Abstract: An apparatus and method for varying the cooling air flow within a gas turbine bucket tip. Each turbomachinery blade contains at least one radial cooling passage located between a hollow interior and an outside of the blade. A transversely-oriented elongate channel connects at least one of the cooling passages with the trailing edge of the blade. Secured within the transversely-oriented channel is a pin which extends into at least one of the radial cooling passages to partially obstruct the cooling fluid flow depending on the needs of the design.

Abstract: In the method for fabrication of water-cooled composite nozzle and bucket hardware for high temperature gas turbines, a high thermal conductivity copper alloy is applied, employing a high velocity/low pressure (HV/LP) plasma arc spraying process, to an assembly comprising a structural framework of copper alloy or a nickel-based super alloy, or combination of the two, and overlying cooling tubes. The copper alloy is plamsa sprayed to a coating thickness sufficient to completely cover the cooling tubes, and to allow for machining back of the copper alloy to create a smooth surface having a thickness of from 0.010 inch (0.254 mm) to 0.150 inch (3.18 mm) or more. The layer of copper applied by the plasma spraying has no continuous porosity, and advantageously may readily be employed to sustain a pressure differential during hot isostatic pressing (HIP) bonding of the overall structure to enhance bonding by solid state diffusion between the component parts of the structure.

Abstract: A method of fabricating a composite nozzle for water-cooled, high temperature gas turbines is provided wherein the nozzle comprises a thermally conducting copper core, a top endwall, a bottom endwall, metal tubing through which water may pass embedded in and extending through the core and into the endwalls and a preformed cladding to protect the nozzle against corrosion. The method utilizes hot isostatic pressure to diffusion bond the nozzle components into an assembly and bond the corrosion resistant cladding to the outer surface of the assembly.

Abstract: A method for forming a liquid cooled airfoil for a gas turbine is disclosed. A plurality of holes are formed at spaced locations in an oversized airfoil blank. A pre-formed composite liquid coolant tube is bonded into each of the holes. The composite tube includes an inner member formed of an anti-corrosive material and an outer member formed of a material exhibiting a high degree of thermal conductivity. After the coolant tubes have been bonded to the airfoil blank, the airfoil blank is machined to a desired shape, such that a portion of the outer member of each of the composite tubes is contiguous with the outer surface of the machined airfoil blank. Finally, an external skin is bonded to the exposed outer surface of both the machined airfoil blank and the composite tubes.

Abstract: A method of fabricating complex, composite components for water-cooled, high temperature gas turbines is provided. The method utilizes hot isostatic pressure with molten glass as a pressure transmitting medium. Metal tubing and cladding are bonded to a component core under conditions such that the ends of the tubing extend above the molten glass whereby the pressure inside and outside of the tubing is maintained at equilibrium to prevent collapsing thereof during the application of hot isostatic pressure.

Abstract: Individual coolant passages in the airfoil portion of a liquid-cooled turbine bucket are each provided with a plurality of inwardly protruding circumferentially-extending crimps or rings located at spaced intervals along each passage, each crimp, protrusion or ring extending along the inner periphery in a plane generally perpendicular to the wall of the coolant passage at that location. The main flow of liquid coolant moving in each such individual passage during turbine operation under the combined influence of centrifugal and Coriolis forces is broken up and dispersed over an enlarged area of the interior of the coolant passage upon encountering the protrusions.

Abstract: A method is provided for fabricating complex composite components for water-cooled, high temperature gas turbines. Each component comprises a core, a thermally conducting layer of copper bonded to the core, metal tubing through which water may pass embedded in and bonded to the layer, and a corrosion resistant cladding. The method utilizes powder metallurgy techniques to form the thermally conducting layer and hot isostatic pressure to bond the corrosion resistant cladding spar and tubes to said layer.