Abstract: Combustor systems are provided. For example, a combustor system comprises a combustor having forward and aft ends and including annular inner and outer liners that each extend generally along an axial direction and define a combustion chamber therebetween. The combustor system also comprises a fuel nozzle having an outlet defined in an outlet end of the fuel nozzle and including a pilot swirler. The outlet is positioned at the forward end of the combustor to direct a fuel-air mixture into the combustion chamber. The combustor system further comprises a main mixer attached to the outlet end of the fuel nozzle and extending about the outlet. A total combustor airflow through the combustor comprises a pilot swirler airflow that is greater than about 14% of the total combustor airflow and a main mixer airflow that is less than about 50% of the total combustor airflow.

Abstract: Combustor systems are provided. For example, a combustor system comprises a combustor having forward and aft ends and including annular inner and outer liners that each extend generally along an axial direction and define a combustion chamber therebetween. The combustor system also comprises a fuel nozzle having an outlet defined in an outlet end of the fuel nozzle and including a pilot swirler. The outlet is positioned at the forward end of the combustor to direct a fuel-air mixture into the combustion chamber. The combustor system further comprises a main mixer attached to the outlet end of the fuel nozzle and extending about the outlet. A total combustor airflow through the combustor comprises a pilot swirler airflow that is greater than about 14% of the total combustor airflow and a main mixer airflow that is less than about 50% of the total combustor airflow.

Abstract: The present disclosure is directed to a combustor assembly for a gas turbine engine comprising a fuel nozzle and an annular shroud. The fuel nozzle comprises a centerbody extended along a lengthwise direction. The fuel nozzle defines a nozzle centerline extended through the centerbody of the fuel nozzle along the lengthwise direction. The fuel nozzle defines a plurality of exit openings in circumferential arrangement on the centerbody relative to the nozzle centerline. The annular shroud surrounds the centerbody of the fuel nozzle. At least a portion of the shroud defines a contoured structure defining a waveform.

Abstract: A gas turbine engine combuslor has a trapped dual vortex cavity defined between aft, forward, and bottom walls. Air injection first holes are positioned in the forward wall. Air injection second holes are positioned in the aft walls. Fuel injection holes in the forward wall are located between the bottom wall and a cavity opening located at a top of the cavity. First angled film cooling apertures are disposed through the bottom wall. Second angled film cooling apertures are located in the forward wall between the fuel injection holes and the bottom wall. Third angled film cooling apertures are located in the forward wall between the fuel injection holes and the cavity opening.

Abstract: A gas turbine combustor liner, including a shell having a first end adjacent to an upstream end of the combustor and a second end adjacent to a downstream end of the combustor, where the shell also has a hot side, a cold side, and a centerline axis therethrough. A plurality of small, closely-spaced film cooling holes are formed in the shell through which air flows for providing a cooling film along the hot side of the shell. Each cooling hole has a non-uniform diameter as it extends through the shell. In particular, each cooling hole includes a first opening located at the cold side of the shell having a first diameter and a second opening located at the hot side of the shell having a second diameter, wherein the second diameter of the second opening is larger than the first diameter of the first opening. It is preferred that the shape of each cooling hole be substantially frusto-conical.

Abstract: A gas turbine engine combustor can downstream of a pre-mixer has a pre-mixer flowpath therein and circumferentially spaced apart swirling vanes disposed across the pre-mixer flowpath. A primary fuel injector is positioned for injecting fuel into the pre-mixer flowpath. A combustion chamber surrounded by an annular combustor liner disposed in supply flow communication with the pre-mixer. An annular trapped dual vortex cavity located at an upstream end of the combustor liner is defined between an annular aft wall, an annular forward wall, and a circular radially outer wall formed therebetween. A cavity opening at a radially inner end of the cavity is spaced apart from the radially outer wall. Air injection first holes are disposed through the forward wall and air injection second holes are disposed through the aft wall. Fuel injection holes are disposed through at least one of the forward and aft walls.

Abstract: A liner for a gas turbine engine combustor having a trapped vortex cavity formed therein, wherein a dome plate is positioned at an upstream end of the combustor, includes: a first portion positioned adjacent and connected to the dome plate, wherein the first liner portion extends downstream from and substantially perpendicular to the dome plate; a second portion extending substantially perpendicular to the first liner portion and substantially parallel to the dome plate; a first arcuate portion having a predetermined radius located between the first and second liner portions; a third portion extending downstream and substantially perpendicular to the second liner portion; and, a second arcuate portion located between the second and third liner portions; wherein the first liner portion, the second liner portion, the first arcuate liner portion and a portion of the dome plate form the trapped vortex cavity.

Abstract: A gas turbine engine combustor inlet diffuser assembly has at least one diverging annular wall including a flowpath surface bounding a diffuser flowpath. An annular blowing slot is axially located along the annular wall and an annular blowing air flowpath leads to and is in fluid communication with the blowing slot. An annular array of scoops disposed in the diffuser flowpath downstream of the blowing slot have upstream facing openings and are in fluid communication with the blowing air flowpath. The annular scoops are supported on hollow struts. Each of the hollow struts has at least one radially extending flow passage for directing blowing air from the scoop to the blowing air flowpath. The blowing slot opens in a downstream direction with respect to the diffuser flowpath. A row of blowing air compressor blades disposed across the blowing air flowpath may be used to pump up the pressure of the blowing air.

Abstract: A gas turbine engine combustor can downstream of a pre-mixer has a pre-mixer flowpath therein and circumferentially spaced apart swirling vanes disposed across the pre-mixer flowpath. A primary fuel injector is positioned for injecting fuel into the pre-mixer flowpath. A combustion chamber surrounded by an annular combustor liner disposed in supply flow communication with the pre-mixer. An annular trapped dual vortex cavity located at an upstream end of the combustor liner is defined between an annular aft wall, an annular forward wall, and a circular radially outer wall formed therebetween. A cavity opening at a radially inner end of the cavity is spaced apart from the radially outer wall. Air injection first holes are disposed through the forward wall and air injection second holes are disposed through the aft wall. Fuel injection holes are disposed through at least one of the forward and aft walls.

Abstract: A gas turbine engine combustor inlet diffuser assembly has at least one diverging annular wall including a flowpath surface bounding a diffuser flowpath. An annular blowing slot is axially located along the annular wall and an annular blowing air flowpath leads to and is in fluid communication with the blowing slot. An annular array of scoops disposed in the diffuser flowpath downstream of the blowing slot have upstream facing openings and are in fluid communication with the blowing air flowpath. The annular scoops are supported on hollow struts. Each of the hollow struts has at least one radially extending flow passage for directing blowing air from the scoop to the blowing air flowpath. The blowing slot opens in a downstream direction with respect to the diffuser flowpath. A row of blowing air compressor blades disposed across the blowing air flowpath may be used to pump up the pressure of the blowing air.

Abstract: A gas turbine engine combustor can downstream of a pre-mixer has a pre-mixer flowpath therein and circumferentially spaced apart swirling vanes disposed across the pre-mixer flowpath. A primary fuel injector is positioned for injecting fuel into the pre-mixer flowpath. A combustion chamber surrounded by an annular combustor liner disposed in supply flow communication with the pre-mixer. An annular trapped dual vortex cavity located at an upstream end of the combustor liner is defined between an annular aft wall, an annular forward wall, and a circular radially outer wall formed therebetween. A cavity opening at a radially inner end of the cavity is spaced apart from the radially outer wall. Air injection first holes are disposed through the forward wall and air injection second holes are disposed through the aft wall. Fuel injection holes are disposed through at least one of the forward and aft walls.

Abstract: A combustor for a gas turbine engine operates with high combustion efficiency, and low nitrous oxide emissions during engine operations. The combustor includes at least one trapped vortex cavity, a fuel delivery system including two fuel circuits, and a fuel spray bar assembly. A pilot fuel circuit supplies fuel to the trapped vortex cavity and a main fuel circuit supplies fuel to the combustor. The fuel spray bar assembly includes a spray bar and a heat shield. The spray bar is sized to fit within the heat shield. The heat shield includes aerodynamically-shaped upstream and downstream sides.

Abstract: A liner for a gas turbine engine combustor having a trapped vortex cavity formed therein, wherein a dome plate is positioned at an upstream end of the combustor, includes: a first portion positioned adjacent and connected to the dome plate, wherein the first liner portion extends downstream from and substantially perpendicular to the dome plate; a second portion extending substantially perpendicular to the first liner portion and substantially parallel to the dome plate; a first arcuate portion having a predetermined radius located between the first and second liner portions; a third portion extending downstream and substantially perpendicular to the second liner portion; and, a second arcuate portion located between the second and third liner portions; wherein the first liner portion, the second liner portion, the first arcuate liner portion and a portion of the dome plate form the trapped vortex cavity.

Abstract: A combustor for a gas turbine engine operates with high combustion efficiency, and low nitrous oxide emissions during engine operations. The combustor includes at least one trapped vortex cavity, a fuel delivery system including two fuel circuits, and a fuel spray bar assembly. A pilot fuel circuit supplies fuel to the trapped vortex cavity and a main fuel circuit supplies fuel to the combustor. The fuel spray bar assembly includes a spray bar and a heat shield. The spray bar is sized to fit within the heat shield. The heat shield includes aerodynamically-shaped upstream and downstream sides.

Abstract: A combustor for a gas turbine engine operates with high combustion efficiency, and low nitrous oxide emissions during engine operations. The combustor includes at least one trapped vortex cavity, a fuel delivery system including two fuel circuits, and a fuel spray bar assembly. A pilot fuel circuit supplies fuel to the trapped vortex cavity and a main fuel circuit supplies fuel to the combustor. The fuel spray bar assembly includes a spray bar and a heat shield. The spray bar is sized to fit within the heat shield. The heat shield includes aerodynamically-shaped upstream and downstream sides.

Abstract: A combustor for a gas turbine engine operates with high combustion efficiency, and low carbon monoxide and nitrous oxide emissions during low, intermediate, and high engine power operations. The combustor includes a fuel delivery system that includes at least two fuel stages, at least one trapped vortex cavity, and at least one mixer assembly radially inward from the trapped vortex cavity. The two fuel stages include a pilot fuel circuit that supplies fuel to the trapped vortex cavity through a fuel injector assembly and a main fuel circuit that also supplies fuel to the mixer assembly with the fuel injector assembly.

Abstract: A combustor for a gas turbine engine operates with high combustion efficiency, and low carbon monoxide and nitrous oxide emissions during low, intermediate, and high engine power operations. The combustor includes a fuel delivery system that includes at least two fuel stages, at least one trapped vortex cavity, and at least one mixer assembly radially inward from the trapped vortex cavity. The two fuel stages include a pilot fuel circuit that supplies fuel to the trapped vortex cavity through a fuel injector assembly and a main fuel circuit that also supplies fuel to the mixer assembly with the fuel injector assembly.

Abstract: A combustor for a gas turbine engine operates with high combustion efficiency, and low carbon monoxide and nitrous oxide emissions during low, intermediate, and high engine power operations. The combustor includes a fuel delivery system that includes at least two fuel stages, at least one trapped vortex cavity, and at least one mixer assembly radially inward from the trapped vortex cavity. The two fuel stages include a pilot fuel circuit that supplies fuel to the trapped vortex cavity through a fuel injector assembly and a main fuel circuit that also supplies fuel to the mixer assembly with the fuel injector assembly.