Abstract: A method of operating a fuel cell assembly for an aircraft is provided. The method includes: receiving flight load predictor data for a scheduled flight of the aircraft prior to initiation of the scheduled flight of the aircraft; and reconfiguring the fuel cell assembly in response to the received flight load predictor data prior to the initiation of the scheduled flight of the aircraft, wherein reconfiguring the fuel cell assembly comprises adding or removing a fuel cell module to or from the fuel cell assembly to increase or decrease a power capacity of the fuel cell assembly.

Abstract: An environmental control system assembly is provided for an aircraft. The assembly includes: an environmental control system; a cabin airflow delivery system in airflow communication with the environmental control system for receiving a cabin inlet airflow from the environmental control system; a cabin exhaust delivery system configured to be in airflow communication with a cabin of the aircraft for receiving a cabin exhaust airflow when the environmental control system assembly is installed in the aircraft; and a fuel cell assembly in airflow communication with the cabin exhaust delivery system for receiving the cabin exhaust airflow.

Abstract: An environmental control system assembly for an aircraft is provided. The assembly includes: an environmental control system; a fuel cell assembly in electrical communication with the environmental control system for providing electrical power to the environmental control system; and a controller operably connected to the fuel cell assembly, the controller operable to modulate an amount of power generated by the fuel cell assembly and provided to the environmental control system based on load forecasting data from an ECS load forecasting module of the controller.

Abstract: A decentralized electrical power allocation system is provided. The system includes a power bus, electric power consumers, and at least two power source assemblies. Each power source assembly includes a power controller and a power source. Each power controller is configured to execute an adaptive droop control scheme so as to cause their respective power sources to output power to meet a power demand on the power bus applied by the power consumers. The power output of a given power source is controlled based at least in part on correlating a power feedback of the given power source with a droop function that represents an efficiency of the given power source to generate electrical power for a given power output. The droop functions are collaboratively defined so that one power source shares more output at lower power levels while another power source shares more output at higher power levels.

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 solid oxide fuel cell defining an outlet positioned to remove output products from the solid oxide fuel cell during operation, the method including: operating the fuel cell assembly to provide output products to a combustor of a combustion section of the gas turbine engine; and operating the fuel cell assembly, the gas turbine engine, or both such that a pressure within an anode of the solid oxide fuel cell is less than a pressure within a cathode of the solid oxide fuel cell, is less than a pressure within a combustion chamber of the gas turbine engine, or both while operating the gas turbine engine.

Abstract: A gas turbine engine includes a fuel cell assembly including a fuel cell stack and defining a fuel cell assembly operating parameter, a fuel source, and a turbomachine. The turbomachine includes a compressor section, a combustor, and a turbine section arranged in serial flow order. The combustor is configured to receive a flow of fuel from the fuel source and further configured to receive output products from the fuel cell stack. A controller is configured to perform operations including receiving data indicative of system operation conditions, determining a set of fuel cell operating conditions to move the system emission output into or maintain the system emission output within an emissions range, and controlling the fuel cell assembly operating parameter according to the determined set of fuel cell operating conditions.

Abstract: A method of operating a gas turbine engine is provided. The method includes: providing a flow of a primary fuel to a combustor of a turbomachine, the turbomachine including a compressor, a turbine, and a spool rotatable with the compressor and the turbine; receiving data indicative of a spool parameter of the spool; and modifying a flow of a secondary fuel to the combustor in response to the received data indicative of the spool parameter of the spool.

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: A propulsion system is provided including: a gas turbine engine including a combustion section having a combustor; and a modular fuel cell assembly. The modular fuel cell assembly includes: a first fuel cell string comprising a first processing unit and a first fuel cell stack, the first fuel cell stack comprising a first fuel cell defining an outlet configured to provide output products from the first fuel cell to the combustor; and a second fuel cell string comprising a second processing unit and a second fuel cell stack, the second fuel cell stack comprising a second fuel cell defining an outlet configured to provide output products from the second fuel cell to the combustor.

Abstract: An anti-stall system for an aircraft may be provided, where the aircraft includes a propulsion system including a fuel cell assembly and a combustion engine, the combustion engine including a compressor section having a compressor. The anti-stall system may include at least one sensor configured to sense data indicative of at least one operating parameter indicative of a compressor stall condition of the compressor; and a controller including a processor and a memory storing instructions that when executed by the processor cause the controller to determine that the at least one operating parameter has achieved a compressor stall condition threshold and execute an anti-stall action responsive to determining that the at least one operating parameter has achieved the compression stall condition threshold. The anti-stall action may be configured to adjust at least one fuel cell parameter.

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 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 including a reformer stack extended around a combustion chamber. The reformer stack is configured to provide output products to the combustion chamber.

Abstract: A method for operating a fuel cell assembly, the fuel cell assembly including a fuel cell stack having a solid oxide fuel cell, the solid oxide fuel cell having an anode, a cathode, and an electrolyte, the method including: determining a temperature setpoint for the fuel cell stack, for output products of the fuel cell stack, or both; and controlling a volume of oxidant provided to the anode in response to the determined temperature setpoint to control a temperature of the fuel cell stack, a temperature of the output products of the fuel cell stack, or both.

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 comprising 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 gas turbine engine, wherein executing the startup sequence comprises initiating the startup sequence for the gas turbine engine; executing a startup sequence for the fuel cell assembly concurrently with, or subsequent to, initiating the startup sequence for the gas turbine engine; and operating the fuel cell assembly to provide output products to a combustion section of the gas turbine engine.

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 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 solid oxide fuel cell defining an outlet positioned to remove output products from the solid oxide fuel cell during operation, the method including: operating the fuel cell assembly to provide output products to a combustor of a combustion section of the gas turbine engine; and operating the fuel cell assembly, the gas turbine engine, or both such that a pressure within an anode of the solid oxide fuel cell is less than a pressure within a cathode of the solid oxide fuel cell, is less than a pressure within a combustion chamber of the gas turbine engine, or both while operating the gas turbine engine.

Abstract: Systems and methods including a plurality of reformer stacks extended around the combustion chamber. The reformer stacks are distributed along a length of the combustion chamber in the axial direction and configured to provide output products to the combustion chamber.

Abstract: A power source for an aircraft having an engine, the power source including: a fuel cell assembly configured to be integrated into the engine, the fuel cell assembly including: a first fuel cell group; and a second fuel cell group, wherein during a first operating condition of the power source the fuel cell assembly is configured to provide a first power output from the first fuel cell group and the second fuel cell group and during a second operating condition is further configured to provide a second power output from the first fuel cell group, the second power output being different than the first power output.

Abstract: A power source for an aircraft having a gas turbine engine, including: an electrical connection assembly; a fuel cell assembly integrated into the gas turbine engine, electrically coupled to the connection assembly and configured to provide a first power output; and an electric machine coupled to the gas turbine engine, electrically coupled to the connection assembly and configured to provide a second power output, wherein both the first power output from the fuel cell assembly and the second power output from the electric machine are provided to the connection assembly during operating of the gas turbine engine and wherein the connection assembly is electrically coupled to an aircraft electrical load.