Abstract: A gas turbine engine is provided. The gas turbine engine includes a turbomachine defining an engine inlet to an inlet duct, a fan duct inlet to a fan duct, and a core inlet to a core duct; a primary fan driven by the turbomachine; and a secondary fan located downstream of the primary fan within the inlet duct. The gas turbine engine defines a thrust to power airflow ratio between 3.5 and 100 and a core bypass ratio between 0.1 and 10, wherein the thrust to power airflow ratio is a ratio of an airflow through a bypass passage over the turbomachine plus an airflow through the fan duct to an airflow through the core duct, and wherein the core bypass ratio is a ratio of the airflow through the fan duct to the airflow through the core duct.

Abstract: An electrical machine includes a stator assembly coupled to an engine stator component of a propulsion engine. The stator assembly includes a stator support assembly fixedly attached to the engine stator component and a stator disposed on a supporting surface of the stator support structure. The electrical machine also includes a rotor assembly including a rotor support structure connected to a shaft of the propulsion engine and a rotor attached to the rotor support structure such that the rotor is disposed radially inward of the stator. The rotor exchanges rotational energy with the shaft to operate as either an electrical motor or an electrical generator.

Abstract: A method for operating an electric machine assembly is provided. The electric machine assembly includes an electric machine having a first set of windings and a second set of windings. The method includes: operating the electric machine in a partial phase mode, wherein operating the electric machine in the partial phase mode comprises: powering a first set of windings to provide a net zero current in the first set of windings while maintaining one phase of the first set of windings in a non-conducting condition; and powering a second set of windings to provide a net zero current in the second set of windings while maintaining one phase of the second set of windings in a non-conducting condition.

Abstract: An AC electrical system for a vehicle and methods of operating the same are provided. In one aspect, an AC electrical system includes a first electric machine mechanically coupled with a first spool of a gas turbine engine and a second electric machine mechanically coupled with a second spool of the gas turbine engine. The system also includes a first AC bus and a second AC bus. A first electrical channel electrically couples the first electric machine to the first AC bus and a second electrical channel electrically couples the second electric machine to the second AC bus. The system also includes one or more connection links and one or more power converters for selectively electrically coupling the first and second electrical channels so that electrical power generated by one electric machine can be converted and shared with the other electric machine and electrical loads of the other channel.

Abstract: A power source assembly is provided having a fuel cell module configured to provide a first direct current power output; a battery module configured to provide a second direct current power output; a direct current electric bus configured to provide a net direct current power output to a load; a DC/DC converter in electrical connection with the direct current electric bus, the DC/DC converter configured to receive the first direct current power output from the fuel cell module or the second direct current power output from the battery module; and a controller operably coupled to the DC/DC converter and configured to receive data indicative of the first direct current power output, the controller configured to control the DC/DC converter based on the data indicative of the first direct current power output to maintain a slew rate from the fuel cell module within a slew rate range.

Abstract: An electric power system for a vehicle includes at least one electric machine, one or more power rectifiers, and a plurality of DC channels. The at least one electric machine includes a plurality of tooth-wound multi-phase windings that are substantially magnetically decoupled, and the at least one electric machine is mechanically balanced even if one of the plurality of windings is de-energized. The one or more power rectifiers are configured to produce rectified power from the power generated by the at least one electric machine. The plurality of DC channels are formed after the at least one power rectifier and are configured to provide DC power to one or more loads within a vehicle.

Abstract: Broadly speaking, the present disclosure describes a method of modeling a temporal point process (TPP). For each sequence in the TPP, the method treats the sequence as one of a plurality of distinct tasks, and applies meta learning to the distinct tasks. Applying meta learning to the distinct tasks may comprise applying a neural process to the distinct tasks; the neural process may be an attentive neural process.

Abstract: An electric propulsor is provided. The electric propulsor includes a core cowl and an outer cowl. A first air flowpath is defined radially outward of the outer cowl and a second air flowpath is defined between the core cowl and the outer cowl. The electric propulsor also includes one or more electric machines, a fan rotatably drivable by at least one electric machine, and a booster having a plurality of airfoils disposed at least in part in the second air flowpath, the booster being rotatably drivable by at least one electric machine for compressing air flowing along the second air flowpath. The electric propulsor further includes a heat exchanger disposed within the second air flowpath downstream of the booster, the heat exchanger being in thermal communication with at least one of the one or more electric machines and/or a gearbox mechanically coupled with the fan.

Abstract: A system for energy conversion including a closed cycle engine containing a volume of working fluid is provided. The engine includes a double-ended piston assembly including a pair of pistons coupled to a connection member. An expansion chamber is separated from a compression chamber by the piston. The engine defines an outer end and an inner end relative to a lateral extension of the piston assembly. A heater body is positioned thermally proximal to the expansion chamber and thermally distal to the compression chamber, and the heater body is positioned at the outer end of the engine. A load device is operably coupled to the piston assembly at the inner end of the engine. The load device is positioned between the pair of pistons of the piston assembly.

Abstract: A rotor of an electric machine is provided. The rotor includes a plurality of laminates arranged along an axial direction, the plurality of laminates including a first laminate having: a body formed of a first material, the first material being a ferromagnetic material; and a structural element formed integrally with the body of a second material, the second material being a non-ferromagnetic material.

Abstract: A method is provided of generating electric power with an electric machine. The method includes rotating a rotor of the electric machine relative to a stator of the electric machine with a shaft of a gas turbine engine during an operating condition of the gas turbine engine, the gas turbine engine being a three-stream gas turbine engine defining an axial direction, the three-stream gas turbine engine comprising: the shaft, a primary fan operatively coupled with the shaft, a mid-fan positioned downstream of the primary fan and operatively coupled with the shaft, a low pressure turbine operatively coupled with the shaft, wherein rotating the rotor of the electric machine relative to the stator of the electric machine comprises generating an electric machine power during the operating condition and generating a low pressure turbine power during the operating condition.

Abstract: An electric power system for a vehicle includes one or more power conversion systems electrically connected in parallel for each phase of an electric motor of an electric drive system. Each power conversion system is electrically coupled to a set of energy storage modules from among a plurality of energy storage modules of an energy storage pack. Each power conversion systems includes a power circuit and a power controller. The power circuit is electrically coupled to a respective set of energy storage modules and configured to provide a drive power output to the electric drive system and an auxiliary power output to a power bus. The power controller is configured to control the power circuit to provide the drive power output based on a desired power output of the electric drive system.

Abstract: A vehicle includes a gas turbine engine having at least two spools and an associated power system. The power system includes two independent power subsystems, including a first power subsystem for managing power transfer between spools and a second power subsystem for supplying a base power load to the vehicle. The first power subsystem has a first electric machine mechanically coupled with a first spool of the gas turbine engine and a second electric machine mechanically coupled with a second spool. The second electric machine is electrically coupled with the first electric machine such that electrical power is transmittable therebetween. The second power subsystem has a third electric machine mechanically coupled with one of the spools. The third electric machine is electrically coupled with a load positioned offboard the gas turbine engine. The first power subsystem and the second power subsystem are electrically decoupled from one another.

Abstract: A stator core is provided that can define a plurality of core slots in a surface thereof. The core slots can extend between a first and a second end portion of the stator core. A winding can be housed in the core slots. The winding can define a channel through at least a portion thereof. A cooling system can be operably coupled with the channel and can be configured to move a cooling fluid through the channel. A turbulator can be positioned within the channel. The turbulator can be within a flowpath of the cooling fluid and can be integrally formed with the winding.

Abstract: A method of electrically insulating a conductive component for an electric machine includes applying a first dielectric material, by dispersion coating, to the conductive component to define a first dielectric coating. The method also includes applying a second dielectric material, by electrostatic coating, to define a second dielectric coating. The first dielectric coating and the second dielectric coating can then be cured.

Abstract: An electric propulsor is provided. The electric propulsor includes a core cowl and an outer cowl. A first air flowpath is defined radially outward of the outer cowl and a second air flowpath is defined between the core cowl and the outer cowl. The electric propulsor also includes one or more electric machines, a fan rotatably drivable by at least one electric machine, and a booster having a plurality of airfoils disposed at least in part in the second air flowpath, the booster being rotatably drivable by at least one electric machine for compressing air flowing along the second air flowpath. The electric propulsor further includes a heat exchanger disposed within the second air flowpath downstream of the booster, the heat exchanger being in thermal communication with at least one of the one or more electric machines and/or a gearbox mechanically coupled with the fan.

Abstract: A vehicle includes a gas turbine engine having at least two spools and an associated power system. The power system includes two independent power subsystems, including a first power subsystem for managing power transfer between spools and a second power subsystem for supplying a base power load to the vehicle. The first power subsystem has a first electric machine mechanically coupled with a first spool of the gas turbine engine and a second electric machine mechanically coupled with a second spool. The second electric machine is electrically coupled with the first electric machine such that electrical power is transmittable therebetween. The second power subsystem has a third electric machine mechanically coupled with one of the spools. The third electric machine is electrically coupled with a load positioned offboard the gas turbine engine. The first power subsystem and the second power subsystem are electrically decoupled from one another.

Abstract: A vehicle includes a gas turbine engine having at least two spools and an associated power system. The power system includes two independent power subsystems, including a first power subsystem for managing power transfer between spools and a second power subsystem for supplying a base power load to the vehicle. The first power subsystem has a first electric machine mechanically coupled with a first spool of the gas turbine engine and a second electric machine mechanically coupled with a second spool. The second electric machine is electrically coupled with the first electric machine such that electrical power is transmittable therebetween. The second power subsystem has a third electric machine mechanically coupled with one of the spools. The third electric machine is electrically coupled with a load positioned offboard the gas turbine engine. The first power subsystem and the second power subsystem are electrically decoupled from one another.

Abstract: An electric power conversion system comprising: an alternating current (AC) source comprising a plurality of AC terminals for conducting AC power; a voltage source electrically coupled to the AC terminals; and a controller operably coupled to the voltage source, the controller being configured to: operate the voltage source to apply a fault reducing voltage at the AC terminals that reduces an AC line-to-line fault current (If).

Abstract: An electrical machine includes a stator assembly coupled to an engine stator component of a propulsion engine. The stator assembly includes a stator support assembly fixedly attached to the engine stator component and a stator disposed on a supporting surface of the stator support structure. The electrical machine also includes a rotor assembly including a rotor support structure connected to a shaft of the propulsion engine and a rotor attached to the rotor support structure such that the rotor is disposed radially inward of the stator. The rotor exchanges rotational energy with the shaft to operate as either an electrical motor or an electrical generator.