Abstract: A gas turbine engine is provided with a novel heat exchanger which exchanges heat between the compressor delivery air and turbine exhaust gas. The exchanger comprises a stack of rotary discs angled to produce two sets of wedge-shaped flow areas between them; turbine exhaust gases flow through the discs from one set of areas to the other and heat the discs, while the compressor delivery air flows through a segment of the discs in the reverse direction to exhaust the heat.

Abstract: A coating mixture for use in aluminizing metal surfaces comprises 5 to 50% by weight of an organic resin binder, 2 to 25% by weight of one or more halides and the balance finely divided particles of an aluminium-containing alloy. The alloy has a melting point of at least 1100.degree. C and contains 40 to 60% by weight of aluminium, the balance comprising iron, cobalt, nickel or zirconium or any combination thereof. The coating mixture is applied to the metal surface to be aluminized and then heated in an inert or reducing atmosphere at a temperature of 800.degree. to 1100.degree. C for a time sufficient to enable at least some of the aluminium in the alloy to diffuse into the metal surface.

Abstract: A crucible for melting a nickel-based superalloy containing one or more of the elements aluminium, titanium and hafnium is made of magnesia grains bonded by tinania, hafnia or yttria. The purity of the magnesia is not less than 97%.

Abstract: A ducted fan gas turbine engine comprises a pair of turbines in flow series which are contra-rotating and which drive shafts which in turn drive into an epicyclic gear. The output from the epicyclic gear drives a fan which normally provides forward thrust from the engine. The fan can be made to rotate in the opposite direction to provide reverse thrust by varying the relative speeds of rotation of the two turbines by bleeding working fluid from between them.

Abstract: In a foil gas bearing or other similar machine element the relatively rigid shaft is coated with a glaze-forming oxide layer between 0.003 and 0.020 ins. thick, while the relatively thin foils are coated with a layer of a compound comprising cobalt and chromium carbide to a depth of up to 0.003 ins., the surface layer of which is oxidized to a depth of 0.0001 ins. to 0.0005 ins.

Abstract: An apparatus principally for producing holes in the wall of a passage in a workpiece, the apparatus has a curved tube insertable into the passage and an elongate flexible electrode is fed into the tube and deflected thereby to produce the desired holes, the apparatus is preferably for use with electrical discharge machining power supplies.

Abstract: This invention concerns an apparatus for producing real time and recorded pictures of the internal parts of a gas turbine engine, during the operation of the engine, the pictures being produced by directing high energy X-rays at the engine and deriving the results via a fluorescent screen and an image intensifier.

Abstract: The disclosure of this invention relates to a gas turbine engine combustion chamber including a flame tube having holes closed by a filling of a material of lower melting point than the flame tube material so that if in operation the temperature of the tube exceeds that of the filling the latter melt and cooling air can enter the tube through the holes.

Abstract: An inspection device for inspecting regions of workpieces which are inaccessible to conventional inspection devices. The device comprises a body from which a plurality of abutting members are adapted to extend. The abutting members are interconnected by a tensionable roller chain which is adapted to maintain the abutting members in compression, thereby forming a substantially rigid column which may be provided an inspection probe. The thus formed rigid column may be disposed in angular disposition to the device body.

Abstract: A stator structure for a gas turbine engine comprises abutting segments sealed together at their abutting edges. Each segment comprises a plate spaced from a peripheral surface to form a groove in the edge, and the grooves in abutting edges correspond to form a channel in which a sealing member is positioned.

Abstract: Thermal matching of compounds in a gas turbine engine is achieved by providing the component with the highest rate of thermal expansion with an insulating sheet which is dimpled to contact the surface of the component at discrete spots leaving air spaces in between. The sheet is attached to the component by spot welding at a pre-determined number of areas to provide the necessary heat conducting paths between the insulation and the component to enable the expansion of the component to be matched with that of another component. Seal clearances can be reduced by matching the expansions of seal carrying components in this way.

Abstract: A rotor for a gas turbine engine comprises an outer shell formed in hot pressed silicon nitride and having substantially uniform thickness in a direction parallel to the axis about which the rotor is rotatable and a heat resistant insert which can be either graphite or reaction sintered silicon nitride which fills the space within the shell and is attached to the shell. A row of blades which can be either hot pressed or reaction sintered silicon nitride can be attached to the periphery of the rotor by diffusion bonding.

Abstract: The invention is concerned with apparatus for manufacturing gas turbine engine components e.g. guide vanes and blades, in dense silicon nitride starting with silicon nitride in a powder form.Guide vanes are usually in the form of an aerofoil portion and two shroud portions and according to the invention, the aerofoil portion is made in a first mould by hot pressing a mixture of silicon nitride powder and a fluxing agent, such as magnesia. The formed aerofoil is placed in a second mould so that each end extends partly into a space which is to be filled with a further mixture of silicon nitride powder and a fluxing agent. The further mixtures are hot pressed both to form the shroud portions and to amalgamate the shroud portions with the aerofoil portion.Features, such as, flanges and webs can be formed in the shrouds during the moulding process or they can be machined into the shrouds after the vane is removed from the second mould.

Abstract: A fluid flow duct of a gas turbine engine, the duct being defined between a fan cowl and a centerbody and there being provided movable flexible members attached to the centerbody, each member being movable within the duct by fluid pressure between a first concave position and a second convex position for varying the cross-sectional flow area of the duct.

Abstract: An energy system consists of a gas turbine engine having a power turbine which is arranged to drive a load, the exhaust from the power turbine passes to a further turbine which is arranged to drive a compressor, the exhaust from the further turbine passes to atmosphere via the compressor and a combined cooler and scrubber in which water is heated and sulphur is removed from the hot exhaust gas. The combined cooler and scrubber consists of a bed of flints through which the hot exhaust gas flows and a condenser arranged to receive a supply of relatively cool water, the resulting hot water being stored in a hot water store. The bed of flints also receives a supply of water to which calcium carbonate and manganese sulphate has been added so that sulphur in the form of calcium sulphate is removed from the exhaust gas.

Abstract: A combustion chamber for a gas turbine engine which has staged combustion in two toroidal vortices of opposite hand arranged one upstream of the other. A burner delivers air/fuel mixture in a radial direction to support the vortices and the burner has a convergent outlet for the air/fuel mixture.

Abstract: The disclosure of this invention pertains to a gas turbine engine having an annular combustion chamber having an outlet duct to turbine entry vanes, an extension of the combustion chamber connecting a radially outer wall of the duct to fixed structure at a position adjacent the downstream and of the vanes, wherein the wall is covergent in the downstream direction, the extension is connected to the wall at a location upstream of the downstream extremity thereof, and cooling air passages ae arranged to lead cooling air to the junction so that on heating of chamber in operation said extremity expands radially outwardly and in the downstream direction thereby to make sealing engagement with an adjacent extremity of a shroud ring of the vanes.

Abstract: The invention relates to a shaft coupling assembly wherein two shafts are rotationally located with respect of each other by means of splines provided upon the two shafts. The shafts are located axially by the provision of a further member being provided with similar splines, the third member being adapted to be rotated such that its splines may be brought out of engagement with the other splines to lock them together axially. The third member is rotated by means of a bevel gear arrangement which are rotated by means of an adjusting tool. The arrangement is such that the adjusting tool may only be removed when the third member is in the locked position.

Abstract: A core engine or gas generator for use in a range of gas turbine engines, which consist of a multi-stage compressor and a single stage supersonic turbine, the compressor and turbine being mouned on a single shaft. The compressor includes a number of stages of variable angle and the gas generator has an annular combustion chamber.

Abstract: A gas turbine turbojet engine for a supersonic aircraft which fits into a nacelle having a substantially square cross-section. Air flow passing between the square section of the nacelle and the circular section of the engine is compressed by an auxiliary compressor driven by a compressor of the turbojet. The auxiliary compressor is housed within a diameter not greater than the maximum diameter of the turbojet, thus enhancing the engine performance particularly at take-off.