Abstract: An injector for a combustor of a gas turbine engine is provided with a plurality of air/fuel mixing tubes divided into radially outer and radially inner subsets of air/fuel mixing tubes with a first fuel manifold in fluid communication with the radially outer subset of air/fuel mixing tubes and a second fuel manifold in fluid communication with the radially inner subset of air/fuel mixing tubes. Each of the air/fuel mixing tubes of the radially outer subset of air/fuel mixing tubes includes a substantially quadrilateral cross-sectional profile, and each of the air/fuel mixing tubes of the radially inner subset of air/fuel mixing tubes includes a substantially circular cross-sectional profile.

Abstract: An injector for a combustor of a gas turbine engine is provided with a plurality of first vanes radially arrayed about a central axis of the injector and a plurality of second vanes radially arrayed about the central axis of the injector and disposed radially inward of the plurality of first vanes. A plurality of fuel injection holes are disposed nearer to a trailing edge than to a leading edge of the second vanes for injecting fuel into compressed air passing through over the second vanes. The trailing edge of each of the second vanes includes a non-planar profile configured to induce turbulence in the compressed air to thereby mix the fuel with the compressed air and reduce the surfaces on which undesirable flame anchoring may occur.

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: 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: 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.

Abstract: A combustion liner having enhanced heat transfer over at least a portion of the liner is disclosed. The combustion liner comprises, amongst other features, an outer surface wherein at least a region of the outer surface is textured in a substantially uniform pattern such that the surface area exposed to a passing cooling medium is increased, thereby increasing the heat transfer through the combustion liner. Multiple embodiments of textured patterns are also disclosed.

Abstract: A seal extending between adjacent slots of a gas turbine engine is disclosed. The seal comprises a plurality of generally planar members fixed together along a central axis. The outer member further comprises rounded ends that encompass the second and plurality of third generally planar members. The seal disclosed herein improves sealing capability by providing a more compliant seal over the prior art while reducing the mechanical loads experienced along the seal weld joint, thereby improving seal durability.

Abstract: The present invention discloses an apparatus and method for reducing the carbon monoxide emissions emitted by a pilot injector of a gas turbine combustor. Multiple embodiments of a means for establishing a recirculation zone are disclosed whereby a portion of the fuel and air mixture from the pilot injector recirculates and a flame is held, thereby increasing the local reaction temperature at the desired location and lowering carbon monoxide emissions.

Abstract: A vane assembly for a gas turbine engine is disclosed having lower thermally induced stresses resulting in improved component durability. The stresses in the vane assembly airfoils are lowered by increasing the flexibility of the vane platform and reducing its resistance to thermal deflection. This is accomplished by placing an opening along the innermost vane assembly rail that reduces the effective stiffness of the platform, thereby lowering the operating stresses in the airfoils of the vane assembly. A removable seal is then placed in the opening in order to prevent undesired leakages, while maintaining the benefit of the increased platform flexibility.

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.