Abstract: A variable stator vane operating mechanism for a gas turbine engine includes a plurality of unison rings 21,22 and 23 each connected by a drag link 18,19 and 20 respectively to a pivoting beam 14. The unison rings are connected to each of vanes 10 in a stator vane row by first arms 24. In order to minimize side loads on the unison rings by the drag links during pivoting of the beam, the beam is connected at its free end to a second arm 30 which is pivotable about an axis 28 by means of a torque tube 26 or other suitable actuator, and the length of the second arm 30 between the axis 28 and its point of connection 44 to the beam is made as nearly as possible equal to the length of the first arms 24. By this means the fore and aft movement of the beam can be matched to the fore and aft movement of the unison rings, or at least in the case of one of them, and the drag links remain substantially in the plane of the unison rings.

Abstract: A turbine suitable for a gas turbine engine is provided with a bearing support member which is interconnected with the turbine casing by means of an annular array of aerofoil guide vanes. The whole assembly of support member and aerofoil guide vanes is maintained in a state of tension. The degree of tension in the assembly is controlled so as to be substantially constant throughout the normal operating cycle of the turbine.

Abstract: 1. Combustion apparatus comprising a duct for containing a flow of air and including an air-fuel mixing device comprising an assembly of transversely spaced longeron members which extend along the duct and are inclined to the general direction of flow through the duct and to the walls of the duct so that a major portion of the flow through the duct will pass through the spaces between the longeron members, each longeron member having longitudinal edges adapted in operation to shed continuous vortices and a baffle extending across the upstream end of the longeron members and forming behind it a sheltered pilot combustion zone, and means adapted to generate pilot vortices of combustible mixture in the pilot zone, to cause each pilot vortex to divide, and to direct the divided portion of each pilot vortex to pass downstream along adjacent parts respectively of adjacent longeron members.

Abstract: A core or core part for use in the lost wax casting process is strengthened by admixture to its material of a proportion of short reinforcing fibres.

Abstract: A dual fuel burner for a gas turbine engine comprises a gas fuel manifold and ducts opening into a central air passage, a liquid fuel manifold and tangentially arranged apertures opening into an annular liquid fuel passage terminating in an annular nozzle. The central air passage has an upstream swirler, and is arranged to receive a flow of compressed air at its upstream end and to discharge a flow of compressed air and either gaseous or liquid fuel from its downstream end. The burner also has a water manifold so that water can be injected into the fuel and air flow via ducts and an annular air passage, to control NOx emission.In an alternative arrangement, the liquid fuel can be injected into the annular air passage.The burner is intended to operate on a range of high calorific fuels, both liquid and gaseous, and is designed to minimize the surface area on which carbon may accumulate during operation.

Abstract: In a non-contacting gas seal for a gas turbine engine a seal ring (12) (FIG. 3) is formed from a ring of overlapping segments (16) mounted in a housing (14) on a static component (9) of the engine, and co-operating to define a sealing face (15) which confronts a sealing face (10) on a rotating component (8) to form a seal. The segments overlap and are spaced at their leading ends from the rotating component to define a tapering gap (19) therebetween so that they lift away from the rotating component in operation to ride on a gas film leaving only a very small clearance.In order to ensure that the relative circumferential dispositions of the segments does not alter significantly due to eccentric movements of the rotating component in operation, a dogged ring (34) is provided which is located in the housing by an anti-rotation dog (38) and has spaced dogs (36) engaging each of the segments to prevent circumferential movement thereof while allowing limited radial movement.

Abstract: A gas turbine engine and its associated air intake system in which the air intake system comprises a generally horizontally extending duct through which an airflow is induced by an ejector pump powered by the engine. A portion of the air passing through the duct is directed through a second duct to the air inlet of the engine. The second duct is connected to the first duct in such a manner that the air directed to the engine air inlet is derived from a vertically upper region of the first duct. The arrangement is intended to reduce the amount of airborne particulate material ingested by the gas turbine engine.

Abstract: A containment ring for a gas turbine engine consists of a substantially rigid inner cylinder around the periphery of which is wound layers of fibrous material, a plurality of axially extending strips are located upon the outermost curved surface of the layers of fibrous material and are secured thereto by self-tapping screws.

Abstract: A stator assembly for a turbomachine having a sealing plate which co-operates with sealing members on an adjacent rotor assembly to form air seals. The sealing plate is provided with a thermal slugging mass, the thermal response of which controls the rate of expansion and contraction of the sealing plate to match that of the rotor. In this way tip clearances between the stationary and rotating parts of the air seals are maintained substantially uniform throughout all operating conditions of the turbomachine.

Abstract: A fluid processing device for use in the oil system of gas turbine or other plant, performs the functions of a de-gassifier and filter for liquid from part of the plant, scavenge pump for returning clean liquid to the plant, air/liquid droplet separator and main pressure pump, or any required combination of these functions. The performances of individual rotary devices are enhanced by the inclusion of a quantity of a rigid porous material having interconnected interstitial passages so that all the rotary devices can operate at the same speed and can thus be driven from a single shaft.In a gas turbine engine application (FIG. 3) the device has a plurality of individual compartments 36,38,40 and 41 within a rotating housing 21, each compartment containing the porous material. Compartments 36 and 38 are supplied with air and emulsified oil via pipes 44 from bearing chambers.

Abstract: An aerofoil member such as a blade or vane for a gas turbine engine comprises a hollow aerofoil with a plug of porous material filling a region of the hollow interior. The porous material forms at least part of the external surface of the aerofoil so that cooling fluid can flow from the interior of the aerofoil through the plug to the external surface of the aerofoil. The plug is preferably at the leading or trailing edge of the aerofoil. Methods of making the member include investment casting using a porous ceramic core to form the porous plug, or using sintered particulate material to form the porous plug.

Abstract: A blade or vane structure for a gas turbine engine comprises a hollow aerofoil member and a cooling air entry tube within the hollow aerofoil member, the aerofoil and the tube comprising a unitary cast structure. To make this structure it is proposed that a lost wax casting process should be utilized, with the internal cavities formed using ceramic cores formed with the aid of temporary, disposable pieces which define the space eventually occupied by the tube.

Abstract: A gas turbine engine has a turbine which includes an annular array of rotary aerofoil blades surrounded by an annular shroud member. All or a major portion of the annular shroud member is constituted by a heat pipe. A distance measuring device is provided to measure the clearance between the tips of the rotary aerofoil blades and the shroud member and its output is monitored by a control unit. The control unit is adapted to control a valve which regulates the flow rate of cooling air directed onto the heat pipe. The arrangement is such that the temperature of the heat pipe is maintained at a level which is consistent with the clearance between the rotary aerofoil blade tips and the annular shroud member being within a predetermined range of values.

Abstract: A modular gas turbine engine comprises a gas generator module and a power turbine module. The shafts carried within each module are mounted on bearings which are arranged such that the downstream bearing of the gas generator module and all of the bearings of the power turbine module are contained within a common chamber which is defined by portions of both the gas generator module and the power turbine module.

Abstract: A method of making a two part aerofoil gas turbine engine blade consisting of casting each individual part separately, the parts being cast by the lost wax process, and subsequently joining the parts together after machining.

Abstract: In casting of hollow turbine blades problems arise with breakage or distortion of long thin cores for small diameter cooling passages, and also in maintaining cores accurately positioned for casting thin walled blades. The present invention provides a method of manufacture in which a pre-form of the blade, or other hollow article, is made in two parts and is accurately machined to define the required passage shapes or wall thicknesses in at least one of the parts, appropriate cores are made and the pre-form parts are assembled in a casting mould with the cores in position and heated to melt the preforms. Thus the cores are supported by solid material during the melting process. The melting can take place progressively in a uni-directional manner along the article so that only a narrow area of the article becomes melted at any time and the cores are supported in the melt from both ends. Thus columnar grained or single crystal articles can be made by this method.

Abstract: A method of treating a titanium or titanium base alloy surface prior to the electroplating of a metal thereon in which the surface is immersed in a solution containing hydrofluoric acid, ammonium bifluoride and dimethylformamide. Reaction between the solution and the surface results in a coating being deposited on the surface which provides better adhesion between the surface and any metal subsequently electroplated thereon.

Abstract: A gas turbine engine is provided with an annular sealing element which is adapted to provide a gas seal between relatively rotatable gas turbine components. The sealing element is in the form of a woven fabric which has metallic warp filaments, metallic weft filaments and metallic warp pile filaments. The free ends of the warp pile filaments are non-looped. The sealing element is brazed to one of the gas turbine engine components so that the free ends of the warp pile filaments abut the other gas turbine engine component in sealing engagement.

Abstract: A turbine suitable for a gas turbine engine is provided with a stage of rotary aerofoil blades which is surrounded by a shroud ring made of silicon nitride. In order to minimize load transfer between the shroud ring and the turbine casing the shroud ring is radially supported by and radially spaced apart from the turbine casing by an annular brush seal.

Abstract: A device for priming an empty or partially full burner manifold of a gas turbine engine with fuel before it is required to supply from the burner manifold to the associated burners comprises a fuel accumulator and a control valve.A fuel pressure signal supplied to the control valve terminates the supply of relatively high pressure fuel to the fuel accumulator via the control valve. A metered quantity of fuel is supplied via the control valve to the burner manifold from the fuel accumulator by the motive force of a spring acting on a piston in the accumulator. The metered quantity of fuel is supplied via the control valve to the burner manifold, to fill the burner manifold and to prevent undesireable drops in the quantity of fuel being supplied to other manifolds when the regulated fuel is supplied to the burner manifold.