Abstract: A wall arrangement for the main gas path of a gas turbine engine, including: a wall segment which defines the main gas path, the wall segment having a gas path side, an outboard side and a support wall extending from the outboard side towards a supporting structure, and a channel member abutting the support wall and having one or more channels defined by the abutment of the support wall and channel member, the one or more channel having radially separated inlet and outlet.

Abstract: A method including the steps of: defining an original parent polygon representative domain of interest, an origin corresponding to a wavesource position within the parent, a wavesource wavefront geometry, and a maximum wavefront extent; determining one or more valid parent polygon sides; defining cutting lines from the vertices of each valid parent side to the extent; reflecting the parent about the respective valid side defining a child polygon; discarding portions of each child polygon lying beyond a cutting line from the respective parent side; redefining each child as a parent, and repeating the second to fifth steps for each parent filling the area within the extent; projecting onto the polygons within the extent, a wavefront having the wavefront geometry spaced from the origin by a specified distance; and reflecting the child polygons along the respective sides of their respective parents projecting the child polygons and wavefront onto the original parent.

Abstract: A fluidfoil comprises a main body and a fence, wherein the fence has different lean angles with respect to the main body at different chordwise positions, and wherein the fence is divided along its chordwise extent into at least two portions, where a first portion nearer a leading edge of the fence has a smaller lean angle than a second portion further from the leading edge, and wherein all portions are either anhedral or dihedral.

Abstract: A hydraulic seal arrangement for a rotating machine, the hydraulic seal arrangement comprising: an annular housing around a shaft having an axis of rotation, the shaft and the annular housing being relatively rotatable; the annular housing further comprising a sealing fluid zone at a radially outer portion of the housing; a fin extending radially from the shaft into the annular housing, at least a portion of the fin extending radially into the sealing fluid zone; wherein sealing fluid is centrifugally accelerated, in use, before being directly introduced into the sealing fluid zone by a sealing fluid inlet, to generate a swirl component upon introduction.

Abstract: A turbofan engine comprises a nacelle and an engine core having a core cowling. The internal surface of the nacelle and the external surface of the core cowling define a bypass duct having an exhaust end defining a bypass duct exit plane generally normal to the longitudinal axis of the engine. The core cowling extends aft of the bypass duct exit plane and has an annular or partly-annular exit ventilation nozzle located aft of a first longitudinal position and fore of a second longitudinal position, the first and second longitudinal positions being respectively fore of and either aft of or coincident with the bypass duct exit plane, the core cowling otherwise being free of exit ventilation nozzles fore of the second longitudinal position. The engine has a lower specific fuel consumption than an equivalent engine having an exit ventilation nozzle in a conventional position aft of the second longitudinal position.

Abstract: Combustion equipment includes annular combustion chamber having an annular upstream wall structure. Annular outer casing surrounds and is spaced from annular combustion chamber and annular inner casing is within and spaced from annular combustion chamber. Ogee shaped annular cowl is positioned upstream of annular upstream wall structure and a stage of compressor outlet guide vanes is positioned upstream of annular cowl. Pre-diffuser extends in downstream direction from stage of compressor outlet guide vanes, pre-diffuser is positioned upstream of cowl. Stage of compressor outlet guide vanes is connected to outer and inner casing. Outer fairing extends radially inwardly from outer casing such that annular outer casing, outer fairing and pre-diffuser define annular outer cavity and outer fairing is spaced from cowl or inner fairing extends radially outwardly from inner casing such that annular inner casing, inner fairing and pre-diffuser define an annular inner cavity and inner fairing is spaced from cowl.

Abstract: An electric motor generator system has a hollow rotatable shaft, a coil spar, and a plurality of magnet portions. The hollow rotatable shaft has a central longitudinal axis. The coil spar comprises one or more coil assemblies and is positioned concentrically within the hollow rotatable shaft. Each of the magnet portions is shaped to conform to a radially inwardly facing surface of the shaft. Each of the plurality of magnet portions abuts conformally against the radially inwardly facing surface of the shaft between the radially inwardly facing surface and the or each coil assembly.

Abstract: A method of controlling a reciprocating internal combustion engine comprising: a cylinder defining a cavity having a first end and a second end; and a piston moveable within the cavity of the cylinder between the first end and the second end, the method comprising: controlling injection of a quantity of liquid air, without fuel, into the first end of the cavity at a first time when the piston is closer to the first end than the second end to cause the piston to perform a first power stroke; and controlling injection of fuel into the first end of the cavity at a second time when the piston is closer to the first end than the second end to cause the piston to perform a second power stroke.

Abstract: A method of controlling a reciprocating internal combustion engine comprising: a cylinder defining a cavity having a first end and a second end; and a piston moveable within the cavity of the cylinder between the first end and the second end, the method comprising: receiving at least a first signal; determining a quantity of liquid air to be injected using at least the received first signal; controlling injection of the determined quantity of liquid air into the first end of the cavity at a first time when the piston is closer to the first end than the second end.

Abstract: A procedure defining a balancing strategy includes: providing a computer model which predicts the vibration amplitude at a given axial position along the spool when the spool is rotated at a given rotational speed; using the model to predict respective vibration amplitudes at the given axial position for different axial positions of a unit unbalance applied to the spool; plotting the predicted vibration amplitudes as data points on a graph of vibration amplitude against axial position of the applied unit unbalance; using the graph to identify axial positions which are more or less likely to contribute to flexing of the spool at the given rotational speed when mass is added or removed from the first rotor module to reduce imbalances at the axial positions; and defining a balancing strategy based on the identification.

Abstract: A nickel-base superalloy that includes 6.55% to 7.15% aluminum, 3.3% to 3.7% titanium, 1.2% to 1.7% tantalum, and 0.8% to 1.0% niobium, such that a combined atomic percentage of the aluminum, the titanium, the tantalum and the niobium is between 12.65% and 13.15% to provide substantially 51% to 53% by volume of gamma prime precipitates.

Abstract: A method of detecting a fault in an induction machine having one or more windings arranged to draw current at a supply frequency, the method including: performing a process of judging whether a respective sideband of one or more selected harmonics of the supply frequency exists at a predetermined fault frequency in a signal in the one or more windings; and determining that a fault has occurred if the judgement is positive; wherein in the judging process each of the selected harmonics of the supply frequency is a harmonic frequency of the supply frequency other than the supply frequency itself.

Abstract: A fuel conditioning apparatus for de-oxygenating a liquid hydrocarbon fuel has a catalyst portion which, in turn, has an inlet portion and an outlet portion. A hydrocarbon fuel stream is fed through the inlet portion and into the catalyst portion where it passes over a catalytically active component. The catalytically active component promotes the reaction of the fuel with the dissolved oxygen in the fuel stream, converting it into less chemically reactive forms and thereby reducing the fuel's propensity to form carbonaceous deposits.

Abstract: A turbine stator vane assembly comprises a plurality of circumferentially arranged struts and a plurality of circumferentially arranged stator vanes. Each stator vane has a leading edge, a trailing edge and a chord length. Each strut has a leading edge, a trailing edge, a chord length, a pressure surface and a suction surface. The chord length of the struts is greater than the chord length of the stator vanes. The stator vanes are arranged in groups between adjacent pairs of struts and each group of stator vanes comprises a plurality of stator vanes. The circumferential spacing between adjacent struts is substantially the same and each stator vane in a group of stator vanes has a different chord length to the other stator vanes in that group of stator vanes.

Abstract: A pressure relief arrangement for a gas turbine engine comprises a hinged door and a mount. A plastically deformable member is provided between and coupled to the hinged door and the mount. The deformable member is configured to deform between a non-deformed state when the door is in a closed position and an elongated deformed state when the door is in an open position.

Abstract: This invention concerns a flow seal (42) for location between opposing components of a fluid flow machine, such as rotor (44) and stator (46) components of a turbomachine (10). The seal (42) has an upstream fin (24) depending from one of components (44) towards an opposing surface (28) of the other (46) of the components and a wall (26) downstream of the fin (24) defining a flow cavity between the fin (24) and wall (26). The fin (24) terminates at a fin tip (24A) so as to define a gap between the fin tip (24A) and the opposing surface (28), through which a leakage flow enters the flow cavity in use. The seal (42) also has a flow guide member (30A) located in the cavity, the flow guide member (30A) being arranged to define a flow path that promotes a vortical flow regime in the cavity. The flow cavity geometry is altered to promote a desired vortical flow regime, such as by way of a projection (39) in an intermediate wall portion of the flow cavity. The vortical flow regime may hinder flow leakage.

Abstract: An intake (12) for a gas turbine engine (10) has an annular lip structure (23) extending about a central axis (11) and defining an intake opening. The annular lip structure (23) has a leading edge (38) located between a radially inwardly facing portion of the intake and a radially outwardly facing portion of the intake (12). The annular lip structure (23) has upper, lower and opposing side regions on either side of the central axis (11). The annular lip structure (23) comprises a formation (40; 42; 48) on the radially inwardly facing portion arranged to create a non-symmetric flow field over the opposing side regions of the annular lip structure (23). The formation (40; 42; 48) may be actively controlled in response to ground vortex conditions.

Abstract: There is disclosed a variable vane actuation arrangement 100, 200 comprising a crankshaft 48, 148 comprising a crank web 50,150 and a unison ring assembly 45 comprising a unison ring 34 moveable to vary the pitch of a plurality of variable vanes 26. A connector 42 is fixed with respect to the unison ring 34. The crank web 50, 150 and the connector 42 cooperate by a pin 56—slot 52, 152 mechanism configured so that rotation of the crankshaft 48, 148 causes rotation of the unison ring 34. There is further disclosed a gas turbine engine with a variable vane actuation arrangement.

Abstract: Apparatus to enable rotation of a compressor, the apparatus comprising: a guide for insertion through a fan of a gas turbine engine to the compressor, the guide including: a surface arranged to guide a drive assembly through an interior portion of the gas turbine engine to the compressor; and a first fastener arranged to fasten the guide to the gas turbine engine.

Abstract: An aircraft propulsion system in which a combustion engine is arranged to drive an electrical generator. An electrical energy store is provided within the system. A propulsive rotor is arranged to be driven by an electric motor and a controller selectively varies the supply of power to the electric motor from the generator and/or energy store in dependence on one or more property of a vapor trail resulting from the engine exhaust flow. The controller may also control the supply of power to the energy store for charging.