that the steel is harder than the titanium alloy.

Abstract: The present invention relates to a test blade for a blade-release test. The blade is arranged in use to be mounted on a hub for rotation, and to be released therefrom by the action of a controlled explosion. The blade is arranged to receive at least one explosive charge and at least one detonator for detonating the charge. The blade further comprises a cut-through portion extending completely through the blade from a front face to a rear face, the cut-through portion also extending part way along the blade in an axial direction between a leading edge and a trailing edge of the blade.

Abstract: A composite component such as a fan rear seal comprises a hub and a body of composite material which is moulded over the outer periphery of the hub. The body is formed from a preform of fibre reinforcement impregnated with a resin, in a compression moulding process. The body has an annular projection provided with a sealing surface. The sealing surface may comprise circumferential fins, or may be a surface of, for example, an abradable seal insert moulded into the composite material of the body.

Abstract: A ventilation arrangement for an annular cavity located about the core engine of a gas turbine, the annular cavity having an axis and an inner wall located about the axis and an outer wall radially spaced there-from, the outer wall being interposed between the cavity and an engine bypass duct. The ventilation arrangement comprises a plurality of ventilation ducts passing through said outer wall and providing for fluid communication between the bypass duct and the cavity and a flow diverter arranged at an oblique angle to a radial alignment with said axis so as to induce in the ventilation flow from said ducts a vortical flow component about the inner wall. The ducts may be shaped to provide the flow diverter. The internal geometry of the ducts may provide for a sudden expansion to control the exit profile of the flow into the cavity.

Abstract: The tips of gas turbine engine turbine rotor blades are provided with an abrasive layer and the abrasive layer comprises chromised silicon carbide grit protruding from a layer of material. In particular the abrasive layer comprises a mixture of cubic boron nitride grit and chromised silicon carbide grit and the cubic boron nitride grit and the chromised silicon carbide grit protruding from the layer of material. The cubic boron nitride grit has a greater dimension than the chromised silicon carbide grit. The cubic boron nitride grit cuts the majority of a track in an abradable structure and then the chromised silicon carbide grit provides any additional cutting of the abradable structure.

Abstract: Fluid release apparatus (26) for the release of fluid from the interior of a rotating and/or pressurised body (16;18;102;104), the apparatus comprising a core member (28) having a chamber wall (44) disposed thereabout so as to define an open chamber (30) about said core member. The apparatus further comprises a chamber closure (48) mounted about said core member (28), said closure being resiliently deformable between an at rest state in which the closure contacts the chamber wall (44) and an actuated state in which the closure is spaced there-from, wherein the chamber has an aperture (32;35;55) for receiving liquid phase fluid from the interior of said rotating body. Upon build up of sufficient liquid in said chamber (30) the closure (48) moves to said actuated state so as to release liquid from the interior of the body.

Abstract: A gas turbine engine (10) having a pressure-rise combustor (30) and the pressure-rise combustor (30) is positioned upstream of a stage of turbine nozzle guide vanes (32). The vanes (33) of the stage of turbine nozzle guide vanes (32) forms an ejector and each of the vanes (33) has an upstream portion (34) and a downstream portion (36). The upstream portions (34) of the vanes (33) have leading edges (38) and the upstream portions (34) are arranged substantially straight and parallel to define constant area mixing passages (40) for a flow of gases there-through. The downstream portions (36) of the vanes (33) are arranged at an angle to the upstream portions (34) of the vanes (33) to turn the flow of gases there-through.

Abstract: A method is provided for analysing blade displacements detected by a plurality of circumferentially spaced stationary timing probes associated with an assembly of rotating blades mounted on a rotor. The blade displacements correspond to the times at which the blades pass the respective probes.

Abstract: An airfoil has a hollow shell providing external airfoil surfaces, and a corrugated core within the shell. The core contacts inner surfaces of the shell to support the shell. The airfoil is formed by consolidating a hollow shell pre-form and a corrugated core pre-form. At least a part of the hollow shell has a leading edge shell portion and/or a trailing edge shell portion which, before consolidation of the pre-forms, is a unitary body having a shape which wraps around the respective edge.

Abstract: A gas turbine engine variable area exhaust nozzle has a plurality of first and second movable members arranged circumferentially around a fan casing extending in downstream. The first and second movable members alternate around the variable area nozzle. During cruise conditions the first and second movable members are in un-actuated positions. At take off conditions the first movable members are in an actuated position and the second movable members are in the un-actuated position. At top of climb conditions the first movable members are in the un-actuated position and the second movable members are in an actuated position. The first movable members move radially outwardly from the un-actuated position to the actuated position and the second movable members move radially inwardly from the un-actuated position to the actuated position.

Abstract: The present invention relates to a rotational bearing assembly (1) comprising a pivot pin (40) and a rotation member (20) having an aperture (22) within which the pivot pin is located such that the rotation member can rotate relative to the pivot pin. A bearing (50) is at least partially disposed between the pivot pin and rotation member. The bearing has an axial portion (54) which extends axially within the aperture of the rotation member and at least partly over the pin, and first and second flanges (56) which extend at least partly over upper and lower edges of the aperture.