Abstract: Electrical distribution networks (9) are provided between an electrical power source (10, 42, 43, 50, 65) and electrical loads (11, 12, 13) in the form of a number of connections (A to G). Faults can occur within the electrical distribution network (9) resulting in fault electrical currents which may damage the network (9). An electrical protection arrangement comprises fault current flow detectors (A? to G?, AA, BB, AAA to DDD) in a hierarchy of levels defined by cascades of connections it is possible to utilise a controller to actively trip a circuit breaker associated with a respective fault current flow detector (A? to G?, AA, BB, AAA to DDD).

Abstract: Electrical power generation systems typically comprise an electrical power distribution arrangement in which a number of electrical power generators are coupled in parallel. In such circumstances in order to avoid conflict generally a first electrical power generator is controlled with a voltage controller whilst second electrical power generators have electrical current controllers. As loads are switched into and out of the electrical distribution system in normal operation the first electrical power generator and its voltage controller can accommodate voltage dynamics and therefore maintain a desired voltage. However, in order to accommodate heavier loads switching, the dynamic operation of the electrical current controller is achieved through utilising operational voltage margins from a desired voltage as control signals to the electrical current controller.

Abstract: Utilisation of a number of electrical machines such as generators all driven by a common prime mover, such as a gas turbine engine, are known. However, faults in one phase of one particular electrical machine may cause torque vibration and therefore stressing to mechanical linkages between the electrical machine and the prime mover. By determining torque vibration and then utilising a second electrical machine to introduce an anti-phase torque vibration a substantially balanced and steady torque loading to the mechanical linkages can be achieved.

Abstract: Electromechanical arrangements are utilised widely whereby a prime mover in the form of a mechanical assembly such as a gas turbine engine is utilised to drive an electrical machine as an electrical generator. Unfortunately the loads applied to the electrical generator may vary creating oscillation across phases of the electrical generator. Such oscillations generally will be translated to the mechanical assembly in the form of torque oscillations which may cause stressing. Stressing of the mechanical assembly will reduce its life and may alter its performance as well as fuel consumption. By provision of appropriate mechanisms for balancing electrical loads across an electrical machine as well reducing the time decay period for stored charge within an electrical assembly associated with an electrical machine it is possible to reduce torque oscillations as presented to the mechanical assembly and therefore improve its operational performance.

Abstract: With regard to cooling turbine blades in a gas turbine engine a compromise has to be made between convective cooling within the inner cavity defining a flow path for coolant and the blow rates for developing film cooling on an outer surface of the aerofoil. By providing a chamber between the flow cavity and external apertures reconciliation between the necessary flow rates for convective cooling within the cavity defining the pathway for coolant flow within the aerofoil and the necessary coolant blowing rate for film development can be achieved.

Abstract: An annulus filler (101) is provided for mounting to a rotor disc (102) of a gas turbine engine and for bridging the gap between two adjacent blades attached to the rotor disc (102). The annulus filler (101) has an outer part (106) which defines an airflow surface for air being drawn through the engine, and a separate, support part (105) which is connectable to the outer part (106) and to the rotor disc (102) to support the outer part (106) on the lo rotor disc (102). The outer (106) and support parts (105) are configured to allow a procedure for mounting the annulus filler (101) to the rotor disc (102). In a first step the support part (105) is connected to the rotor disc (102) without the outer part (106), and in a subsequent second step the outer part (106) is connected to the support part (105).

Abstract: An ejector, which finds particular application as a fuel injector for a gas turbine engine, has an axially located passage ending as a nozzle having an internal surface facing radially inwardly towards the axis and which extends as an outboard cone about the axis of the passage and which terminates at a tip. The cone has a profile which replicates the unconstrained trajectory of the fuel leaving the passage. The outer surface of the ejector has a profile for accelerating a gaseous flow over the outer surface. Atomisation of fuel is improved along with relight capability, flame extinction and smoke production.

Abstract: A sealing means for sealing between segments of a component assembly. The sealing means comprises a sealing member having a mating surface for mating with the surface of the segment. The sealing means further comprises a location member removably attached to the sealing member along a transition region therebetween, and also a free end distal to the sealing member. The location member is configured to engage a location feature of the segment so as to locate the mating surface of the sealing member in a fixed position on the surface of the segment relative to the location feature. The location member is configured to be detached from the sealing member along the transition region and be removed from the segment after the sealing member has been bonded to the segment.

Abstract: A method is provided of analysing measured parameter values, in relation to corresponding expected parameter values, from a system which has a plurality of associated system variables. The method includes the step of optimising an error function which relates said measured parameter values to the system variables. The step of optimising the error function includes adjusting the system variables to vary the expected parameter values and thereby vary the amount of error represented by the error function. A portion of the system variables are adjusted independently of each other. A further portion of the system variables are adjusted dependently of each other. In the further portion, the system variables remain in a predetermined constant ratio relative to each other, the predetermined constant ratio being characteristic of a known mechanism changing the performance of the system.

Abstract: Within generator systems maintenance of stability in terms of voltage is desirable. Generally, several generators will be arranged in parallel within the generator system with one generator voltage controlled to provide dynamic responsiveness to load switching. With regard to some loads which are generally of an active nature, the capacity of a first generator, which is voltage controlled, may be insufficient to adequately avoid transient voltage instability. By providing an actuator signal from a load to act as a pre-emptive or forward feed to an electrical current controlled generator, that second electrical current generator can be arranged to provide additional or reduced electrical current to avoid system voltage instability.

Abstract: A vibration damper assembly for damping non-synchronous vibration between adjacent, spaced apart components comprises a vibration damper located in both of a pair of generally confronting passages in each of the components. The assembly comprises at least two spaced apart articulation surfaces for contact between damper and component, each of the articulation surfaces is arcuate in a first direction and is characterised by having a substantially linear portion in an orthogonal and second direction. Thereby the contact area is greatly enlarged and material loss minimised. The cross-sectional shape of the damper or passage is non-circular and there is a clearance between the damper and passage sufficiently small to prevent rotation of the damper in the passage during use.

Abstract: Within such machines as gas turbine engines it is desirable to provide close association between rotating assemblies and a rotor path arrangement to reduce leakage. However, such arrangements of rotor assemblies and rotor path arrangements are subject to thermal cycling and differentials between the respective parts can lead to rub associations. In order to allow closer thermal responses between the respective rotor path arrangement and rotor assembly, a flexible assembly (8, 9, 10, 100) is provided for a liner (6). A face surface (5, 103) is presented upon a backer plate (10) or floating ring (101) such that the thermal response can be tuned to the reciprocal similar effects under the same conditions of the rotor assembly. In such circumstances, closer gap (111) control can be achieved. Furthermore, rather than requiring an entire integral casing to be overhauled, generally only the face surfaces (5, 108) and/or the flexible assembly will require remedial action.

Abstract: A method is disclosed for assembling a multi-stage compressor or a multi-stage turbine for use in a gas-turbine engine. The method comprises the steps of assembling a rotor drum so as to comprise a plurality of rotor discs 17, 18, and then releasably connecting a plurality of static components 38 to the assembled rotor drum 19, thus forming an intermediate structure. The intermediate structure is then inserted within an outer casing 50, preferably by lowering the outer casing 50 over the intermediate structure, whereafter the static components 38 are fixed to the outer casing 50. The static components 38 are then released from their connection to the rotor drum 19 in order to permit rotation of the drum 19 relative to the static components 38 and the outer casing 50.

Abstract: A retro-reflective sensor coating arrangement comprises a base layer of luminescent sensor material and an outer layer of optical bodies, such a spheres.

Abstract: An impingement cooling arrangement comprises a projection extending partially across a coolant passage upstream of a jet aperture. An end surface of the projection increases the available surface area for heat exchange with a cross flow whilst a coolant air flow jetted from the jet aperture can transgress a proportion of the air flow passing between the end surface and a junction surface incorporating the jet aperture. A spacing gap B between the end surface and the junction surface avoids localised distortions to the cross flow whilst the projection provides that the coolant air flow projected from the jet aperture mostly passes through a lower turbulence wake downstream of the projection for greater impingement upon a target surface for heat transfer and cooling efficiency. Typically the impingement cooling arrangement is incorporated within turbine blades or vanes of a jet engine.

Abstract: A ductile sheet includes an aperture for receiving a threaded fastener to secure the ductile sheet to a component. The ductile sheet includes a deformable region in which the aperture is defined, the deformable region being deformable out of the plane of the ductile sheet during tightening of the threaded fastener to secure the ductile sheet to the component.

Abstract: A method of determining the lift generated by a lift-generating member is presented. The lift-generating member being coupled to a component within the lift load path with the lift load path component experiencing strain as a result of the lift generated by the lift-generating member. The method involves the steps of coupling at least one strain measurement means to the lift load path component, obtaining strain measurements from the strain measurement means, and calculating the lift generated by the lift-generating member from strain measurements.

Abstract: A fluid vectoring nozzle comprises flow vectoring means suitable for selectively producing a fluid dynamic throat in the nozzle in a plane oblique to the axis of the nozzle, such that in operation fluid flow passing through the throat is rotated about an axis parallel to and coincident with the plane of the throat. That is to say, the present invention comprises flow vectoring means suitable for selectively producing a fluid dynamic throat in the nozzle in a plane oblique to the axis of the nozzle, such that, in operation, fluid passing through the fluid dynamic throat is turned towards an angle perpendicular to the plane of the throat. Fluid injection means are provided to inject a control fluid into the nozzle through a perforate region provided in at least one nozzle wall, thereby generating a fluid dynamic restriction which initiates the formation of the fluid dynamic throat.

Abstract: A fan casing for a gas turbine engine has a fan track liner extending only over an upstream part of the fan blades, and the local stiffness and internal shape of the casing are arranged to promote the break-up of a released fan blade while permitting the leading edge region of the blade to pass through the fan track liner and be contained by the fan casing. This arrangement is particularly suitable for fan blades in which the stiffness and compressive strength are significantly higher in the leading edge region than in the remainder of the blade; for example, hollow metal fan blades or composite fan blades having a metal leading edge cap.

Abstract: A leaf seal arrangement is provided in which within a housing there are edge portions to inter associate with non parallel chamfer edges in leaf seal elements. In such circumstances, deflection of the leaf seal elements in an outward direction or inward direction relative to a rotating shaft creates variation in a control gap X, XX between the edges and the chamfer edge. Such increase or decrease in the control gap X, XX adjusts the aerodynamic radial force that is presented to the leaf seal elements whereby those elements can be more accurately maintained at a desired leaf position for optimizing leakage whilst achieving better wear resistance performance.