Abstract: Provision of flow control arrangements which can be switched from high flow restriction to low flow restriction or vice versa are desirable. It is known to use switched vortex valves comprising a vortex chamber having a diverter portion which jets a through flow into either radial presentation to an outlet or tangential presentation with differential flow restrictions. Typically deflection is through cross flows presented from control ports as determined by mechanically actuated and controlled valves. Sensors are required to determine pressure differentials in order to actuate these moving part valves. By providing association between the control ports and an outlet path along with appropriate configuration and sizing of the flow regulators switching states can be provided through the cross flows presented via the flow regulators between the high and low through flow restriction. The flow regulators generally comprise orifice restrictors, diffusers/venturi arrangements or vortex throttles.

Abstract: Cooling jets 1 are provided with a longitudinal aspect 2 greater than width 3. Thus, the coolant flow through the jet 1 is less susceptible to deflection by lateral or cross flows presented to that coolant flow such that cooling by impingement of the coolant flow upon a surface 7 to be cooled is improved. Typically, a plurality of jets 1 are provided in a housing wall 8. These jets 1 will be arranged in an appropriate pattern to achieve cooling by flow impingement upon the surface 7 to be cooled. Possibly, a plurality of jets 1 in an appropriate pattern may be arranged upstream of conventional circular coolant jets in order to provide some protection for those circular coolant jets from lateral or cross flow.

Abstract: It is necessary to support components while machining is performed. In such circumstances work supports are now provided, whilst previously there was a dedicated arrangement for each component to be supported. By achieving a modularity in terms of adjustment through creating mountings comprising rings, arcs or bars secured upon posts a rigidity of presentation of support ends is achieved. By providing spacers for location about the posts on the mountings variability with regard to the positioning of the support ends is achieved such that similar geometry but different sized components and articles can be supported by the support arrangements. Furthermore, the spacers may be readily removed if C shaped, and the rings, arcs or bars can be shifted.

Abstract: A shrouded nozzle arrangement for a gas turbine engine exhaust comprises a shrouded nozzle and duct means. The exhaust nozzle is translatable from a first position, wherein the exit plane of the nozzle lies upstream of the exit aperture of the shroud, to a second position, wherein the exit plane of the exhaust duct lies substantially downstream of the exit aperture of the shroud. In this second position, the use of reheat or thrust vectoring may be used without damage to the shroud.

Abstract: Calibration apparatus comprising a positional calibration means, and a machine tool assembly chuck configured to, in use, locate a machine tool assembly comprising a machine tool configured to be adjustably mounted on a machine tool mount. The positional calibration means and chuck are mounted on a common base relative to one another. The positional calibration means comprises a calibration headstock provided with a positional feature engagement means for cooperative engagement with a machine tool location feature provided on the machine tool. When the machine tool is adjusted on the machine tool mount relative to the positional calibration means, cooperative engagement of the positional feature engagement means and the machine tool location feature indicates the machine tool is aligned along a predetermined machine tool calibration axis.

Abstract: A nose cone assembly for a gas turbine engine comprises a spinner and a plurality of circumferentially spaced mounting members for mounting the spinner on a fan hub of the gas turbine engine. Each of the mounting members is rigid in a generally axial direction and flexible in a generally radial direction.

Abstract: Features such as holes 10 in a component which may be an aerofoil component of a gas turbine engine are re-drilled after initial formation, for example to remove blockages created in a coating process. In order to ensure that re-drilling occurs at the precise location of the initial holes, a selected number of the holes A-F are selected, and their exact positions identified, for example by camera imaging and image processing. The actual positions of the selected features are compared with the nominal positions, and an algorithm is generated and then used to calculate the actual positions of the non-selected holes of the array.

Abstract: A mixed propulsion system for a seagoing vessel such as a liquid natural gas carrier including a gas turbine engine is described. The vessel has at least one electric propulsion drive and a plurality of prime movers of different types each coupled directly to drive an electrical generator. The outputs of the several generators are connected to at least two electricity distribution switchboards to supply the power requirements of the vessel, and each electric propulsion drive is cross-coupled to receive power selectively from either switchboard such that in the event of a single failure in a switchboard or prime mover or both power can be maintained to both propulsion drives.

Abstract: A fan track liner within a rotor blade assembly 26 for a gas turbine engine (10, FIG. 1) comprises a radially inner casing liner member 28 and a radially outer casing liner member 30 adjacent to the radially inner casing liner member 28. A septum 32 is interposed between the radially inner and radially outer casing liner members 28, 30 and bonds together the radially inner and radially outer casing liner members 28, 30. The septum 32 includes predetermined weakened regions 36 which permit penetration of the septum 32 in use by a rotor blade in the event of impact of the radially inner casing liner 28 member by a detached rotor blade. Assembly 26 otherwise capable of resisting ice shed from the blade impacting the same region 36.

Abstract: A gas turbine engine exhaust nozzle arrangement for the flow of exhaust gases therethrough between an upstream end and a downstream end thereof comprising a nozzle and a plurality of tabs which extend in a generally axial direction from a downstream portion of the nozzle wherein the nozzle further comprises an actuation mechanism capable of moving the tabs between a first deployed position, where the tabs interact with a gas stream to reduce exhaust noise thereof, and a second non-deployed position, where the tabs are substantially aerodynamically unobtrusive.

Abstract: An annulus filler is provided for mounting to a rotor disc of a gas turbine engine and for bridging the gap between two adjacent blades attached to the rotor disc. The annulus filler has a body portion which defines an airflow surface for air being drawn through the engine, and one or more hook portions which extend radially inwardly from the body portion. The hook portions are for connection to corresponding engagement portions on the radially outer face of the rotor disc. The or each hook portion is attached to the body portion by a joining arrangement in which a wedge part provided by one of the hook portion and the body portion is received in a complementary-shaped retention recess provided by the other of the hook portion and the body portion.

Abstract: A component comprises a multiplicity of cooling passages arranged in two intersecting arrays to form a multiplicity of cooling passage intersections. Air jet interactions are generated at cooling passage intersections when air is passed through the cooling passages. The spacing of the passages in at least one of the arrays is chosen to provide a predetermined range of intersection density in a selected region or regions of the component.

Abstract: A generator control arrangement for an electrical power generator, the arrangement comprising a controller arranged to regulate output voltage from a generator to a target value, the controller including a voltage comparator for comparing a presented voltage with a desired output voltage, the presented voltage derived in a transfer comparator by combination of a reference voltage value and an error value between a reference electrical current value and a measured electrical current value subject to a processor gain whereby the processor gain can be specifically set at zero to enable control by voltage or the processor gain can be specifically set at greater than zero to enable control by electrical current.

Abstract: A gas turbine engine airfoil (22) has a wall (42) provided with a cooling effusion hole (40) therein to facilitate film cooling of the external surface (52) of the wall (42). A member (46) attached to the internal surface (48) of the airfoil wall (42) is provided with an aperture (44) which at least partially overlaps the cooling effusion hole (40). The airfoil wall (42) and member (46) are formed from materials having different coefficients of thermal expansion and are mounted such that over a temperature range, the aperture (44) and cooling effusion hole (40) interact to a greater or lesser extent to modulate the flow of cooling air therethrough.

Abstract: A wall element for a combustion space, the wall element comprising a ceramic body, a support within the body, and attachment means extending from the support and protruding from the body for securing the ceramic body to a combustion space wall.

Abstract: A bleed valve bleeds hot gases from a compressor into a bypass duct of a gas turbine engine. The valve comprises a diffuser having opposing walls and a divider located between the walls and which define at least two passages through which a bleed fluid flows and into a fluid flow through the bypass duct. The passages are angled towards each other to force the two gas flows together to form a high aspect ratio plume. This plume has a relatively large surface area that that improves mixing with the bypass flow to cool it and prevented otherwise hot bleed flows from impinging on heat sensitive components adjacent the bypass duct.

Abstract: Provision of component structures with line core elements are known but enhancing beyond a certain level of stiffness for impact resistance is difficult in view of manufacturing tolerances and bond region ratios. By providing discontinuous core elements 102, 32, 42 with through bonding creating gaps 39, 49 between them, bond regions 36, 46 are created. In such circumstances enhancement of local impact or load resistance through achieving specific desired support about the bond regions 46 can be achieved whilst remaining flexible (elastic) enough to resist cracking due to high cycle fatigue. In such circumstances within a structure 101, 41 both continuous core elements 40 and discontinuous core elements 42 can be provided and formed by simple plastic deformation in a single process whilst maintaining manufacturing tolerances and acceptability with regard to bond formation.

Abstract: A method and apparatus for detecting an abnormality in e.g. in operating characteristics or function of a machine, apparatus or system, the method including providing a data sample set comprising n values of a measured physical parameter associated with the apparatus or system generated by repeating a measurement of the physical parameter n times. An extremal measured parameter value is selected from amongst the data sample set, determining a probability of observing the selected parameter value (e.g. of observing a value not exceeding the selected parameter value) by applying the selected parameter value to an extreme value probability distribution function having a location parameter and a scale parameter. The value of the location parameter and the value of the scale parameter are each constructed using an integer value m (e.g. notionally representing the size of a sub-sample data set comprising m of said measured parameter values) in which m is less than n (i.e. m<n).

Abstract: An outer ring for a rolling element bearing has three mounting pads on its outer surface. The inner surface of the ring is arranged to be non-circular, with its effective radius being at a minimum at the three points midway between adjacent pairs of mounting pads. This provides a preload on the rolling elements of the bearing in use, preventing skidding, but because the ring is not supported between the pads it can still flex under loads. The ring may be oriented in use so that transient loads are directed through one of the mounting pads.

Abstract: To determine free field thrust of a gas turbine engine, the gas turbine engine may be attached to a movable support, and operated at a selected engine operating point. The thrust applied by the engine to the thrust cradle is measured. The gas turbine engine intake momentum drag generated by airflow into the gas turbine engine intake, the thrust cradle drag force generated by airflow past the moveable support of the thrust cradle, the base drag generated as a result of accelerating nozzle ejector airflow, a pre-streamtube force related to turning of stream lines in the intake air path, a pre-stream tube force related to a bell mouth pull-off force are calculated. Forces due to forward anemometer plane and nozzle static pressures, and a nozzle exit buoyancy force are summed according to respective positive and negative values to determine the free field thrust at the selected engine operating point.