Abstract: A method for tuning a gas turbine engine includes performing a sensitivity step process on a tuning parameter. An operating parameter is monitored. The gas turbine is operating in a first operational state and the operating parameter has an initial condition. The tuning parameter is selected for adjustment. The tuning parameter is adjusted by a predefined amount. The adjustment includes applying an incremental bias adjustment to a fuel flow fraction schedule. The gas turbine engine transitions to a second operational state, wherein the operating parameter has an adjusted condition. The adjusted condition and the initial condition of the operating parameter are applied to a cost function. It is then determined that the cost function results in a cost function value indicative of a decreased cost. The incremental bias adjustment and the cost function value is written to a bias look-up table and are associated with the selected tuning parameter.

Abstract: A radially flexible connection joint for a gas turbine engine includes an exhaust manifold flange operatively coupling an exhaust cylinder to an exhaust manifold of the gas turbine engine. The exhaust cylinder includes a cylindrical flange that extends radially outwardly from a rotation axis of the gas turbine. The cylindrical flange defines a downstream axial face. The exhaust manifold is positioned downstream from the exhaust cylinder. The exhaust manifold includes an upstream edge. The exhaust cylinder and the exhaust manifold are substantially coaxial with the rotation axis of the gas turbine. The exhaust manifold flange has a bellows portion that extends radially between the cylindrical flange of the exhaust cylinder and the upstream edge of the exhaust manifold. The bellows portion permits relative radial motion of the exhaust cylinder and the exhaust manifold.

Abstract: Modular assemblies for gas turbine engines such as modular vane assemblies and methods of manufacturing the same. The modular assembly includes a first modular component such as a vane platform having a first mating pocket, and a second modular such as an airfoil. The second modular component includes circumferentially extending first and second surfaces at first and second distal ends thereof, respectively, with the first surface being received within the first pocket when the modular assembly is in the assembled state. The second modular component also includes a coating pocket extending from the first surface to the second surface. The coating pocket is recessed towards an interior of the second modular component with respect to first surface and the second surface, and a thermal barrier coating is included within the coating pocket and not included on the first surface or the surface.

Abstract: A method is disclosed for controlling fuel injection in a reheat combustor of a gas turbine combustor assembly including a combustor casing defining a gas flow channel and a plurality of injection nozzles distributed in or around the gas flow channel; the method includes the step of distributing fuel among the injection nozzles according to a non-uniform distribution pattern.

Abstract: A method for manufacturing and heat treating a component formed from an alloy or superalloy. The component may be part of a gas turbine engine, such as an airfoil of a gas turbine engine turbine, or a combustor fuel nozzle, that includes internal cooling passages. At least part of the component is formed from the alloy or superalloy using an additive manufacturing process. The method includes determining an incipient melting point range and a recrystallization temperature of the alloy or superalloy. The component is then heated to at least the recrystallization temperature and within the incipient melting point range for a predetermined time, and ultimately cooled.

Abstract: A diffusion cartridge assembly for a gas turbine engine, and methods of using the same. The diffusion cartridge assembly includes a tip plate with an array of fuel supply openings and a mounting hole radially inward of the array of fuel supply openings, an end cover, and an outer sleeve extending from the tip plate to the end cover and defining an open inner chamber. A fuel supply line is coupled to the end cover and extends within the open inner chamber toward the tip plate. A manifold is coupled to an end of the fuel supply line proximate to the tip plate, and includes an array of fuel injector tips. Each of the fuel injector tips extends through a respective one of the array of fuel supply openings in the tip plate. The manifold also includes a thermally free mounting pin extending into the mounting hole.

Abstract: Embodiments for controlling a gas turbine engine to minimize combustion dynamics and emissions are disclosed. Methods and an apparatus are provided for controlling the gas turbine engine where a compressor inlet temperature is measured and a turbine reference temperature is calculated in real-time and utilized to determine the most-efficient fuel splits and operating conditions for each of the fuel circuits. The fuel flow for the fuel circuits are then adjusted according to the identified fuel split.

Abstract: Embodiments for minimizing relative thermal growth within a fuel nozzle of a gas turbine combustor are disclosed. Fuel nozzle configurations are provided in which a heating fluid is provided to one or more passages in a fuel nozzle from feed holes in the fuel nozzle base. The heating fluid passes through the fuel nozzle, thereby raising the operating temperature of portions of the fuel nozzle to reduce differences in thermal gradients within the fuel nozzle. Various fuel nozzle configurations and passageway geometries are also disclosed.

Abstract: Embodiments for an apparatus and associated method for reducing the residence time in a gas turbine combustor are disclosed. The embodiments of the present invention comprise a fuel nozzle that extends to a downstream plane of an end cap for a combustion liner where the axial distance of the premixer is reduced, however the swirl for mixing the fuel and air, is increased. As a result, the mixing of the fuel and air is essentially unchanged, thereby allowing higher air pressures and operating temperatures within the premixer without inducing auto-ignition.

Abstract: An inlet bleed heat and power augmentation system utilizing a bi-directional and common piping arrangement is disclosed. The piping arrangement includes a plurality of feed tubes arranged to communicate either steam to a compressor discharge plenum or compressed air from the compressor discharge plenum. Various embodiments of the invention are discussed including operation methods.

Abstract: A system and method for reducing vibration and wear to adjacent platform surfaces and mounting locations of a vane segment in a gas turbine engine is disclosed. The present invention seeks to improve the interaction between mating faces of adjacent gas turbine vane assemblies by increasing the surface area where contact between the adjacent vanes occurs, so as to increase the damping capability and reduce the wear to the mating surfaces.

Abstract: An apparatus and method of providing a gas turbine combustor having increased combustion stability and reducing pressure drop across a gas turbine combustor is disclosed. A plurality of vanes is fixed to a flow sleeve radially between the flow sleeve and a combustion liner. The plurality of vanes serve to direct a flow of air entering the region between the flow sleeve and combustion liner in a substantially axial direction, such that components of tangential velocity are removed thereby providing a more uniform flow of air the combustion chamber and reducing the amount of pressure lost due attempting to straighten the airflow by pressure drop alone.

Abstract: A transition duct having a panel assembly with an inlet end of generally circular cross section and an outlet end having a generally rectangular arc-like cross section is disclosed. The panel assembly has an uncoated internal profile substantially in accordance with coordinate values X, Y, and Z as set forth in Table 1. The coordinates are taken at a sweep angle ? wherein ? is an angle measured from the inlet end and X, Y, and Z are coordinates defining the panel assembly profile at each angle ? from the inlet end. An alternate embodiment is also disclosed defining an envelope for the uncoated internal profile of the panel assembly.

Abstract: A gas turbine combustor having a self-purging pilot fuel injection system and method of operation thereof is disclosed. The pilot fuel injection system comprises a radial inflow swirler, a generally axially extending centerbody, and at least one fuel injection source. In operation a fluid containing at least air passes along the centerbody outer surface clearing any remaining fuel from proximate the fuel injection source so as to prevent flame attachment proximate the fuel injection source.

Abstract: A fuel supply system and method thereof that utilizes an off-gas in addition to the primary fuel to lower the emissions of a gas turbine combustion system is disclosed. The fuel supply system apparatus comprises a fuel gas supply conduit and an off-gas supply conduit in fluid communication with the fuel gas supply conduit such that the flow of an off-gas to the fuel gas supply conduit can be regulated as required by the operator to the desired fuel nozzle(s). The fuel gas supply preferably operates with natural gas and the off-gas supply preferably comprises the constituents hydrogen and methane.

Abstract: Embodiments for controlling a gas turbine engine to minimize combustion dynamics and emissions are disclosed. Methods and an apparatus are provided for controlling the gas turbine engine where a compressor inlet temperature is measured and a turbine reference temperature is calculated in real-time and utilized to determine the most-efficient fuel splits and operating conditions for each of the fuel circuits. The fuel flow for the fuel circuits are then adjusted according to the identified fuel split.

Abstract: Embodiments for minimizing relative thermal growth within a fuel nozzle of a gas turbine combustor are disclosed. Fuel nozzle configurations are provided in which a heating fluid is provided to one or more passages in a fuel nozzle from feed holes in the fuel nozzle base. The heating fluid passes through the fuel nozzle, thereby raising the operating temperature of portions of the fuel nozzle to reduce differences in thermal gradients within the fuel nozzle. Various fuel nozzle configurations and passageway geometries are also disclosed.

Abstract: Embodiments for an apparatus and associated method for providing a cooling fluid to a gas turbine transition duct in order to lower the effective operating temperatures of the transition duct are disclosed. The transition duct has an inner liner and an impingement sleeve positioned radially outward with a passageway formed therebetween. The impingement sleeve has a plurality of openings where a portion of the openings each have a feed tube extending through the opening and into the passageway. The feed tubes are oriented at an angle relative to the impingement sleeve, such that an inlet to the feed tube is directed generally towards an oncoming flow of cooling fluid. The feed tubes direct a portion of the cooling fluid toward the inner liner and into the passageway for cooling of the transition duct.

Abstract: Embodiments for an apparatus and associated method for reducing the residence time in a gas turbine combustor are disclosed. The embodiments of the present invention comprise a fuel nozzle that extends to a downstream plane of an end cap for a combustion liner where the axial distance of the premixer is reduced, however the swirl for mixing the fuel and air, is increased. As a result, the mixing of the fuel and air is essentially unchanged, thereby allowing higher air pressures and operating temperatures within the premixer without inducing auto-ignition.

Abstract: A gas turbine combustor having improved flashback margin is disclosed. Multiple embodiments of the present invention are disclosed including combustors having a single premix chamber as well as multiple premix chambers. Flashback margin is increased for the combustor by incorporating a means for introducing an inert gas, such as nitrogen, into the premix chamber(s) at the region proximate the boundary layer to purge the boundary layer of combustible mixture, thereby ensuring that no combustion reaction occurs in the boundary layer.