Abstract: A method is provided of determining the internal cross-sectional area of a pipe along its length. The method includes the steps of: (a) filling the pipe with a first fluid; (b) feeding a second fluid into the pipe at a known flow rate, a meniscus being formed between the first and the second fluid, and the meniscus moving along the pipe as the second fluid displaces the first fluid in the pipe; (c) ultrasonically detecting the position of the meniscus as it moves along the pipe; and (d) determining from the second fluid flow rate and the meniscus position, the internal cross-sectional area of the pipe along its length.

Abstract: A heat transfer arrangement for a fluid-washed body having first and second ends and a fluid-washed surface extending there-between. The arrangement includes a heat transfer member extending from the first end at least part way along the body towards the second end. A heat source is arranged in use to heat the heat transfer member in the vicinity of the first end of the body. A plurality of thermal control layers are provided on the heat transfer member, each of the layers having a different thermal conductivity and being juxtaposed so as to create a thermal conductivity profile which varies along the length of the member. The arrangement may be used for prevention of icing of an aerofoil body such as a blade, vane or the like.

Abstract: A bearing arrangement is disclosed. The bearing arrangement includes first and second bearings, with each bearing including a respective support element and a respective set of rolling elements and defining a respective load path extending through the respective support element and rolling elements. The support elements are coupled such that a load applied to either support element is transmitted through both the first and second load paths. The arrangement further includes a pair of superelastic titanium alloy elements located in the respective load paths to provide resilient movement between the bearings when a load is applied to the bearing arrangement.

Abstract: An additive layer manufacturing method includes the steps of: a) laying down powder layer on powder bed, and b) focussing energy on an area of powder layer to fuse area of powder layer and thereby form a cross-section of the product; wherein steps a) and b) are repeated to form successive cross-sections of product, and wherein at least one of said steps b) involves focussing energy on an area of respective powder layer which is unsupported by a previously formed cross-section of product to thereby form a downwardly facing surface of product. Method is at least some of said successive steps b) involve focussing energy on a support area of respective powder layer, to fuse support area and thereby form successive cross-sections of a support pin within powder bed, support pin extending outwardly from downwardly facing surface of product when it is formed, so as to support downwardly facing surface.

Abstract: A panel attachment system comprises a panel and a casing. The panel has one fixed mount bracket, and at least one sliding mount bracket. The casing has one fixed mount boss, and at least one sliding mount boss. When the panel attachment system is in use, the fixed mount bracket is fixedly secured to the fixed mount boss, and the or each sliding mount bracket is slidingly engaged with a corresponding respective one of the or each sliding mount boss. This enables the panel to be detachably connected to the casing, such that any relative in-plane thermal expansion between the panel and the casing is accommodated by corresponding relative movement between the one or more sliding mount brackets and the corresponding one or more sliding mount bosses.

Abstract: A fuel injector comprises a plurality of swirler vane passages defined between swirler vanes. Each vane is leant with respect to the true radius of the swirler. The pressure distribution through the swirler passages is improved and the flow of air over a prefilmer located at the radially outer edges of the swirl vanes is improved and consequently atomization of fuel is improved and levels of NOx is reduced.

Abstract: A method of inspecting a component in an assembled gas turbine engine includes inserting a boroscope and a conduit through an aperture in a casing of the engine. The conduit has an applicator tip. The boroscope and conduit are directed to the component to be inspected. A dye penetrant is supplied through the conduit to the applicator tip. The applicator tip is arranged to contact the surface of the component and dye penetrant is supplied onto the surface of the component from the applicator tip such that the dye penetrant enters any defects in the surface of the component. The applicator tip includes a porous and malleable member. Light is directed onto the component and the surface of the component is viewed through the boroscope to determine if any defects are present in the surface of the component.

Abstract: A method of analysing blade tip timing data obtained from an array (Pk) of stationary timing probes (3) that are spaced at integer multiples of a base angle. Replace one of the probes (3) with a virtual probe (Pv) to give a virtual probe set (42). Set an initial probe angle (?v) and an initial engine order (EOv) for the virtual probe (Pv). Calculate the condition number (CN) for the virtual probe set (42). If the condition number (CN) at least meets a threshold criterion, solve the virtual probe set (42) for blade tip displacement amplitude. Else increment the virtual probe angle (?v) and/or the virtual engine order and iterate from calculating the condition number. Else reinstate the replaced probe (3) and replace a different probe (3) from the array of probes (Pk) with the virtual probe (Pv); then iterate from setting the initial virtual probe angle and engine order.

Abstract: This invention relates to a laminated core for an electrical machine, including: a plurality of laminations configured to define a channel in a surface of the laminated core for the flow of a cooling fluid, wherein the channel has a base and at least one side wall, the at least one side wall having a stepped profile.

Abstract: An aircraft propulsion power plant for use in an aircraft includes one or more core engines housed in an airframe of the aircraft, one or more secondary propulsion units, each of the one or more secondary propulsion units being removably attached to the airframe, and one or more power transmission means, each of the one or more power transmission means being configured to transmit mechanical power from the or each core engine to a corresponding one of the or each secondary propulsion unit when the or each secondary propulsion unit is attached to the airframe.

Abstract: A method of analysing blade tip displacements (dijk) derived from a rotor having an array of blades that rotate at a rotational speed (?). The blades are monitored by an array of stationary timing probes for at least two revolutions (j) of the rotor. Define asynchronous displacement (dijk_A) as a sum of a sinusoidal term (Va) and an offset per probe term (Oo). Define synchronous displacement (dijk_S) as a sum of a sinusoidal term (Vs) and a common offset term (Cc). Solve the asynchronous displacements (dijk_A) using the blade tip displacements (dijk) to give asynchronous amplitude (|a|), offset per probe (ok) and asynchronous residuals (rijk_A). Solve the synchronous displacements (dijk_S) using the blade tip displacements (dijk) to give synchronous amplitude (|s|), common offset (cj) and synchronous residuals (rijk_S).

Abstract: A turbofan gas turbine engine (10) comprises a variable area exhaust nozzle (12) arranged at the downstream end of a casing (17). A control unit (66) analyzes the power produced by the gas turbine engine (10), the flight speed of the gas turbine engine (1) and/or the altitude of the gas turbine engine (10). The control unit (66) configures the variable area nozzle (12) at a first cross-sectional area (70A) when the flight speed of the gas turbine engine (10) is less than a first predetermined value. The control unit (66) configures the variable area nozzle (12) at a second, smaller, cross-sectional area (70B) when the flight speed of the gas turbine engine (10) is greater than the first predetermined value and the power produced by the gas turbine engine (10) is greater than a second predetermined value.

Abstract: An adhesive fastening element (602) for holding a workpiece (608), the adhesive fastening element (602) comprising: a body (604, 606) defining a recess (642) for receiving a protrusion (644) of the workpiece (608); wherein, in use, adhesive is applied between an end surface of the recess (642) and an end surface of the protrusion (644) and between a side surface of the recess (642) and a side surface of the protrusion (644) to bond the workpiece (608) to the adhesive fastening element (602). The workpiece (608) may be aligned with a reference point on the adhesive fastening element (602) and the adhesive cured to fix the position of the workpiece (608) relative to the adhesive fastening element (602).

Abstract: A fault tolerant electrical machine including: a plurality of phases; a detector arranged to detect a fault in at least one of the phases; and a controller arranged to intentionally cause a fault in at least one other of the phases such that the vector sum of the second harmonic power vectors of the remaining phases is zero.

Abstract: Disclosed is a unison ring assembly. The assembly comprises a first unison ring and a second unison ring concentrically aligned along a principal axis, the first and second unison rings being rotatable about the principal axis. The assembly further comprises a gear mechanism configured to simultaneously rotate the first and second unison rings about the principal axis.

Abstract: A method of determining rotor blade axial displacement (bij). The rotor blade tip (34) comprises first and second measurement features (36, 38) arranged to make an acute angle therebetween. Measure time of arrival (tijk) of the once per revolution feature (1), first and second edges (40, 42) of the first measurement feature (36), and first and second edges (44, 46) of the second measurement feature (38), for at least two revolutions of the rotor (2). Convert these to circumferential distances (dijk) for each revolution. Calculate a feature angle (?ijk) between each measurement feature (36, 38) and the once per revolution feature (1) for each revolution. Calculate blade untwist angle (?ij) from the change in feature angle (?ijk) between measured revolutions. Calculate the rotor blade axial displacement (bij) from the blade untwist angle (?ij) and the circumferential distance (dijk) of the point from one of the measurement features (36, 38).

Abstract: An intershaft seal is provided for inner and outer coaxial shafts which rotate relative to each other. The seal is located in an annular space between the shafts and maintains an axial pressure differential between a fluid pressure on a first side of the seal and a different fluid pressure on a second side of the seal. The seal includes first and second runners which project into the annular space from a first one of the shafts and extend circumferentially around the first shaft such that a cavity is formed between the runners. The seal further includes a sealing ring which is coaxial with the shafts and is located in the cavity.

Abstract: An adhesive fastening element (802) for holding a workpiece (808), the adhesive fastening element (802) comprising: an outer member (804); and a consumable inner member (806) disposed inside the outer member (804) and releasably movable relative to the outer member (804) along a longitudinal axis of the adhesive fastening element (802); wherein the consumable inner member (806) comprises a bonding surface which, in use, is bonded by an adhesive (810) to the workpiece (808) and is removed and replaced to detach the workpiece (808) from the adhesive fastening element (802).

Abstract: A method of recambering an aerofoil section. A position on one of the surfaces that intersects with a passage shock between adjacent aerofoils is determined and then projected as a shock position onto the camber line. A shock region encompassing the shock position and extending in a chordal direction towards the leading and trailing edges is defined. The camber line is recalculated in an upstream region using semi-inverse design. The camber line is extrapolated across the shock region to match a geometric criterion. The camber line is recalculated in a downstream region using semi-inverse design.

Abstract: A nickel-base alloy having the following composition (in weight percent unless otherwise stated): Cr 10.5-15.0; Co 1.7-8.8; Fe 0-5.9; Si 0-0.65; Mn 0-0.65; Mo 0.3-2.3; W 2.3-4.4; Al 2.7-4.1; Nb 1.0-4.2; Ti 1.0-3.0; Ta 2.0-5.0; Hf 0.0-0.6; C 0.02-0.06; B 0.015-0.035; Zr 0.035-0.11; S<20 ppm; P<60 ppm; the balance being Ni and incidental impurities. The alloy has an improved combination of properties (principally resistance to surface environmental damage and dwell fatigue crack growth) compared with known alloys, and is intended to operate for prolonged periods of time above 700° C., and up to peak temperatures of 800° C.