Abstract: A component such as a turbine blade of a gas turbine engine has a cooling arrangement comprising a cascade impingement array in which cooling air flows from a supply chamber through impingement passages in webs to an internal passageway comprising first and second limbs. The cooling air flow through the limbs, provides improved heat transfer compared with continued impingement cooling in the chordwise direction of the blade.

Abstract: A cooling system is provided for cooling a turbine of a gas turbine engine. The system has first and second flow paths for guiding cooling air received from the compressor of the engine. The routes of both flow paths bypass the combustor of the engine. The system also has a preswirler for receiving the cooling air at the ends of the two flow paths, swirling the cooling air tangentially to the engine axis, and delivering the swirled cooling air to a rotor of the turbine. The first flow path is routed through a heat exchanger which cools the cooling air guided by the first flow path relative to the cooling air guided by the second flow path.

Abstract: A pitch change apparatus is provided for a propeller assembly having a row of propeller blades which rotate around an axis of the assembly. The apparatus has a unison ring which is coaxial with the propeller assembly. The unison ring is movable to drive respective mechanisms for varying the pitch of the blades. The apparatus further has a plurality of pitch lock assemblies circumferentially distributed around the unison ring. Each pitch lock assembly has a free state which allows movement of the unison ring and a locked state which prevents or limits movement of the unison ring and thus prevents or limits variation of the pitch of the blades. The pitch lock assembly moves from the free to the locked state when the assembly receives a signal to lock the blades.

Abstract: A pitch change apparatus comprises a hydraulic actuator for angular displacement of propellers of the propeller assembly. The hydraulic actuator has a piston and cylinder arrangement which defines fine and coarse fluid chambers. Increasing the volume of the fine chamber at the expense of the coarse chamber results in angular displacement of the propellers to a finer pitch. Increasing the volume of the coarse chamber at the expense of the fine chamber results in angular displacement of the propellers to a coarser pitch. The pitch change apparatus further comprises one or more fine hydraulic lines carrying hydraulic fluid to and from the fine chamber, and a coarse hydraulic line carrying hydraulic fluid to and from the coarse chamber. The apparatus further comprises a pressure-sensing check valve which fluidly isolates the coarse chamber from the coarse hydraulic line if the pressure in the coarse hydraulic line falls below a threshold pressure.

Abstract: A back-up featherer is provided for an engine arrangement having a main hydraulic actuator which angularly displaces propellers of a propeller assembly of the engine arrangement. The back-up featherer has a back-up hydraulic actuator for angular displacement of the propellers, the back-up hydraulic actuator rotating with the propeller assembly. The back-up featherer further has one or more back-up fluid supply lines for transferring hydraulic fluid between a hydraulic pressure power source located on a static structure of the engine arrangement and the back-up hydraulic actuator. The back-up featherer further has a back-up hydraulic rotating coupling, the back-up fluid supply lines fluidly communicating with the back-up hydraulic actuator via the back-up rotating coupling. A static side of the back-up hydraulic rotating coupling is mounted to the static structure of the engine arrangement, and a rotating side of the back-up hydraulic rotating coupling rotates with the propeller assembly.

Abstract: A lubrication arrangement for interlocking gears 2, 3 is configured by a housing 1 which incorporates sections 1a, 1b of a snail cross-section. Thus, rotating gears 2, 3 are positioned to generate a centrifugal pumping effect between those gears 2, 3 and the housing sections 1a, 1b which drives scavenged oil flow into a volute 11 formed by the opposing surface of the housing 1a, 1b. The scavenged oil is driven in the direction 13 towards an off-take 12 configured such that there is a minimum available cross-sectional area 14 between the housing at the intermeshing of the gears 2, 3 at an interlocking location 4. In such circumstances the scavenged oil is driven at relatively high speed through the off-take 12. Such relatively high speed scavenged oil 15 can be used for displacement scavenging in other parts of an engine or machine where problems exist with oil residence.

Abstract: Environmental concerns have resulted in consideration of the effects of condensation trails from gas turbine engines. By provision of a condensation stage in a heat exchanger arrangement for a gas turbine engine the level of condensation within a final exhaust gas flow G from an engine is reduced. Furthermore, by cooling of the exhaust gas flows for mixing with by-pass air flows a water partial pressure at an exhaust gas exit temperature can be provided which is below the eutectic liquid to vapor phase transition and therefore avoid condensation (contrail) formation.

Abstract: A blade for a gas turbine engine includes an aerofoil portion and a root portion defined by concave and convex walls having opposing inner surfaces. A reinforcing member is located between the concave and convex walls and is bonded to the inner surfaces of the concave and convex walls, and the root portion includes an unbonded region in which the reinforcing member contacts an inner surface of one of the concave and convex walls but is not bonded to the concave and convex walls.

Abstract: A magnetic gear arrangement is provided having a magnetically active gear member that generates a first magnetic field, which is modulated by interpoles. The modulated magnetic field generates magnetic poles on a magnetically passive gear member, and these poles form a second magnetic field. The material of the passive gear member is sufficiently magnetically hard that the first and second magnetic fields interact to couple the motion of the active and passive gear members according to a given gear ratio.

Abstract: An acoustic assembly for a fan casing of a turbofan engine is made up from acoustic liner panel components which each comprise a body and a backing sheet. The body is an integral injection moulding that generally includes an acoustic structure, a perforated sheet and fastening portions. Adjacent panel components engage each other at non-linear circumferential edges which generally includes lugs on one of the components which are received in recesses of the other component. The lugs are defined by following cell walls over a convoluted path along the circumferential edge.

Abstract: A bleed assembly for a gas turbine engine is provided. The assembly includes: a duct having an inlet and an outlet; a bleed valve that controls the flow of bleed fluid into the inlet; and a dome-shaped diffuser screen which covers the outlet. The diffuser screen has a plurality of through-holes for passage of the bleed fluid. Each through-hole has one or more nearest-neighbour through-holes at a nearest-neighbour spacing. At the periphery of the diffuser screen, the average nearest-neighbour spacing of the through-holes at a given radial distance from the centre of the diffuser screen increases with increasing radial distance.

Abstract: An article has an anodised titanium or titanium alloy surface layer containing pores which form recesses opening to the outside of the layer. A wetting-resistant coating is formed on the anodised surface layer. The coating penetrates the pores but retains the recesses to make the surface of the article hydrophobic and thereby restrict accumulation of ice.

Abstract: An article has a textured surface comprising locally melted, displaced and resolidified material produced by relative movement of a power beam over the surface. The article further has a wetting-resistant coating formed on the textured surface to make the surface hydrophobic and thereby restrict accumulation of ice.

Abstract: An annulus filler assembly for a rotor of a turbomachine, the assembly comprising: an annulus lid (56) having a radially outwardly facing surface (58) for forming an inner wall of a flow annulus of the rotor and a radially inwardly facing surface; and a frame for supporting the annulus lid (40), the frame being mountable to a disc of the rotor such that the annulus lid (56) is spaced away from the disc, wherein the frame (40) comprises a connection portion (46) which, in use, passes through an aperture (60) in the annulus lid (56) from the radially inwardly facing surface towards the radially outwardly facing surface (58) such that at least a portion of the connection portion (46) is visible from the radially outwardly facing surface (58); the assembly further comprising a locking element (68) which locks the connection portion (46) to the annulus lid (56) via the visible portion of the connection portion (46).

Abstract: The present invention relates to a bearing assembly (1) for a rotatable shaft (2). The bearing assembly comprises a bearing housing (10); a bearing (20) located within the bearing housing (10) and arranged in use to receive a rotatable shaft (2); and a damper (14) that couples the bearing (20) to the bearing housing (10) for damping vibrations of the rotatable shaft (2). The damper (14) comprises a shape memory alloy (40). This arrangement allows the bearing assembly to damp vibrations of the rotatable shaft.

Abstract: The present invention relates to a bearing assembly (1) for a rotatable shaft (2). The bearing assembly comprises a bearing housing (10); a bearing (20) located within the bearing housing (10) and arranged in use to receive a rotatable shaft (2); and an elongate member (14) that couples the bearing (20) to the bearing housing (10) for damping vibrations of the rotatable shaft (2). The elongate member (14) comprises a piezoelectric element (40) which may be actuated so as to exert a force on the elongate member. This arrangement allows the bearing assembly to damp vibrations of the rotatable shaft.

Abstract: A leaf seal assembly (20) for providing a seal between a first member and a second member (10), the leaf seal assembly comprising a plurality of leaf elements (22) and a first substantially planar cover plate (24a), the leaf elements being arranged in a pack, with a first edge of each leaf element being adjacent to the first cover plate, wherein each leaf element comprises a first shoulder (30a) in the first edge, the first shoulder being arranged so as to form a first gap (28a) between the first edge of each leaf element and the first cover plate over a portion of the first edge.

Abstract: A component is manufactured from a powdered material such as a titanium alloy, by performing a first hot isostatic pressing HIP operation on the powdered material 14 while the powdered material is in contact with a moulding surface 8 of a rigid, usable moulding tool 2. The first HIP operation creates a non-porous shaped surface 16 on a partially consolidated component 14, but avoids bonding or reaction between the partially consolidated component 14 and the moulding tool 2. After separation of the partially consolidated component 14 from the moulding tool 2, the partially consolidated component 14 is subjected to a second HIP operation in which the powdered material is fully consolidated.

Abstract: A method of forming a cast product by providing a core having a plurality of sections and one or more gaps there-between. The core further comprises an insert member spanning the gap between adjacent sections. The core is located within a mould and a liquid phase material is introduced into gap between the core sections. The liquid phase material is solidified in the gap so as to form a cast feature of a resulting solid product and the core sections are removed from the solid product such that the insert member remains securely held within the feature.

Abstract: An engine arrangement has a gear assembly that drives a first propeller assembly. The gear assembly is driven by a power drive shaft that joins to the gear assembly at a first side. The engine arrangement has a static conduit that extends along a longitudinal internal cavity of the power drive shaft. The conduit penetrates the gear assembly such that a portion of the conduit projects from an opposing second side of the gear assembly. The engine arrangement has one or more first fluid supply lines routed along the static conduit between a hydraulic pressure power source and the first hydraulic actuator. A first hydraulic rotating coupling is mounted to the projecting portion of the static conduit. The first fluid supply lines fluidly communicate with the first hydraulic actuator via the first rotating coupling.