A pilot burner for a combustor includes an inner conduit configured to deliver a fuel, and an outer conduit concentric with the inner conduit and configured to deliver air. An inner wall defines an inner plenum, and a partition wall is radially outward of the inner wall and defines an intermediate plenum with at least a portion of the inner wall. Exit passages fluidly couple the inner plenum to the intermediate plenum. An outer wall defines an outer plenum with at least a portion of the partition wall. A crossover section includes passages fluidly coupling the inner conduit to the outer plenum, and passages fluidly coupling the outer conduit to the inner plenum. An end plate includes openings to direct fuel, air for combustion, and air for cooling from the respective plenums.

A gas turbine engine with a compressor section, a turbine section, and a combustion section located downstream from the compressor section and upstream from the turbine section, the combustion section including: a dome inlet, a combustor outlet fluidly coupled to the turbine section, a liner and a dome assembly together at least partially defining a combustion chamber extending between the dome inlet and the combustor outlet, a primary fuel injector fluidly coupled to the dome inlet, and a second fuel injector fluidly coupled to the combustion chamber.

A gas turbine engine with a compressor section, a turbine section, and a combustion section located downstream from the compressor section and upstream from the turbine section, the combustion section including: a dome inlet, a combustor outlet fluidly coupled to the turbine section, a liner and a dome assembly together at least partially defining a combustion chamber extending between the dome inlet and the combustor outlet, a primary fuel injector fluidly coupled to the dome inlet, and a second fuel injector fluidly coupled to the combustion chamber.

A combustor for a gas turbine engine having a compressor upstream of the combustor and a turbine downstream of the combustor. The combustor also includes a combustor chamber, an oxy-fuel pilot burner (104) centrally positioned at an end of the combustor chamber, and an air-fuel premix burner configured to at least partially premix air and fuel. The air-fuel premix burner surrounds the oxy-fuel pilot burner (104) in an annular configuration.

A fuel injection system may comprise a mixer and a fuel injector disposed within the mixer. The mixer may comprise an outer housing with an exit port and a bluff body extending across the exit port of the outer housing. A flared surface of the mixer may match a contour of the bluff body.

A fuel injection system may comprise a mixer and a fuel injector disposed within the mixer. The mixer may comprise an outer housing with an exit port and a bluff body extending across the exit port of the outer housing. A flared surface of the mixer may match a contour of the bluff body.

An embodiment of a torch ignitor system for combustor of a gas turbine engine includes a torch ignitor, the torch ignitor having a combustion chamber oriented about an axis, the combustion chamber having axially upstream and downstream ends defining a flow direction through the combustion chamber, along the axis. The torch ignitor system also includes a cap defining the axially upstream end of the combustion chamber and oriented about the axis, wherein the cap is configured to receive a fuel injector and at least one glow plug, a tip at a downstream end of the combustion chamber, and a passage for pressurized oxygen containing gas passing through the cap from an exterior of the combustion chamber and in fluid communication with the combustion chamber. An embodiment of a method for starting a gas turbine engine is also disclosed.

A method of operating a combustor of a turbomachine on a total fuel input that contains a concentration of hydrogen that is greater than about 80% is provided. The method includes injecting a first mixture of air and a first fuel containing a first amount of hydrogen into the primary combustion zone of the combustor to generate a first flow of combustion gases having a first temperature. The method further includes injecting, with one or more premix injectors disposed downstream of the fuel nozzles, a second mixture of air and a second fuel containing a second amount of hydrogen into the secondary combustion zone of the combustor to generate a second flow of combustion gases having a second temperature. The method further includes separately injecting a third fuel into secondary combustion zone to generate a third flow of combustion gases having a third temperature.

A method of operating a combustor of a turbomachine on a total fuel input that contains a concentration of hydrogen that is greater than about 80% is provided. The method includes injecting a first mixture of air and a first fuel containing a first amount of hydrogen into the primary combustion zone of the combustor to generate a first flow of combustion gases having a first temperature. The method further includes injecting, with one or more premix injectors disposed downstream of the fuel nozzles, a second mixture of air and a second fuel containing a second amount of hydrogen into the secondary combustion zone of the combustor to generate a second flow of combustion gases having a second temperature. The method further includes separately injecting a third fuel into secondary combustion zone to generate a third flow of combustion gases having a third temperature.

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.