Abstract: A fuel cell arrangement comprises at least one fuel cell module, each fuel cell module comprises a plurality of fuel cells. Each fuel cell module is hollow and defines a chamber. Each fuel cell module is arranged within an inner vessel and the inner vessel is arranged within an outer pressure vessel. Means to supply oxidant is arranged to supply oxidant to the space within the inner vessel so as to supply oxidant to the cathode electrodes. Means to supply fuel is arranged to supply fuel to the chamber in each fuel cell module so to supply fuel to the anode electrodes. The outer pressure vessel is protected from the high temperature environment of the fuel cells by the inner vessel. The outer pressure vessel forms the main pressure containment of the arrangement and operates at a lower temperature and operates with a greater safety margin than a single pressure vessel arrangement.

Abstract: Embedding electrical machines in gas turbine engines has particular advantages by avoiding the need to provide mechanical connections. However, electrical machines such as switched reluctance electrical machines require relatively large electrical capacitors to accommodate and filter voltage variations in the phases of the electrical machine. Generally, the electrical machine will have a motoring period or generating period with a spacer period between. By injecting electrical current as electrical power in the spacer period, there is limited effect upon net torque within the electrical machine or electrical power generation. However, such stored electrical power in an inductive winding element of the electrical machine augments power pulses provided by a power source incorporating an electrical capacitor. In such circumstances, a smaller sized electrical capacitor can be used.

Abstract: A method of forming a component from solid freeform fabrication comprising the step of building an integral support around the component during manufacture thereof. The stiffness the support provides to the component is selected to minimise deformation of the component either during the manufacture of the component or during a subsequent heat treatment process.

Abstract: An instrumentation arrangement for a component comprises a plurality of measurement devices mounted on a baseplate. The baseplate is shaped to correspond to the surface of the component in use, and has attachment features engageable with features of the component, so that the rake can be easily installed and removed without modification of the component.

Abstract: Blades for gas turbine engines which are formed from composite materials have problems with respect of resistance to impacts such as bird strikes. Previous blades formed from metals had some ductility towards the trailing edge which could accommodate the whiplash effects of impacts. With regard to composite materials such ductility is not present. By providing projections 32 which act as propagation wave trips as well as high intensity reflectors 36 it is possible to limit the whiplash at the edge 31 resulting in damage. Typically a cladding cap 38 is provided which also may be formed from a metal to allow some greater uniformity with respect to mass per length despite the tapering of the blade. Furthermore by providing voids which act as delamination initiation sites cracking can be provided between plies which allows greater flexibility towards the edge and therefore release of energy. These voids may incorporate uncured polymer matrix to act as a binder subsequent to delamination.

Abstract: A method of manufacturing a rotating component (110), the method comprising the following steps: providing a component comprising a first portion (20, 40, 60, 80, 100, 116), which first portion defines a first cavity (26, 46, 66, 86, 106), characterised by; identifying a first inertial property of the first portion and/or the entire component, introducing material (28, 48, 68, 88, 108) into the first cavity to achieve an adjusted inertial property of the first portion and hence a desired inertial property of the component. A rotating component (110) comprising: a first portion (20, 40, 60, 80, 100, 116) defining a first cavity (26, 46, 66, 86, 106), a second portion (118) defining a second cavity, the second portion being circumferentially spaced from said first portion, characterised in that the first cavity has a first material (28) deposit therein, said material having predetermined inertial characteristics so as to adjust the centre of mass (Z) of the rotating component.

Abstract: In order to avoid external bulging (5) to accommodate accessory mechanisms (27) and gearboxes (30) to drive these mechanisms (27) in accordance with the present invention splitter fairings (26) are located within a bypass duct (23) of an engine (20). The bypass duct (23) is defined between a casing (21) and compressor/turbine propulsion core (22). The fairings (26) are of sufficient dimensions to accommodate the accessory mechanisms (27) whilst the bypass duct (23) is appropriately shaped axi-symmetrically to eliminate and balance any blocking effect of these fairings (26) within the duct (23) upon air flow (24). Further fairings (26?) may be provided to accommodate oil tank reservoirs (34) as well as filter/heat exchanger mechanisms (35) for the engine (20). In such circumstances, a notional elongate cylindrical profile for the engine (20) is maintained such that a reduced cross section is require for that engine (20) and so allowing a smaller airframe with better sonic boom signature.

Abstract: A fluid monitoring arrangement 1 for an engine is operated in accordance with a method whereby nuclear magnetic resonance (NMR) interrogation of the fluid flow 3 it is possible to determine whether appropriate fluids and additives are being utilised as well as whether potential detrimental actions occur such as engine wear and carbonisation through particulate components within the flow 3. Generally, an expected signal response from the fluid flow 3 is determined and the actual signal response compared in a comparator 8 with that expected signal response. Divergence in the actual signal response and in particular with regard to its profile is identified and an indication provided in a display 10 with regard to the potential coolant of such divergence. Normally, a reference library 11 is provided of expected signal responses for comparison in the comparator with the actual signal responses.

Abstract: A magnetic bearing has two bearing members each of which carries a set of bearing elements. The bearing elements carried by one member are interleaved with the bearing elements carried by the other member to define three or more substantially parallel interleaf gaps between successive elements, so that bearing forces can be developed as a result of magnetic shear stresses acting across those gaps. The magnetic bearing achieves its bearing forces as the sum of force contributions from a number of parallel (or nearly-parallel) airgaps and each of these individual airgap force contributions comes about as the integration of magnetic shear stress over the airgap area brought about by causing lines of magnetic flux to cross the airgap at an angle to the normal.

Abstract: Appropriate location of components such as vanes in gas turbine engines is important. These components are located between tangs held in interference engagement. There are four relatively rigid mounting points constituted by the tangs engaging respective opposed slots in a casing or a mounting ring. Only three point limitation with respect to displacement and rotation is adequate so provision of a fourth locator causes unnecessary constraint. A relatively resilient or compliant locator means it is possible to reduce the amount of constraint upon the component mounting whilst the other locators are adequate for positioning of the component.

Abstract: A method of drilling through a wall of a hollow component in which a high energy beam is directed at an outer surface of the wall and emerges into a cavity from an inner surface of the wall, comprising the step of providing in the cavity a medium comprising a ceramic dispersed within a silica sol.

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: A method of manufacturing a component such as a gas turbine fan blade. The method comprises: disposing a plurality of webs between a plurality of panels; and deforming the panels and the webs by applying internal pressure between the panels, thereby forming a series of internal cavities (15) partitioned by the webs (20-22). Weakened regions (30a,30b,30c) are formed in the webs which open to form holes (30) in the webs (20-22) during the deformation step. A damping material (17) is introduced into at least one of the cavities (15) whereby it flows from the cavity into the other cavities via the holes in the webs.

Abstract: An acoustic panel for a fan casing of a gas turbine engine includes one or more Helmholtz resonators to absorb acoustic energy propagated upstream from the fan. By arranging that the periodic air flow out of the resonators has some axial momentum, by inclining the passages that from the necks of the resonators in a downstream direction, some of the energy in this air flow can be realised as a useful pressure rise in the direction of the air flow into the fan, rather than a pressure drop as in known acoustic panels.

Abstract: Firing of ceramic cores (1) is important in order to achieve manufacturing processes. These ceramic cores (1) are generally formed in a “green” state which has limited mechanical strength and may be distorted during the firing process by non-uniform thermal effects, etc. By providing a tube or containment 2 which is located on a saggar base 3 and surrounded by firing media 4, it is possible to achieve an initial pre-firing step whereby the “green” state core 1 is located through a stem 1a in an initial partial depth 5 of firing media 4 in the tube or containment 2 until it achieves a sufficient mechanical strength to enable positional adjustment. Thus, the green core will be pre-fired in a kiln solely supported through the stem 1a and then the core adjusted using a tool such as an engineering rule.

Abstract: A method of constructing a piecewise linear engine performance model, comprises the steps of: (a) providing a non-linear engine performance model which iteratively calculates engine performance variables y from a plurality of sub-models, each sub-model representing the performance of a component of the engine; (b) defining a plurality of engine power conditions, each engine power condition being defined by one or more engine state variables x; (c) for each of the engine power conditions, using the non-linear engine performance model to determine partial derivatives ?y of the engine performance variables y with respect to engine control variables u and with respect to the engine state variables x, the values of the partial derivatives ?y being determined so that, on integrating the partial derivatives ?y, the error between steady state values for the engine performance variables y calculated by the non-linear engine performance model and steady state values for the engine performance variables y calculated

Abstract: A magnetic coil 32 for an electrical machine is constructed from two sub-conductors 34A, 34B, each in the form of laminae of conducting material such as copper sheet, coated with an insulating material. At one end of the coil, the sub-conductors extend by different distances, to provide space at 39 for a transposition of the sub-conductors.

Abstract: A solid oxide fuel cell module (30) comprises a plurality of fuel cells (36). Each fuel cell (36) comprises a first electrode (40), an electrolyte (42) and a second electrode (44). A plurality of interconnectors (38) are arranged to electrically connect the fuel cells (36) in electrical series. Each interconnector (38) electrically connects a first electrode (40) of one fuel cell (36) to a second electrode (44) of an adjacent fuel cell (36). The first electrode (40) comprises a first layer (40A) on the electrolyte (42 to optimize the electrochemical activity at the electrolyte (42) and a second layer (40B) on the first layer (40A) to provide electronic conduction perpendicular to the layers (40, 42, 44) of the fuel cell (36). The second layer (40B) is arranged such that electronic conduction perpendicular to the layers (40, 42, 44)) of the fuel cell (36) is different at different positions in the second layer (40B).

Abstract: A method is provided whereby confidence in a validation parameter set is achieved by comparison with a known sample of a parameter in terms of the expected template comparison score as well as mean values and deviation from that score. Thus, with respect to user individual identification, biometric parameters such as fingerprint or handwriting or voice recognition can be utilised to compare the stored template for that individual with the putative biometric response in order to determine deviation from the mean. Previous systems provided a stored template and then ranging either side to simply give a pass/fail response. By adaptation of the ranging quotient for a particular individual, a percentage confidence in the pass/fail response can be achieved. For example an individual -may have a wider range of deviation than another individual and therefore close repetition of the biometric data may be indicative of a lower percentage confidence than with an individual with a narrower deviation.

Abstract: Turboprop and propfan engines generally incorporate blades which have variable pitch to improve operational efficiency. Variable pitch is achieved through a pitch control mechanism at the root of the blade but such mechanisms may fail resulting in the blades turning to define a flat configuration with low drag and therefore the potential for engine damage through over-speeding. Traditional pitch lock and counter weight control mechanisms have disadvantages. By providing a helical bearing in which the mass and radial movement due to centrifugal radial force are utilised it is possible to generate a counter moment to the normal centrifugal turning moment (CTM) to ensure the blade remains in a configuration with at least some drag to limit engine rotational speed. The continuous helical bearing allows for a range of pitch angular positions to be used around a full 360° turn by providing a feathering counter moment from any of those angular positions.