A gas turbine engine includes a first combustor having a first fuel nozzle, wherein the first fuel nozzle is configured to supply a water fuel emulsion into the first combustor. The water fuel emulsion includes a water-in-fuel (WIF) emulsion having a plurality of water droplets dispersed in a fuel, wherein the plurality of water droplets is configured to vaporize within the fuel to cause micro-explosions to atomize the fuel, and the atomized fuel is configured to combust to generate a combustion gas. The gas turbine engine further includes a turbine driven by the combustion gas from the first combustor.

Methods and systems for starting an aircraft gas turbine engine are described. The method comprises, in a first phase of a startup upon receipt of a start request, modifying a first set of engine control parameters to cause light-up; in a second phase of the startup, modifying a second set of engine control parameters to set conditions for light-around; and in a third phase of the startup, modifying a third set of engine control parameters to propagate a flame around a combustor of the gas turbine engine.

A fuel injector includes a fuel nozzle configured to issue a spray of fuel from a fuel outlet in a downstream direction along an injection axis. The fuel nozzle defines a main flow passage therethrough. An injection fuel line is in fluid communication with the fuel nozzle to supply fuel to the fuel nozzle. A torch ignitor has a flame outlet opening into the main flow passage of the fuel nozzle for issuing flame into the main flow passage.

A method of producing compressed air for use onboard an aircraft includes receiving compressor discharge air into an air channel of a fuel injector. The method also includes cooling the compressor discharge air within the air channel by heat exchange with fuel flowing in the fuel injector, and issuing cooled air from the internal air channel out of an engine case as a source of compressed air.

An embodiment of a combustor for a gas turbine engine includes a combustor case, a combustor liner disposed within the combustor case, a fuel nozzle, and a torch igniter within the combustor case. The torch igniter includes a combustion chamber, a cap defining the upstream end of the combustion chamber and configured to receive a fuel injector and a surface igniter, a tip defining the downstream end of the combustion chamber, an annular igniter wall extending from the cap to the tip and defining a radial extent of the combustion chamber, a structural wall coaxial with and surrounding the igniter wall, and an outlet passage within the tip that fluidly connects the combustion chamber to the combustor. The torch igniter is situated such that the tip is mounted through the combustor liner, the combustion chamber is within the combustor case, and the cap extends through the combustor case.

A method of servicing a gas turbine engine having an igniter socket, the method comprising: inserting a glow plug into the igniter socket of the gas turbine engine until a rod end of a glow plug heater rod of the glow plug is exposed to a combustion chamber of the gas turbine engine; and blocking a gap between the glow plug heater rod and an aperture defined in a combustor liner of the gas turbine engine to block fluid communication between the combustion chamber and an environment outside the combustion chamber via the aperture.

An ignition system for igniting fuel in a gas turbine engine includes a power supply and an energy storage network electrically connected to the power supply. The energy storage network includes a first stage having a first capacitor and a second stage having a second capacitor. The ignition system further includes an engine igniter electrically coupled to the energy storage network.

Methods and systems for starting an engine are provided. A cold-start request to start the engine in a first operating condition associated with a predetermined engine temperature range is obtained. In response to obtaining the cold-start request, an amount of boost fuel to provide to the engine is determined, based on at least one second operating condition of the engine. The engine is started by supplementing a baseline fuel flow to the engine with the amount of boost fuel.

An engine assembly includes a combustor, a fuel cell stack integrated with the combustor, and a pre-burner system fluidly connected to the fuel cell stack. The fuel cell stack is configured to direct fuel and air exhaust from the fuel cell stack into the combustor. The pre-burner system is configured to control a temperature of an air flow directed into the fuel cell stack. The combustor is configured to combust the fuel and air exhaust from the fuel cell stack into one or more gaseous combustion products that drive a downstream turbine. The engine assembly can further include a catalytic partial oxidation convertor that is fluidly connected to the fuel cell stack. The catalytic partial oxidation convertor is configured to develop a hydrogen rich fuel stream to be directed into the fuel cell stack.

A gas turbine engine has: a casing; a combustor liner delimiting a combustion chamber; a fuel nozzle in fluid communication with the combustion chamber; and an igniter having a base, a glow plug heater rod extending from the base along an axis and terminating in a rod end, and a sleeve extending around the glow plug heater rod, the sleeve radially spaced apart from the glow plug heater rod by an annular gap, the sleeve defines fins circumferentially distributed around the axis, each two circumferentially adjacent fins of the fins spaced apart from one another by a spacing communicating with the annular gap, the fins extending in a direction having an axial component from roots to tips, the roots axially closer to the base than the tips, the rod end extending axially beyond the tips of the fins such that the rod end is located outside the annular gap.