Abstract: An alternating current system 10 has a primary circuit 11 which forms a primary winding 18 on a core 16. A secondary winding 24 is connected with a current source 26 or, alternatively, with an impedance 60. The core 16 is threaded by a superconducting coil 20 having a current source 22. In normal use, current in the coil 20 provides a DC bias level of flux in the core 16, and the source 26 is varied to maintain substantially constant flux, thereby minimizing losses in the primary circuit 11. In fault conditions, current in the coil 20 is reduced or removed to increase voltage losses across the coil 18, thereby limiting fault current. The impedance 60 can also be switched into circuit, creating further current limiting by virtue of the transformer effect of the windings 18, 24.

Abstract: A cooling arrangement 21 for use within a gas turbine engine comprises a first shroud or platform 26 incorporating coolant passages 25 and a second shroud or platform 28. Generally, each platform or shroud 26, 28 will incorporate a pressure portion and a suction portion, with the pressure portion incorporating the coolant passages 25 through which the coolant flow 27 becomes incident on a surface 40 of the suction portion of the second shroud 28. The surface 40 is inclined or tapered towards the passage 25, such that there is limited direct impingement upon a front edge 39 of the surface 40. The coolant flow 27 thereby remains adjacent to the surface 40 for a longer period and so enhances cooling efficiency.

Abstract: A component can be formed by a hot isostatic pressing (HIP) process but it is necessary to reinforce intricate internal structures against collapse and deformation by the hot isostatic pressing process. The present method utilizes a low melting point salt or alloy reinforcement within the structure which can be released when molten through a drain from the internal structure. The reinforcement may be molten as a result of the hot isostatic process or through achieving a temperature with the component which causes the reinforcement to become molten but without damaging the component itself. The remaining parts of the reinforcement may be removed by use of a solvent or simple washing with a corrosive agent to remove any reinforcement debris.

Abstract: An apparatus and method converts a power generation combined cycle (CC) power plant to a load management compressed air energy storage (CAES) power plant. The CC power plant includes at least one combustion turbine, a heat recovery steam generator (HRSG) to receive exhaust heat from an associated combustion turbine, a steam turbine associated with the HRSG, and an electric generator associated with the steam turbine. An air storage stores compressed air. At least one compressor supplies the air storage with compressed air so that off peak energy can be converted to compressed air energy stored in the air storage. Compressed air from the storage is received by the HRSG and the HRSG provides heat to compressed air received from the air storage. The steam turbine receives heated compressed air from the HRSG and expands the heated compressed air to produce power.

Abstract: In a method of numerical modelling of the operation of a gas turbine engine, randomly chosen numerical modifications are made to values within the model, to represent a disturbance for triggering rotating stall. This results in a faster onset of rotating stall within the model, reducing the computational effort required to achieve this.

Abstract: A pressure rise combustor is provided with fuel provided at intermittent periods. The fuel is pulsed at timings such that the phase lag between the addition of the fuel and a resultant pressure rise is minimized. The fuel is pulsed such that the unsteady addition of heat reinforces the amplitude of an unsteady pressure fluctuation.

Abstract: A rotor blade tip arrangement is provided in which winglets extend from the end of rotor blade aerofoil walls. These winglets incorporate passages which extend to coolant apertures or holes in order to present a coolant flow about the tip of the turbine rotor blade. The winglets define at least an open ended gutter channel in order to inhibit leakage flow across the tip arrangement from a pressure side P to a suction side S. The coolant flow facilitates cooling of the arrangement despite any heating caused by leakage flow across the arrangement.

Abstract: A method of making a formed, dried lignocellulose fiber material comprising (a) providing an aqueous lignocellulose fiber pulp slurry having an effective consistency; (b) de-watering the slurry to provide a de-watered material at an effective de-watering rate under an effective pressure to prevent or reduce the formation of fissures and voids within the material; (c) drying an effective amount of the de-watered material at an effective temperature and period of time to provide the formed, dried lignocellulose fiber material having a thickness of at least 5 mm. The formed, dried lignocellulose material may be used to make a lignocellulose fiber-resin composite material of use as a cost effective structural member, as a substitute for steel, in, for example, bridges, processing equipment, and the like.

Abstract: A device for positioning and locking a head clamp in a selective position including a first arm, a second arm and a third arm. The third arm having a free end including both a spherical member carried in a socket and including a mounting tube and a gripping device to restrain movement of said spherical member. The head clamp includes a mounting post for insertion to said mounting tube wherein said mounting tube includes a releasable locking device for engaging and holding said mounting post against rotation and withdrawal of said mounting tube to prevent accidental release of the mounting post.

Abstract: A DC electrical current busbar associated with electrical load circuits and devices as well as sources requires protection. In order to provide such protection Kirchoff's laws are utilized such that electrical current values are substantially simultaneously taken and summed in order to identify deviations from expected differential threshold values. Upon detection of such deviations and generally as a result of a number of successive deviations an electrical isolation device is utilized in order to isolate electrical current to the busbar. The data set of electrical current values can be utilized in order to provide a back up protection system for individual electrical load devices and circuits, by similar comparison with expected values for those devices and circuits.

Abstract: A pre-reformer (10) comprises a non-electrically conducting gas tight duct (12) and an electrically conducting wire (14) arranged in the duct (12). The electrically conducting wire (14) is electrically isolated from the duct (12). The duct (12) has an inlet (16) for receiving a hydrocarbon fuel at a first end (18) and an outlet (20) for supplying a pre-reformed hydrocarbon fuel at a second end (22). At least the inner surface (24) of the duct (12) is chemically inert with respect to the hydrocarbon fuel. An electrical power supply (26) is electrically connected to the electrically conducting wire (14) and a control means (28) controls the supply of electrical current through the electrically conducting wire (14) to maintain the electrically conducting wire (14) at a temperature to provide selective thermal decomposition of higher hydrocarbons in the hydrocarbon fuel. The performer reduces coking in associated fuel cells and other parts of a fuel cell system.

Abstract: A cooling system for a gas turbine engine (FIG. 1) comprises a pre-swirl arrangement, preferably including a pre-swirl chamber, for providing cooling air to a turbine blade disc, and a ventilation arrangement for providing ventilation air to a rotating component of the gas turbine engine. The cooling system includes an air bypass arrangement, which preferably includes first, second and third air bypass duct portions, for conveying ventilation air away from the pre-swirl arrangement.

Abstract: A CAES system (10) includes an air storage (18), a compressor (20) supplying compressed air to the air storage, a power generating structure (11, 102), a heat exchanger (24), an auxiliary combustor (27), an air expander (30), and an electric generator (32). The system operates in one of modes a) a main power production mode wherein the auxiliary combustor is inoperable and the power generating structure is operable, to produce power by the air expander, fed by the heated compressed air received from the air storage, in addition to power produced by the power generating structure, or b) a synchronous reserve power mode wherein the auxiliary combustor is operable and the power generating structure is inoperable, with compressed air withdrawn from the air storage being preheated by the auxiliary combustor that feeds the air expander, with the air expander expanding the heated air and the generator providing immediate start-up power.

Abstract: An InfiniBand™ network node includes a network interface, a system memory, a memory controller configured for controlling access to the system memory, and a processor. The network interface is configured for outputting data packets according to a prescribed flow control protocol that specifies flow control resources. The network interface also is configured for outputting a data flow interruption request to the memory controller based on a determined depletion of the flow control resources. The memory controller, in response to reception of the data flow interruption request, restricts access to the system memory. Hence, the processor, in response to detecting the restricted access to the system memory, reduces execution of a prescribed application resource based on the determined depletion of the flow control resources.

Abstract: A method of ensuring robust operation of a differential serial link is provided. The method provides a first integrated circuit having 1) a phase generator constructed and arranged to provide a programmable shift of a clock signal based on selective interpolating between first and second phases of the clock signal relative to a digital phase value, and 2) a transmit driver constructed and arranged to control, in a programmable manner, a differential voltage of digital data signals. A second integrated circuit is constructed and arranged to receive the clock and digital data signals sent by the first integrated circuit. The clock and digital data signals are sent substantially simultaneously through the link from the first integrated circuit to the second integrated circuit. It is determined whether the digital data signals can be sampled reliably by the second integrated circuit relative to the digital phase value.

Abstract: Within a power generating arrangement 1 it is typically necessary to provide a coupling with an electrical power distribution cable 5. Previously this was sometimes achieved through use of brush gear and slip rings but such arrangements are subject to regular replacement for wear, maintenance and also there is a requirement to control humidity about the brush gear coupling. Alternatively, a system allowing an amount of rotation, limited by cable wind up was used. By providing a transformer in which windings 15, 16; 36, 37 are physically separated by an air gap 14, 39, but still induce voltage from variation in the magnetic flux, it is possible to create a power generating transfer transformer which can be rotated while driving electrical current for an external load.

Abstract: A phase selection circuit having a selection circuit, binary weighted current sources, and an amplifier circuit. The phase selection circuit is configured for selecting adjacent phase signals from a number of equally-spaced phases of a clock signal, based on a phase selection value. The selection circuit outputs the adjacent phase signals to respective first and second binary weighted current sources, along with a digital interpolation value. The first current source outputs a contribution current onto a summing node based on the first adjacent phase signal and the digital interpolation control value, and the second current source outputs a second contribution current to the summing node based on the second adjacent phase signal and an inverse of the digital interpolation control value, resulting in an interpolated signal. An amplifier circuit outputs the interpolated signal as a phase-interpolated clock signal according to the phase selection value.

Abstract: A stage of fan aerofoils (10) lies within a fan cowl (12). The fan duct (16) is defined in part by a hard casing (14) that in turn surrounds aerofoils (10). Hard casing (14) includes wedge members (26) that fill the annular gap between ring (14) and an outer ring (20). In the event of an aerofoil (10) breaking off, the hard ring (14) and wedges (26) absorb sufficient of the kinetic energy expended by the broken aerofoil (10), as to prevent it passing through outer ring (20) on to the fan cowl (12).

Abstract: A heat exchanger (10) comprises a first sheet (12), a second sheet (14) and an additional sheet (30). The first and second sheets (12, 14) are wound around an axis (X), each sheet (12, 14) has hot and cold edges at the hot and cold ends (16, 18) respectively of the heat exchanger (10). The hot and cold edges of the first sheet (12) are joined to the hot and cold edges of the second sheet (14). The end (12A) of the first sheet (12) is joined to the second sheet (30) by an axially extending join (28) at a position spaced from the end (14A) of the second sheet (14). The end (30A) of the additional sheet (30) is joined to the end (14A) of the second sheet (14) by an axially extending join (28). The additional sheet (30) is thicker and wider than the first and second sheets (12, 14) such that at least one of the hot and cold edges (30C, 30D) of the additional sheet (30) extend beyond the hot and cold edges of the first and second sheets (12, 14).

Abstract: A blade for a gas turbine engine comprises an aerofoil having a root portion, a tip portion located radially outwardly of the root portion, and leading and trailing edges extending between the root portion and the tip portion. A shroud extends transversely from the tip portion of the aerofoil and the aerofoil defines interior cooling passages which extend between the root portion and the tip portion. The aerofoil includes a wall member adjacent the trailing edge and a support structure extending from the wall member to the shroud to support the shroud. The support structure permits a flow of cooling air from a cooling passage to the trailing edge at a region proximate the tip portion of the aerofoil. Optionally, the aerofoil also includes a flow disrupting arrangement.