Abstract: A method for operating a propulsion system for an aircraft, the propulsion system including a gas turbine engine and a fuel cell assembly, the fuel cell assembly including a fuel cell stack having a fuel cell defining an outlet positioned to remove output products from the fuel cell during operation, the method including: executing a startup sequence for the fuel cell assembly, wherein executing the startup sequence for the fuel cell assembly includes initiating the startup sequence for the fuel cell assembly; executing a startup sequence for the gas turbine engine, wherein executing the startup sequence for the gas turbine engine comprises initiating the startup sequence for the gas turbine engine subsequent to initiating the startup sequence for the fuel cell assembly; and operating the fuel cell assembly to provide output products to a combustion section of the gas turbine engine.

Abstract: A gas turbine engine is provided. The gas turbine engine includes a turbomachine having a compressor section, a combustor, and a turbine section arranged in serial flow order, the turbomachine further including an outer casing and, during operation of the gas turbine engine, an exhaust gas flow from the turbine section; and a fuel cell assembly positioned within the outer casing of the turbomachine, the fuel cell assembly having a fuel cell defining an inlet positioned to receive a portion of the exhaust gas flow, an outlet positioned to provide output products directly to the exhaust gas flow, or both.

Abstract: A gas turbine engine is provided. The gas turbine engine includes a turbomachine having a compressor section, a combustor, and a turbine section arranged in serial flow order, the turbomachine further including an outer casing; a fuel cell assembly positioned within the outer casing of the turbomachine, the fuel cell assembly including a fuel cell and an output products line in fluid communication with an outlet of the fuel cell for receiving output products from the fuel cell; a fuel delivery assembly including a fuel line; and a reformer in communication with the fuel line and the output products from the fuel cell during operation of the gas turbine engine to convert a fuel flow through the fuel line to a hydrogen rich gas.

Abstract: A combustion section defines an axial direction, a radial direction, and a circumferential direction. The combustion section includes a casing that defines a diffusion chamber. A combustion liner is disposed within the diffusion chamber and defines a combustion chamber the combustion liner is spaced apart from the casing such that a passageway is defined between the combustion liner and the casing. A fuel cell assembly is disposed in the passageway. The fuel cell assembly includes a fuel cell stack that has a plurality of fuel cells each extending between an inlet end and an outlet end. The inlet end receives a flow of air and fuel and the outlet end provides output products to the combustion chamber. The fuel cell assembly further includes an electrical circuit that is electrically coupled to the plurality of fuel cells and that extends through the casing.

Abstract: A fuel cell assembly is provided, including a fuel cell stack having a fuel cell, the fuel cell having a cathode and an anode; and a multi-gas sensor configured to sense gas composition data of a flow of output products from the cathode, gas composition data of a flow of output products from the anode, gas composition data of a fluid surrounding the fuel cell, or a combination thereof to determine fuel cell leakage diagnostic information.

Abstract: A propulsion system including: a fuel cell assembly having a fuel cell defining an outlet positioned to remove output products from the fuel cell and a fuel cell assembly operating condition; a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order, the combustion section configured to receive a flow of aviation fuel from an aircraft fuel supply and further configured to receive the output products from the fuel cell; and a controller comprising memory and one or more processors, the memory storing instructions that when executed by the one or more processors cause the propulsion system to perform operations including receiving data indicative of a mid-flight flameout within the combustion section; modifying the fuel cell assembly operating condition in response to receiving data indicative of the mid-flight flameout within the combustion section; and initiating a relight of the combustion section.

Abstract: A hydrocarbon fluid containment article having a wall with a surface that is wetted by hydrocarbon fluid. The surface includes an anti-coking coating. The anti-coking coating includes a copper salt, a silver salt, or a combination thereof. A gas turbine engine component including a wall having a first surface and an anti-coking coating on the first surface of the wall that is wetted by hydrocarbon fluid. The anti-coking coating including a copper salt, a silver salt, or a combination thereof that prevents the formation of gum or coke on a surface thereon. Methods for reducing the deposition of thermal decomposition products on a wall of an article are also provided.

Abstract: A method is provided for operating a propulsion system having a gas turbine engine and a fuel cell assembly. The fuel cell assembly includes a fuel cell. The method includes: receiving gas composition data of output products from the fuel cell; and controlling operation of the fuel cell assembly, the gas turbine engine, or both in response to the received gas composition data of the output products from the fuel cell.

Abstract: A combustor for a gas turbine engine, the gas turbine engine defining a longitudinal centerline extending in a longitudinal direction, a radial direction extending orthogonally outward from the longitudinal centerline, and a circumferential direction extending concentrically around the longitudinal centerline, the combustor including: a liner at least partially defining a combustion chamber, the liner including a dilution slot in fluid communication with the combustion chamber; and one or more guides configured to redirect cooling medium into the dilution slot.

Abstract: Various embodiments include a trapped vortex combustor and a method for operating trapped vortex combustor. In one embodiment, the trapped vortex combustor comprises a trapped vortex combustion zone and at least one secondary combustion zone disposed downstream of the trapped vortex combustion zone. The trapped vortex combustion zone is operable to receive and combust a first fuel and a first air and produce a first combustion product flowing toroidally therein. The at least one secondary combustion zone is operable to receive and combust the first combustion product and at least one second injection consisting of fuel and/or air and produce at least one second combustion product therein. The combustor may reduce the residence time of the highest temperature combustion products and achieve the lower NOx emission.

Abstract: A propulsion system is provided including: a propulsor; a turbomachine operable to drive the propulsor to generate thrust during operation; a fuel cell assembly configured to add power to the propulsor, the turbomachine, or both; and a multi-gas sensor operable with the turbomachine, the fuel cell assembly, or both for sensing gas composition data of a fluid flow in or to the turbomachine, the fuel cell assembly, or both, the gas composition data comprising data indicative of at least two gases and their concentrations.

Abstract: Systems and methods include a fuel cell stack extended around a combustion chamber that is configured to provide output products to the combustion chamber to achieve at least one of late lean injection and a desired combustor gas concentration distribution. The fuel cell stack is positioned at a downstream section of the combustion chamber along an axial direction.

Abstract: A combustion section defines an axial direction, a radial direction, and a circumferential direction. The combustion section includes a casing that defines a diffusion chamber. A combustion liner is disposed within the diffusion chamber and defines a combustion chamber. The combustion liner is spaced apart from the casing such that a passageway is defined between the combustion liner and the casing. A fuel cell assembly is disposed in the passageway. The fuel cell assembly includes a fuel cell that extends between an inlet end and an outlet end. The inlet end receives a flow of air and fuel and the outlet end provides output products to the combustion chamber. The fuel cell extends at an angle between the inlet end and the outlet end relative to a radial projection line.

Abstract: A gas turbine engine is provided. The gas turbine engine includes a turbomachine having a compressor section, a combustor, and a turbine section arranged in serial flow order, the turbomachine further including an outer casing; and a fuel cell assembly positioned within the outer casing of the turbomachine, the fuel cell assembly including a fuel cell positioned aft of the combustor of the turbomachine, defining an exhaust in fluid communication with a location forward of the fuel cell to provide output products to the location, or both.

Abstract: A gas turbine engine is provided. The gas turbine engine includes a turbomachine having a turbomachine having a compressor section, a combustor, and a turbine section arranged in serial flow order, the turbomachine further including an outer casing; and a fuel cell assembly positioned within the outer casing of the turbomachine, the fuel cell assembly including a fuel cell, an inlet line in fluid communication with an inlet of the fuel cell, and an output products line in fluid communication with an outlet of the fuel cell for receiving output products from the fuel cell, wherein the inlet line is positioned to be in thermal communication with the output products during operation of the gas turbine engine.

Abstract: A gas turbine engine is provided. The gas turbine engine includes a turbomachine having a compressor section, a combustor, and a turbine section arranged in serial flow order, the turbomachine further including an outer casing; a fuel cell assembly positioned within the outer casing of the turbomachine, the fuel cell assembly including a fuel cell and an output products line in fluid communication with an outlet of the fuel cell for receiving output products from the fuel cell; a fuel delivery assembly including a fuel line; and a reformer in communication with the fuel line and the output products from the fuel cell during operation of the gas turbine engine to convert a fuel flow through the fuel line to a hydrogen rich gas.

Abstract: A gas turbine engine is provided.

Abstract: A system for an aircraft including: a fuel tank defining an interior; and a fuel cell assembly having a fuel cell defining an air outlet, wherein the air outlet of the fuel cell is in airflow communication with the interior of the fuel tank for providing an inerting airflow from the fuel cell to the interior of the fuel tank to reduce an oxygen content of the interior of the fuel tank.

Abstract: A propulsion system for an aircraft, the aircraft including an aircraft fuel supply, the propulsion system including: a turbomachine including a compressor section, a combustion section, and a turbine section arranged in serial flow order, the combustion section configured to receive a flow of aviation fuel from the aircraft fuel supply; and a fuel cell assembly including a fuel cell stack having a solid oxide fuel cell, the solid oxide fuel cell defining an outlet positioned to remove output products from the solid oxide fuel cell and provide the output products to the combustion section, the solid oxide fuel cell including a cathode; an electrolyte layer; and an anode positioned opposite the electrolyte layer from the cathode, the anode including a cermet, the cermet including less than 25% by volume nickel.

Abstract: Various embodiments include a trapped vortex combustor and a method for operating trapped vortex combustor. In one embodiment, the trapped vortex combustor comprises a trapped vortex combustion zone and at least one secondary combustion zone disposed downstream of the trapped vortex combustion zone. The trapped vortex combustion zone is operable to receive and combust a first fuel and a first air and produce a first combustion product flowing toroidally therein. The at least one secondary combustion zone is operable to receive and combust the first combustion product and at least one second injection consisting of fuel and/or air and produce at least one second combustion product therein. The combustor may reduce the residence time of the highest temperature combustion products and achieve the lower NOx emission.