In one embodiment, the invention provides an apparatus for caching data in a network, with the apparatus including a proxy cache configured to receive request for an object from a client and to fetch data blocks from a server. The proxy cache may be configured to cache the data blocks in a hierarchical relationship within the object. The object may be, for example, a data file or a directory. The data blocks that are cached in the proxy cache define an active data set which is based upon a request from a client.

Apparatus and method for a proxy cache

Holes 38 and 39 have upstream opening portions 38b and 39b and downstream opening portions 38a and 39a which have a larger cross-sectional area than upstream opening portions 38b and 39b, and are formed at top portion TP of each moving blade. Holes 38 and 39 have tapered shapes T1 and T2 or step portions, and preferably, downstream opening portions 38a and 39a are eccentrically formed toward the moving direction. When tip squealer 37 is formed, hole 38 is formed so that its opening portion is provided at the side surface of tip squealer 37. Without covering the holes for cooling which are formed at the top portion of the turbine blade due to rubbing or the like, the turbine blade is accurately cooled and stably driven.

Turbine blade and gas turbine

Aspects of the invention relate to a modular turbine vane assembly. The vane assembly includes an airfoil portion, an outer shroud and an inner shroud. The airfoil portion can be made of at least two segments. Preferably, the components are connected together so as to permit assembly and disassembly of the vane. Thus, in the event of damage to the vane, repair involves the replacement of only the damaged subcomponents as opposed to the entire vane. The modular design facilitates the use of various materials in the vane, including materials that are dissimilar. Thus, suitable materials can be selected to optimize component life, cooling air usage, aerodynamic performance, and cost. Because the vane is an assemblage of smaller sub-components as opposed to one unitary structure, the individual components of the vane can be more easily manufactured and more intricate features can be included.

Multi-piece turbine vane assembly

A vane has an airfoil shell and a spar within the shell. The vane has an outboard shroud at an outboard end of the shell and an inboard platform at an inboard end of the shell. The shell includes a region having a depth-wise coefficient of thermal expansion and a second coefficient of thermal expansion transverse thereto, the depth-wise coefficient of thermal expansion being greater than the second coefficient of thermal expansion.

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Ceramic matrix composite turbine engine vane

A metal vane core or strut (64) is formed integrally with an outer backing plate (40). An inner backing plate (38) is formed separately. A spring (74) with holes (75) is installed in a peripheral spring chamber (76) on the strut. Inner and outer CMC shroud covers (46, 48) are formed, cured, then attached to facing surfaces of the inner and outer backing plates (38, 40). A CMC vane airfoil (22) is formed, cured, and slid over the strut (64). The spring (74) urges continuous contact between the strut (64) and airfoil (66), eliminating vibrations while allowing differential expansion. The inner end (88) of the strut is fastened to the inner backing plate (38). A cooling channel (68) in the strut is connected by holes (69) along the leading edge of the strut to peripheral cooling paths (70, 71) around the strut. Coolant flows through and around the strut, including through the spring holes.

CMC Vane Assembly Apparatus and Method

A ceramic matrix composite material (CMC) vane for a gas turbine engine wherein the airfoil member (12) and the platform member (14) are formed separately and are then bonded together to form an integral vane component (10). Airfoil member and the platform member may be bonded together by an adhesive (20) after being fully cured. Alternatively, respective joint surfaces (16,18) of the green body state airfoil member and platform member may be co-fired together to form a sinter bond (30). A mechanical fastener (38) and/or a CMC doubter (42) may be utilized to reinforce the bonded joint (40). A matrix infiltration process (50) may be used to create or to further strengthen the bond.

Ceramic matrix composite turbine vane

A method of manufacturing a composite structure uses a layer of an insulating material ( 22 ) as a mold for forming a substrate of a ceramic matrix composite (CMC) material ( 24 ). The insulating material may be formed in the shape of a cylinder ( 10 ) with the CMC material wound on an outer surface ( 14 ) of the cylinder to form a gas turbine combustor liner ( 20 ). Alternatively, the insulating material may be formed in the shape of an airfoil section ( 32 ) with the CMC material formed on an inside surface ( 36 ) of the insulating material. The airfoil section may be formed of a plurality of halves ( 42, 44 ) to facilitate the lay-up of the CMC material onto an easily accessible surface, with the halves then joined together to form the complete composite airfoil. In another embodiment, a box structure ( 102 ) defining a hot gas flow passage ( 98 ) is manufactured by forming insulating material in the shape of opposed airfoil halves ( 104 ) joined at respective opposed ends by platform members ( 109 ). A layer of CMC material ( 107 ) is then formed on an outside surface of the insulating material. A number of such composite material box structures are then joined together to form a vane ring ( 100 ) for a gas turbine engine.

Composite structure formed by cmc-on-insulation process

An airfoil, a method of manufacturing an airfoil, and a system for cooling an airfoil is provided. The cooling system can be used with an airfoil located in the first stages of a combustion turbine within a combined cycle power generation plant and involves flowing closed loop steam through a pin array set within an airfoil. The airfoil can comprise a cavity having a cooling chamber bounded by an interior wall and an exterior wall so that steam can enter the cavity, pass through the pin array, and then return to the cavity to thereby cool the airfoil. The method of manufacturing an airfoil can include a type of lost wax investment casting process in which a pin array is cast into an airfoil to form a cooling chamber.

Scott M. Widrig

Papers

Ceramic matrix composite turbine vane

Composite structure formed by cmc-on-insulation process

Closed loop steam cooled airfoil