Abstract: A fuel nozzle includes a center body that extends from an upstream end to a downstream end. A nozzle tip, which is fixedly coupled to the downstream end of the center body, includes an outer annular wall that has a forward end and an aft end. A solid aft wall is disposed at the aft end of the outer annular wall. The solid aft wall and the outer annular wall at least partially define a plenum. A nozzle portion, which is disposed within the plenum, includes an inner annular wall and an impingement wall. The impingement wall is spaced apart from the solid aft wall and defines a plurality of apertures configured to direct fluid to impinge upon the solid aft wall. A plurality of outlets is defined in the outer annular wall forward of the solid aft wall to direct post-impingement fluid from the nozzle tip.

Abstract: A cartridge tip includes a main body having an outer annular wall and an inner core each extending between a respective upstream end and a respective downstream end. The inner core is radially spaced apart from the outer annular wall such that an annular air passage is defined at least partially between the outer annular wall and the inner core. A pilot fuel circuit extends between a pilot inlet defined in the upstream end of the inner core and a pilot outlet defined in a downstream end of the inner core. The pilot fuel circuit extends at least partially along an axial centerline of the cartridge tip. A main fuel circuit extends between a main inlet in the upstream end of the inner core and a plurality of main outlets circumferentially spaced apart from one another and disposed upstream from the from the pilot outlet.

Abstract: Sealing arrangements and turbomachines are provided. A sealing arrangement includes a transition duct having an upstream end and a downstream end. The transition duct includes an aft frame that circumferentially surrounds the downstream end of the transition duct. A first stage nozzle is spaced apart from the aft frame and defines a gap therebetween. A sealing assembly is coupled to the aft frame. The sealing assembly includes a flexible sealing element that extends from the aft frame, across the gap, to the first stage nozzle. The flexible sealing element is forced into sealing engagement with the first stage nozzle by pressure from a compressed working fluid. The sealing assembly further includes a heat shield disposed between the flexible sealing element and the aft frame. The heat shield terminates within the gap.

Abstract: Combustors and gas turbines are provided. A combustor includes an axial centerline and an end cover. The combustor further includes at least one fuel nozzle that extends from the end cover and at is least partially surrounded by a combustion liner. The combustion liner extends between the at least one fuel nozzle and an aft frame and that defines a combustion chamber. An outer sleeve is spaced apart from and surrounds the combustion liner such that an annulus is defined therebetween. The outer sleeve defines at least one aperture. A wake energizer is mounted on the outer sleeve. The wake energizer defines at least one passage that is angled with respect to the axial centerline of the combustor. The at least one passage aligns and is in fluid communication with the at least one aperture of the outer sleeve.

Abstract: An igniter for a combustor of a turbomachine includes a fuel inlet in fluid communication with a mixing plenum. The mixing plenum is positioned upstream of a mixing channel. An air inlet is in fluid communication with the mixing plenum and an ignition source is in operative communication with the mixing channel. The igniter may include a mounting flange configured for coupling the igniter to the combustor. The ignition source may be positioned proximate to a downstream end of the mixing channel and upstream of the mounting flange. The mixing channel may define a venturi shape. The venturi shape includes a converging section between an upstream end of the mixing channel and a venturi throat.

Abstract: A cartridge tip includes a main body having an outer annular wall and an inner core each extending between a respective upstream end and a respective downstream end. The inner core is radially spaced apart from the outer annular wall such that an annular air passage is defined at least partially between the outer annular wall and the inner core. A pilot fuel circuit extends between a pilot inlet defined in the upstream end of the inner core and a pilot outlet defined in a downstream end of the inner core. The pilot fuel circuit extends at least partially along an axial centerline of the cartridge tip. A main fuel circuit extends between a main inlet in the upstream end of the inner core and a plurality of main outlets circumferentially spaced apart from one another and disposed upstream from the from the pilot outlet.

Abstract: A fuel nozzle includes a center body that extends from an upstream end to a downstream end. A nozzle tip, which is fixedly coupled to the downstream end of the center body, includes an outer annular wall that has a forward end and an aft end. A solid aft wall is disposed at the aft end of the outer annular wall. The solid aft wall and the outer annular wall at least partially define a plenum. A nozzle portion, which is disposed within the plenum, includes an inner annular wall and an impingement wall. The impingement wall is spaced apart from the solid aft wall and defines a plurality of apertures configured to direct fluid to impinge upon the solid aft wall. A plurality of outlets is defined in the outer annular wall forward of the solid aft wall to direct post-impingement fluid from the nozzle tip.

Abstract: An insert for an impingement plate and an impingement plate including the insert are disclosed. The impingement plate includes a plurality of cooling holes therein. The insert includes a body including an opening extending longitudinally therethrough. The body also includes a discharge end configured for positioning in an impingement air plenum between the impingement plate and an upstream surface of a combustor cap plate; a flexible insertion end configured for insertion into a respective cooling hole of the plurality of cooling holes; and a fixation element between the discharge end and the flexible insertion end. The fixation element has an outer dimension configured to fixedly couple the body in the respective cooling hole.

Abstract: A combustor includes an end cover and at least one fuel nozzle extending from the end cover and at least partially surrounded by a combustion liner. The combustor further includes an outer sleeve spaced apart from and surrounding the combustion liner such that an annulus is defined therebetween. The combustor further includes a fuel injection assembly. The fuel injection assembly includes a fuel injector that extends through the outer sleeve, the annulus, and the combustion liner to the secondary combustion zone. A fuel supply conduit positioned outside of the outer sleeve. The fuel supply conduit extending to the fuel injector. A shielding assembly coupled to the outer sleeve and at least partially surrounding the fuel supply conduit. The at least one fuel sweep opening is defined in the outer sleeve and disposed within the shielding assembly.

Abstract: An igniter for a combustor of a turbomachine includes a fuel inlet in fluid communication with a mixing plenum. The mixing plenum is positioned upstream of a mixing channel. An air inlet is in fluid communication with the mixing plenum and an ignition source is in operative communication with the mixing channel. The igniter may include a mounting flange configured for coupling the igniter to the combustor. The ignition source may be positioned proximate to a downstream end of the mixing channel and upstream of the mounting flange. The mixing channel may define a venturi shape. The venturi shape includes a converging section between an upstream end of the mixing channel and a venturi throat.

Abstract: A combustor cap assembly, combustor and related method are disclosed. The combustor cap assembly includes: an impingement plate defining a plurality of impingement cooling holes with a first side of the impingement plate in fluid communication with a cooling air plenum. The assembly also includes a combustor cap plate coupled to the impingement plate, such that an impingement air plenum is defined between a second side of the impingement plate and the combustor cap plate. Tubes extend from at least a portion of the plurality of impingement cooling holes at the second side of the impingement plate and extend partially towards the combustor cap plate through the impingement air plenum. The plurality of impingement cooling holes provides for fluid communication between the cooling air plenum and the impingement air plenum through the tubes.

Abstract: Combustors and gas turbines are provided. A combustor includes an axial centerline and an end cover. The combustor further includes at least one fuel nozzle that extends from the end cover and at is least partially surrounded by a combustion liner. The combustion liner extends between the at least one fuel nozzle and an aft frame and that defines a combustion chamber. An outer sleeve is spaced apart from and surrounds the combustion liner such that an annulus is defined therebetween. The outer sleeve defines at least one aperture. A wake energizer is mounted on the outer sleeve. The wake energizer defines at least one passage that is angled with respect to the axial centerline of the combustor. The at least one passage aligns and is in fluid communication with the at least one aperture of the outer sleeve.

Abstract: A combustor includes at least one fuel nozzle extending from the end cover and at least partially surrounded by the forward casing. The combustor further includes a fuel injection assembly. The fuel injection assembly includes a fuel injector that extends through the outer sleeve, the annulus, and the combustion liner to the secondary combustion zone. A fuel supply conduit positioned outside of the outer sleeve. The fuel supply conduit extends to the fuel injector. The fuel injection assembly further includes a shielding assembly coupled to the outer sleeve and at least partially surrounding the fuel supply conduit. The shielding assembly includes a venturi nozzle having a circumferentially converging portion and a circumferentially diverging portion. At least one fuel sweep opening is defined in the outer sleeve and disposed within the shielding assembly.

Abstract: An object includes an annular outer body having an end and an interior surface; a first annular inner body disposed inside the annular outer body, the first annular inner body having an exterior surface defining a first annular passage with the interior surface of the annular outer body. The first annular passage includes a first plurality of outlets formed on the end of the annular outer body, the first annular passage receiving a coolant and discharging the coolant adjacent the end of the annular outer body. The object also includes a second annular inner body disposed inside the first annular inner body, the second annular inner body defining a second annular passage with the first annular inner body. Further, the object includes a third annular inner body disposed inside the second annular inner body, with the third annular inner body defining a third annular passage with the second annular inner body; and a fourth annular passage opposite and surrounded by the third annular passage.

Abstract: Sealing arrangements and turbomachines are provided. A sealing arrangement includes a transition duct having an upstream end and a downstream end. The transition duct includes an aft frame that circumferentially surrounds the downstream end of the transition duct. A first stage nozzle is spaced apart from the aft frame and defines a gap therebetween. A sealing assembly is coupled to the aft frame. The sealing assembly includes a flexible sealing element that extends from the aft frame, across the gap, to the first stage nozzle. The flexible sealing element is forced into sealing engagement with the first stage nozzle by pressure from a compressed working fluid. The sealing assembly further includes a heat shield disposed between the flexible sealing element and the aft frame. The heat shield terminates within the gap.

Abstract: An insert for an impingement plate and an impingement plate including the insert are disclosed. The impingement plate includes a plurality of cooling holes therein. The insert includes a body including an opening extending longitudinally therethrough. The body also includes a discharge end configured for positioning in an impingement air plenum between the impingement plate and an upstream surface of a combustor cap plate; a flexible insertion end configured for insertion into a respective cooling hole of the plurality of cooling holes; and a fixation element between the discharge end and the flexible insertion end. The fixation element has an outer dimension configured to fixedly couple the body in the respective cooling hole.

Abstract: A combustor cap assembly, combustor and related method are disclosed. The combustor cap assembly includes: an impingement plate defining a plurality of impingement cooling holes with a first side of the impingement plate in fluid communication with a cooling air plenum. The assembly also includes a combustor cap plate coupled to the impingement plate, such that an impingement air plenum is defined between a second side of the impingement plate and the combustor cap plate. Tubes extend from at least a portion of the plurality of impingement cooling holes at the second side of the impingement plate and extend partially towards the combustor cap plate through the impingement air plenum. The plurality of impingement cooling holes provides for fluid communication between the cooling air plenum and the impingement air plenum through the tubes.

Abstract: A gas turbine includes a compressor, a turbine, and a combustor disposed downstream from the compressor and upstream from the turbine. The combustor includes an end cover. The combustor also includes a flange. The flange includes an internal fluid passage defined within the flange and the flange is coupled to an internal face of the end cover. A fuel port is integrally joined with the flange. The fuel port extends through the end cover between the flange and an inlet positioned outside of the end cover. The inlet of the fuel port is in fluid communication with the internal fluid passage of the flange.

Abstract: A sealing arrangement includes a transition duct having an aft frame that circumferentially surrounds the downstream end of the transition duct. The aft frame defines a cooling circuit that has an outlet configured to direct cooling air in a radial direction. A first stage nozzle is spaced apart from the aft frame and defines a gap therebetween. A sealing assembly that extend circumferentially along at least a portion of the aft frame and is coupled to the aft frame. The sealing assembly includes a flexible sealing element that extends from the aft frame, across the gap, to the first stage nozzle. The flexible sealing element is forced into sealing engagement with the first stage nozzle by pressure from a compressed working fluid. A cooling flow director that is disposed between the outlet of the cooling circuit and the flexible sealing element.

Abstract: Combustors, gas turbines, and associated methods of operation are provided. A method for operating a combustor includes firing a bundled tube fuel nozzle assembly within a combustion liner of the combustor to generate combustion gases at a first temperature within a first combustion zone length. The method further includes firing a fuel injector downstream from the bundled tube fuel nozzle assembly within the combustion liner of the combustor to generate combustion gases at a second temperature within a second combustion zone length. The first combustion zone length is less than the second combustion zone length. The combustion gases travel through the first combustion zone length in a first time period and through the second combustion zone length in a second time period. The second time period is less than the first time period.