Abstract: A gas turbine engine sealing air system including a bearing chamber seal to prevent lubricant fluid loss from a fluid chamber, the sealing effected by ingress of sealing air. The system includes an air vent duct coupled to the bearing chamber seal. An ejector is located within the air vent duct to pump sealing air from the bearing chamber seal and through the air vent duct. A first duct is coupled between a starter air system of the gas turbine engine and the ejector to provide motive fluid to the ejector during gas turbine engine starting.

Abstract: A gas turbine engine sealing air supply system comprising a bearing chamber seal to prevent lubricant fluid loss from a fluid chamber, the sealing effected by ingress of sealing air. An air supply duct is coupled to the bearing chamber seal to provide the sealing air. A first duct is coupled between a starter air system of the gas turbine engine and the air supply duct to supply sealing air during gas turbine engine starting.

Abstract: A combustor in a gas turbine engine has a wall which forms a gap with an outer nozzle guide vane platform. A closure mechanism is operable to open or close the gap. Opening of the gap, for example during cruise conditions, reduces the mass flow rate of air through an open end of the combustor, so enriching the air fuel ratio and improving flame stability and combustion efficiency. Under high power conditions, the gap is closed, causing an increase in air flow rate through the open end to achieve a lean burn air fuel ratio when the fuel flow rate is increased.

Abstract: A method of producing a component includes the steps of: providing a workpiece generated by hot isostatic pressing a powder metal form; and electropolishing a surface of the workpiece to remove a substantially uniform surface layer of the workpiece to produce the component. Following the electropolishing step, the component has substantially the same shape as the workpiece produced by the hot isostatic pressing step.

Abstract: An anti-vibration mount is provided for mounting a first component to a second component. The mount has an elastomeric body which provides a recess into which the first component is received. The mount further has pair of brackets which fit to opposing sides of the elastomeric body sandwiching the first component received in the recess therebetween. At least one of the brackets is arranged to connect the anti-vibration mount and second component together. The mount further has a clamping arrangement which applies clamping pressure across the brackets and thereby compresses the elastomeric body to secure the first component in the recess.

Abstract: The quality of a dry film lubricant coating or molybdenum based undercoat coating provided on the root of a gas turbine fan blade is determined by a method which includes providing an image of the coating taken under controlled conditions which include diffusing light through a translucent screen. The difference between an RGB value of a group of pixels from the image compared with a known RGB value is determined and used to calculate the quality of the coating.

Abstract: A raft assembly for a gas turbine engine is provided. The raft assembly includes a rigid raft formed of a rigid material that has an electrical system and/or a fluid system embedded therein. The raft assembly further includes one or more clamps for mounting tubular members to the raft. The or each clamp has a first clamp block and a second clamp block which, in use, clamp together to grip a tubular member between the blocks. The first block is fixed to the raft. The or each clamp further has a fastener operatively extending between the blocks.

Abstract: The present invention provides a gas turbine engine part which has a primary purpose in the engine which is structural and/or aerodynamic. The part is formed of rigid composite material, and has an electrical system comprising electrical conductors permanently embedded in the composite material. This provides advantages in terms of weight, complexity, and build time.

Abstract: An electrical raft assembly for a gas turbine engine is provided. The raft assembly comprises a rigid electrical raft formed of a rigid material that includes an electrical system comprising electrical conductors embedded in the rigid material. The raft assembly further comprises an engine component that is mounted to the electrical raft.

Abstract: An electrical assembly 600 comprising an electrical raft 200 and an electronic unit 300 is provided to a gas turbine engine 10. The electrical raft 200 has electrical conductors 252 embedded in a rigid material 220, which may be a rigid composite material. The electrical conductors 252 are in electrical contact with the electronic unit 300. When the electronic unit 300 is installed, at least a part 310 of it forms a part of a gas-washed surface of the engine 10. The electronic unit 300 is then easily accessible from the engine 10, and potentially complex and/or heavy access doors/panels may not be required.

Abstract: An electrical raft 200 comprising electrical conductors 252 embedded in a rigid material are provided to a gas turbine engine. The raft 200 is used to transport electrical signals (which may be, for example power and/or control signals) around a gas turbine engine. The electrical raft 200 has an electrical connector 700 embedded therein which is used to connect the electrical raft to an electrical unit, such as an EEC of a gas turbine engine The electrical connector 700 is resiliently biased so as to ensure a reliable electrical connection.

Abstract: The present invention provides a rigid raft formed of rigid composite material. The raft has an electrical system and/or a fluid system embedded therein. The raft further has a tank for containing liquid integrally formed therewith. The tank can be formed of the rigid composite material. The tank can be for a gas turbine engine.

Abstract: A gas turbine engine 10 is provided with rigid raft assemblies 290, which may be electrical harness raft assemblies 290 comprising electrical conductors embedded in a rigid composite material. The rigid raft assemblies 290 can be provided with engine dressings, such as pipework and ECUs to produce an electrical raft assembly. In order to assemble or dress the gas turbine engine 10, the rigid raft assemblies can be pre-prepared to incorporate at least a part of at least one gas turbine engine system/component before being installed on the gas turbine engine 10. During maintenance, whole raft assemblies can be removed and replaced with corresponding, pre-prepared assemblies. This can save considerable time during engine build and maintenance.

Abstract: A gas turbine engine 10 comprises at least one rigid raft assembly that has a fluid passageway 210 at least partially embedded therein. The fluid passageway 210 is at least a part of a fluid system. In addition to the fluid passageway 210, the rigid raft assembly 200 also has at least a part of another system. For example, the rigid raft assembly may also include electrical conductors 252, which are part of an electrical system. The rigid raft assembly 200 may be lighter, easier to assemble, more robust and more compact than conventional solutions for providing systems to gas turbine engines.

Abstract: A gas turbine engine 10 is provided with electrical harness rafts 200 comprising electrical conductors embedded in a rigid composite material. The rafts 200 are used to transport electrical signals (which may be, for example power and/or control signals) around a gas turbine engine. Rafts 200 may be connected together and to other components using flexible cables, that may help to accommodate relative movement of the rafts 200, for example through vibration. The rafts 200 are lighter, more compact, and more convenient to handle than conventional electrical harnesses. The rafts 200 may provide a convenient and secure mounting surface for other components/systems of a gas turbine engine, such as EECs and/or fluid pipes.

Abstract: An electrical raft (200) is provided that has electrical conductors (252) embedded in a rigid material (220). The electrical raft is provided with an electrical connector (700). The electrical connector (700) is mounted in the electrical raft (200) at a mounting angle (730). The mounting angle is set such that the electrical conductors (252) can be connected to the electrical connector without having to turn through an angle or a radius of curvature that would subject them to excessive bending stress. Similarly, the mounting angle means that any conductors (766) that may be connected to the electrical connector (700) do not have to turn through an angle or a radius of curvature that would subject them to excessive bending stress. Furthermore, mounting the electrical connector (700) at the mounting angle (730) may allow the assembled electrical raft (200) to be more compact.

Abstract: A method to detect shaft break includes monitoring first and second parameters and defining a two-dimensional parameter space that is a function of the first and second parameters, the two-dimensional parameter space includes integration regions. The method also includes defining an integration function for each integration region. For measured values of the first and second parameters, the method determines the applicable integration region and applies the integration function to the first parameter to give an integration result; and then sets a shaft break signal to TRUE when the integration result exceeds a predetermined threshold. The present invention also provides a shaft break detection system.

Abstract: An aerofoil blade or vane for the turbine of a gas turbine engine is provided. The blade or vane includes an aerofoil portion which, in use, extends radially across a working gas annulus of the engine. A coolant inlet is formed at an end of the aerofoil portion for the entry of a cooling air flow into the portion. A corresponding coolant exhaust is formed at the trailing edge of the aerofoil portion for spent cooling air to flow from the portion. A passage within the aerofoil portion connects the inlet to the exhaust. A fence within the aerofoil portion extends radially and forwardly from a start position at the end of the aerofoil portion adjacent the trailing edge to an end position. The passage forms a loop which extends along one side of the fence, wraps around the end position, and extends along the other side of the fence.

Abstract: A leaf seal assembly provides a fluidic seal between a first and second member and includes first and second cover plates defining a channel, with a first and second edge, respectively. A plurality of leaf elements are located within the channel, each element having first and second edges adjacent to the first and second cover plates, respectively and a projecting portion of each element extends beyond both edges. A fluid flow in a first direction causes the leaf elements to move away from the first member to create a fluid passage between the elements and the member, allowing a flow through the seal in the first direction; and a fluid flow in a second direction causes the leaf elements to move towards the first member such that a third edge of the projecting portion of each element contacts the member, opposing the flow through the seal in the second direction.

Abstract: A gas turbine engine has, in flow series, a compressor section, a combustor, and a turbine section. The engine further has a cooling system which diverts a cooling air flow received from the compressor section to a heat exchanger and then to the turbine section to cool a component thereof. The cooling air flow by-passes the combustor and is cooled in the heat exchanger. The cooling system has a valve arrangement which regulates the cooling air flow. The engine further has a closed-loop controller which estimates and/or measures one or more temperatures of the cooled component, compares values derived from the estimated and/or measured temperatures with one or more corresponding targets, and issues a demand signal to the valve arrangement based on the comparison and a value of the demand signal at a previous time step.