Abstract: A strain sensor apparatus for a rotatable shaft including a radiation emitter/receiver, a vibration element attached to the shaft and a radiation-reflective annulus surrounding the shaft and vibration element.

Abstract: A blade having a root portion and an aerofoil portion, wherein the aerofoil portion has a tip remote from the root portion, and a leading edge and a trailing edge, and wherein the tip of the aerofoil portion has a set-back portion extending from the leading edge or the trailing edge of the aerofoil portion part way towards the respective other edge and set back from the remainder of the tip of the aerofoil portion towards the root portion.

Abstract: A turbomachine casing assembly including a casing adapted to encase an aerofoil structure, the aerofoil structure having a tip, a leading edge and a trailing edge, the casing substantially surrounding the tip of the aerofoil structure, wherein the casing has a set-back portion extending from a position in the region of the leading edge or the trailing edge of the aerofoil structure part way towards a position in the region of the respective other edge and set back from the remainder of the casing away from the aerofoil structure, such that the set-back portion permits a flow over a corresponding portion of the tip of the aerofoil structure.

Abstract: The method described herein includes providing an aerofoil structure having a root portion and an aerofoil portion, wherein the aerofoil portion has a tip remote from the root portion. In certain aspects, the tip of the aerofoil structure can be substantially surrounded by a casing with a clearance gap between the tip and the casing. In certain aspects, the method described herein includes disposing the aerofoil structure relative to the casing such that an oscillation of the aerofoil structure from an unperturbed position in a first direction reduces the clearance gap and that an oscillation from the unperturbed position in a second direction increases the clearance gap. In certain aspects, the method further includes disposing the aerofoil structure such that the frequency of the clearance gap variation is equivalent to the frequency of the aerofoil structure vibration and permits a flow through the clearance gap in which the flow tends to dampen the aerofoil structure vibrations.

Abstract: A tip clearance control device adapted to control the clearance of a rotating aerofoil structure with a surrounding casing portion, and a method of controlling the tip clearance of a rotating aerofoil structure with a surrounding casing portion. The device includes a member operatively connected to the casing portion; the member having at least a first configuration in which the casing portion is at a first radial position and a second configuration in which the casing portion is at a second radial position, wherein the configuration of the member is controlled by magnetic flux in a magnetic circuit which includes at least one ferromagnetic element including ferromagnetic material, where the configuration of the member is responsive to the temperature of the ferromagnetic element.

Abstract: A gas turbine engine exhaust nozzle comprises a nozzle body defining a nozzle exit. An array of movable slats is disposed round the nozzle exit. Flow control walls are fixed to the nozzle body and provide flow control surfaces over which the movable slats move. The flow control walls prevent leakage of gas at the edges of the movable slats, so improving performance of the exhaust nozzle.

Abstract: An electrical machine comprising: a first stator member (16) having a field magnet (22); a second stator member (18) forming an armature, the second stator member (18) being spaced from the first stator member (16); and a pair of contra-rotatable rotors (12a, 12b) disposed between the first and second stator members (16, 18); wherein at least a portion (14) of each of the rotors (12a, 12b) is magnetisable so as to transmit magnetic flux between the field magnet (22) and the armature.

Abstract: A magnetic valve arrangement for controlling flow of fluid, the magnetic valve arrangement having at least one ferromagnetic element forming a portion of a magnetic circuit, a valve member and a valve seat; the valve member has a passage therethrough for the flow of fluid and is moveable between a first position, in which the valve member abuts the valve seat to restrict a fluid flow, and a second position, in which the valve member is spaced from the valve seat to allow a fluid flow into and through the passage in the valve member, wherein the position of the valve member is dependent on the temperature of the ferromagnetic element.

Abstract: A water jet propulsion device 10 for a water vehicle, such as a boat, is disclosed. The propulsion device 10 comprises a main duct 12 having a main inlet 14 that is arranged to be submerged in use and a main outlet 16, an impeller 30 disposed within the main duct 12 between the main inlet 14 and the main outlet 16, and at least one auxiliary duct 24 having an auxiliary inlet 26 that is arranged to be submerged in use and an auxiliary outlet 28 that opens into the main duct 12 upstream of the impeller 30.

Abstract: There is provided a water jet propulsion device 10 for a water vehicle, comprising a main duct 12 having a main inlet 14 that is arranged to be submerged in use and a main outlet 16; a pump disposed between the main inlet 14 and the main outlet 16; and a plurality of injection nozzles 40, 50, 60, 70 each arranged to selectively eject a jet of fluid into a different region A, B, C, D susceptible to cavitation, so as to re-energise the fluid flow in that region.

Abstract: An apparatus for pre-stressing a component, the apparatus includes means to direct a beam of radiation in a path through a medium adjacent to the component between a pair of electrodes to produce ionisation in the path through the medium and means to produce an electrical discharge between the pair of electrodes in the path through the medium to produce a pressure pulse in the medium adjacent to the component without the electrical discharge directly contacting the component, the pressure pulse impacting a surface of the component to produce a region of compressive residual stress within the component.

Abstract: An arrangement for controlling flow of fluid to at least one component of a gas turbine engine, the arrangement includes a first conduit for providing fluid to the component; a flow valve, for controlling the flow of fluid in the first conduit, having first and second configurations; a second conduit for providing fluid to the flow valve to the control the configuration of the flow valve; and a magnetic valve, for controlling the flow of fluid in the second conduit, having first and second configurations and including at least one ferromagnet forming a portion of a magnetic circuit; the member comprising ferromagnetic material is thermally coupled to one of the group comprising the fluid in the first conduit, the fluid in the second conduit and the component; and the configuration of the flow valve is dependent on the configuration of the magnetic valve.

Abstract: A method is provided whereby confidence in a validation parameter set is achieved by comparison with a known sample of a parameter in terms of the expected template comparison score as well as mean values and deviation from that score. Thus, with respect to user individual identification, biometric parameters such as fingerprint or handwriting or voice recognition can be utilised to compare the stored template for that individual with the putative biometric response in order to determine deviation from the mean. Previous systems provided a stored template and then ranging either side to simply give a pass/fail response. By adaptation of the ranging quotient for a particular individual, a percentage confidence in the pass/fail response can be achieved. For example an individual -may have a wider range of deviation than another individual and therefore close repetition of the biometric data may be indicative of a lower percentage confidence than with an individual with a narrower deviation.

Abstract: A joint including a first component and a second component. The second component including a shape memory material component. The first component has a half dovetail shaped slot and the shape memory material second component has a half dovetail shaped attachment feature disposed in the half dovetail shaped slot in the first component.

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: A shape memory material inductive heating arrangement comprising an array of coils capable of carrying an alternating electrical current and generating a magnetic field, a shape memory element having a first modulus and a second modulus, the second modulus greater than the first, characterised in that the array of coils and shape memory element are in effective range so that when an alternating current is passed through the coils the shape memory element is subject to the magnetic field and heated thereby, the induced heat sufficient to change the modulus of the shape memory material from the first to the second modulus.

Abstract: Actuators utilising shape memory alloy materials are known with regard to gas turbine engines. Such shape memory alloys have been used with respect to deformation provided in vanes and blades as well as nozzle elements in order that variations can be made in engine configuration dependent upon thermal cycling. Unfortunately, pedestals in order to provide spacing between the shape memory alloy and an antagonistic bias has resulted in uneven stress distribution as well as a higher thermal mass for the shape memory alloy. An uneven stress distribution will limit operational life whilst a higher thermal mass will result in slower reaction times. By separation of the shape memory alloy or material from its antagonistic bias through use of a slide element, a reduction in thermal mass is achieved and, more importantly, stress differentiation across the actuator is reduced.

Abstract: A strain sensor apparatus for a rotatable shaft including an emitter/receiver, a vibration element attached to the shaft and arranged for receiving and reflecting signals to and from the emitter/receiver wherein the vibration element includes asymmetric stiffness properties between a radial and axial and/or circumferential directions relative to a rotational axis of the shaft.

Abstract: A valve arrangement including a valve body and a valve seat each having an opposed surface, the valve arrangement also includes a high-frequency cyclic actuator to move the valve body with respect to the valve scat seat to bring the opposed surfaces into and out of abutment, characterised in that the opposed surface at least one of the valve body and the valve seat includes a resiliently displaceable surface.

Abstract: A strain sensor apparatus for a rotatable shaft including a radiation emitter/receiver, a vibration element attached to the shaft and a radiation-reflective annulus surrounding the shaft and vibration element.