Abstract: An engine arrangement (10) comprises propulsion means for propelling the aircraft (12), and drive means to drive the propulsion means. The arrangement (10) further includes mounting means to mount at least the propulsion means in a location spaced above the upper surface of the aircraft (10). In the preferred embodiment, the propulsion means is in the form of tip driven fans (14), and the drive means comprises gas generators (34) mounted within the body of the aircraft (10) fixedly connected by intake ducts (36) to the underside of the aircraft (10).

Abstract: A gas turbine engine fan blade containment assembly (38) comprising a generally cylindrical, or frustoconical, metal casing (40) which has an inner surface (62), an outer surface (64), an upstream flange (42) and a downstream flange (52). The outer surface (62) of the metal casing (40) is provided with a pattern of blind apertures (66) which extend radially inwardly from the outer surface (62) of the metal casing (40) between the flanges (42,52). The fan blade containment has reduced weight of the metal casing (40) of the fan blade containment assembly (38) for a large diameter turbofan gas turbine engine (10) but has unimpaired stiffness and penetration resistance.

Abstract: A control arrangement (34) for controlling the size of a gap (30) between first and second components. The control arrangement comprises first magnet means (38) to be provided on the first component, and second magnet means to be provided on the second component. The first and second magnet means are in magnetic interaction with each other across the gap (30) and the arrangement further includes control means (36) to control the size of the gap (30) the first magnet means (38) is a moveable in a first direction to cause the control means (36) to effect relative movement of the first and second components to increase the gap (30) and in a second direction to cause the control means (36) to effect relative movement of the first and second components to decrease the gap (30).

Abstract: A turbine blade for a gas turbine engine comprises an aerofoil having a suction and pressure side. The pressure side is provided with a reflex curvature at the aerofoil trailing edge region so as to reduce the thickness of the aerofoil in that region.

Abstract: An air cooled component with an internal air cooling system comprising an internal cavity which is divided into at least two compartments. The compartments are arranged in flow sequence by communication through side wall chambers formed in the wall of the component. At least one of the side wall chambers is sub-divided into a plurality of cells in flow parallel and each of the cells has at least one air entry aperture and at least one air exit aperture.

Abstract: A method of adding boron to a tungsten, or tantalum, containing titanium aluminide alloy to form a boride dispersion in the tungsten, or tantalum, containing titanium aluminide. A molten tungsten, or tantalum, containing titanium aluminide alloy is formed and tungsten, or tantalum, boride is added to the molten tungsten, or tantalum, containing titanium aluminide alloy to form a molten mixture. The molten mixture is cooled and solidified to form a tungsten, or tantalum, containing titanium aluminide alloy having a uniform dispersion of tungsten, or tantalum, boride particles substantially without the formation of clusters of tungsten, or tantalum, boride. The titanium aluminide alloy comprises between 0.5 at % and 2.0 at % boron.

Abstract: A three-stage lean burn combustion chamber (28) comprises a primary combustion zone (36), a secondary combustion zone (40) and a tertiary combustion zone (44). Each of the combustion zones (36,40,44) is supplied with premixed fuel and air by respective fuel and air mixing ducts (54,70,92). The fuel and air mixing ducts (54,70,92) have a plurality of air injections apertures (62,64,76,98) spaced apart in the direction of flow through the fuel and air mixing ducts (54,70,92). The apertures (62,64,76,98) reduce the magnitude of the fluctuations in the fuel to air ratio of the fuel and air mixture supplied into the at least one combustion zone (36,40,44). This reduces the generation of harmful vibrations in the combustion chamber (28).

Abstract: A combustor for a gas turbine engine comprising at least one combustor air intake chute wherein at least one of the air intake chutes is configured to enhance the heat transfer relationship between the chute material and the air flowing over it. The air intake chutes have at least one raised feature formed on their inner surface which extends into the airflow passing through the chute. The raised features may take the form of a circumferential rib, an axial rib or a pedestal, or any combination of the same.

Abstract: A disk for a BLISK rotary stage of a gas turbine engine includes a stub on the tapered circumferential surface of a turbine disk, the stub defining a weld joint surface on the radially outermost face of the stub. The weld joint surface follows the annulus curvature in axial and circumferential directions while remaining flat in a third direction. A blade is applied radially to the stub and linear friction welding of the blade to the stub is effected by oscillating the blade in said third direction while applying a welding force inwardly along the blade.

Abstract: A gas turbine engine fan blade (26) comprises a root portion (36) and an aerofoil portion (32). The aerofoil portion (32) has a convex surface (44), a concave surface (42), a leading edge (38) and a trailing edge (40). The leading edge (38) of the aerofoil portion (32) is formed from a harder material than the regions of the concave surface (42) and convex surface (44) immediately adjacent the leading edge (38) such that the leading edge (38) of the aerofoil portion (32) remains pointed. This improves the efficiency of the fan blade (26) and hence the gas turbine engine (10) and reduces flutter of the fan blade (10).

Abstract: A component for a gas turbine engine having at least one surface, that has been treated by ultrasonic hammer peening so as to provide a region of deep compressive residual stress in the treated region.

Abstract: A three stage lean burn combustion chamber (28) comprises a primary combustion zone (36), a secondary combustion zone (40) and a tertiary combustion zone (44). Each of the combustion zones (36, 40, 44) is supplied with premixed fuel and air by respective fuel and air mixing ducts (76, 78, 80, 92). Secondary fuel injectors (106) and two secondary fuel manifolds (105A, 105B) supply fuel into different circumferential sectors, halves, of the secondary fuel and air mixing duct (80). The secondary fuel manifolds (105A, 105B) have secondary fuel valves (107A, 107B) which supply a greater proportion of fuel to the secondary fuel manifold (105A) than the secondary fuel manifold (105B) so that there is circumferential biasing of fuel in the secondary combustion zone (40). This circumferential biasing of fuel in the secondary combustion zone (40) reduces the generation of harmful pressure oscillations in the combustion chamber (28).

Abstract: A breather outlet 10 for discharging a liquid dispersion therefrom comprising an outlet pipe 12 wherein the breather outlet 10 further comprises an electromagnetic wave generator 14 so that, in use, electromagnetic waves produced by the wave generator 14 impart sufficient electromagnetic energy to the liquid dispersion to evaporate at least a portion thereof.

Abstract: A seal (30) is provided for reducing the gap between alternate wall members (20) and adjacent blades (14) that are arranged circumferentially in a rotor (12). The seal (30) has a flange portion (36), which is inclined radially inward. The flange portion (36) of the seal (30) is in the form of rubber bellows (32) which have a cavity (34) therein. In operation the flange portion (36) of the seal (30) is deflected radially outwards by centrifugal forces acting thereon. The seal (30) is open at one end to allow air compressed by the rotor (12) to pass into the cavity (34) and inflate the seal (30). Inflation of the seal (30) ensures that the gap between the edge (26) of the wall member (20) and the blade (14) is filled. A good seal is thus maintained throughout operation of the rotor (12) and prevents the air in void (28) passing into the blade passage.

Abstract: Tip treatment bars 16 of a rotor casing 2 for a gas turbine engine are subjected to a process which induces compressive stress within the bars 16. The process may be a laser shock peening process applied to opposite sides 20 of each bar 16. The processing of the tip treatment bars 16 renders them less susceptible to fatigue failure.

Abstract: Use of an optical fiber for the direct receipt of heat radiation for transmission to a remote pyrometer is enabled by the provision of an apertured, contaminant free compartment in the component being heated, and aligning the heat receiving end of the optical fiber with the aperture so as to receive radiated heat from within the compartment.

Abstract: Two stages of relatively rotatable guide vanes (22,24) are arranged in tandem. Shroud portions (42,46) on the vanes overlap in loose engagement, until an associated gas turbine engine starts operating. Gas loads then act on the downstream vane stage (24) and move it in a downstream direction until the opposing flanks of radially opposing lands (44,48) on respective shrouds (42,46) engage, whereupon, gas leakage via the overlap onto the turbine casing (40) is at least substantially reduced.

Abstract: A fuel delivery system for a gas turbine engine combustor, the combustor having at least two fuel injectors of substantially the same design. All the fuel injectors are in flow communication with a first fuel supply via a first manifold, and some but not all of the injectors are in flow communication with a second fuel supply via a second manifold. During normal operation of the gas turbine engine combustor fuel is supplied to all of the fuel injectors via the first manifold. However, during predetermined engine operating conditions a second fuel supply is used to supply fuel flow in those fuel injectors in flow communication with the second manifold.

Abstract: A turbine assembly for a gas turbine engine includes a plurality of turbine blades (32) mounted on a rotatable support means in the form of a turbine disc so as to extend radially therefrom. The turbine blades include circumferentially extending blade platforms (40) spaced from the turbine disc and means are provided for allowing the passage of air between an internal region of the blades (32) and a space located between the blade platforms (40) and the turbine disc. The air may flow out of and back into the same turbine blade, or may flow into an adjacent blade. This flow of air results in the cooling of the blade platforms (40).

Abstract: A method of manufacturing a ceramic matrix composite comprises forming a slurry comprising a ceramic sol, filler particles and a solvent and forming laminates of fibres (12). The laminates of fibres (12) are impregnated with the slurry and are stacked (14) on a mould (10). The stack (14) of laminates of fibres (12) is covered by a porous membrane (16), a breather fabric (18) and a vacuum bag (20). The vacuum bag (20) is evacuated and is heated to a temperature of 60° C. for 10 hours to produce a ceramic matrix composite. The ceramic matrix composite is then heated to a temperature of 1200° C. at atmospheric pressure to sinter the ceramic matrix composite.