Abstract: Examples described herein provide a computer-implemented method for managing battery usage for a hybrid electric engine of an aircraft. The method includes receiving a flight plan comprising flight plan data for a flight of an aircraft. The method further includes receiving battery data about a battery system of the aircraft. The method further includes determining waypoints for when to apply electric power from the battery system based at least in part on the flight plan data and the battery data. The method further includes controlling, based at least in part on the waypoints, an electric motor while the flight plan is executed. The method further includes updating, while the flight plan is executed, the waypoints based at least in part on data received during the flight.

Abstract: A method of operating an aircraft hybrid gas turbofan during an idle mode of operation includes reducing a fuel flow to a primary gas turbine engine and boosting a high spool of the primary gas turbine engine using a secondary gas turbine engine via a first power linkage connecting the primary and secondary gas turbine engines, such that a net fuel reduction is achieved. The net fuel reduction accounts for fuel flow to the primary gas turbine engine and fuel flow to the secondary gas turbine engine.

Abstract: Examples described herein provide a computer-implemented method that includes providing the hybrid electric engine, the hybrid electric engine having a gas generating core and an electric machine powered by electric energy. The method further includes determining, by a processing device, whether a use of the electric energy will increase time on wing of the hybrid electric engine of the aircraft a threshold amount. The method further includes, responsive to determining that the use of energy will increase time on wing the threshold amount, apportioning the electric energy from a battery system of the aircraft to increase the time on wing.

Abstract: A gas turbine engine includes a turbine section located at an engine central longitudinal axis, a combustor configured to drive rotation of the turbine with combustion products, and a compressor section coupled to the turbine section at the engine central longitudinal axis and driven by the turbine section. An auxiliary compressor is located fluidly between the compressor section and the combustor such that an airflow exiting the compressor section is directed toward the auxiliary compressor. The auxiliary compressor is driven independently from the compressor section and is configured to output the airflow toward the combustor.

Abstract: A gas turbine engine includes a turbine section located at an engine central longitudinal axis, a combustor configured to drive rotation of the turbine with combustion products, and a compressor section coupled to the turbine section at the engine central longitudinal axis and driven by the turbine section. An auxiliary compressor is located fluidly between the compressor section and the combustor such that an airflow exiting the compressor section is directed toward the auxiliary compressor. The auxiliary compressor is driven independently from the compressor section and is configured to output the airflow toward the combustor.

Abstract: Examples described herein provide a computer-implemented method that includes providing the hybrid electric engine, the hybrid electric engine having a gas generating core and an electric machine powered by electric energy. The method further includes determining, by a processing device, whether a use of the electric energy will increase time on wing of the hybrid electric engine of the aircraft a threshold amount. The method further includes, responsive to determining that the use of energy will increase time on wing the threshold amount, apportioning the electric energy from a battery system of the aircraft to increase the time on wing.

Abstract: A method for active bi-directional control of an outer structure of a gas turbine engine comprises sending, by a controller, a first control signal to a power electronics for varying an electric current supplied to a heating element to cause the outer structure to move in a first radial direction, and sending, by the controller, a second control signal to a valve assembly for varying a cooling air flow supplied to the outer structure to cause the outer structure to move in a second radial direction. The first radial direction is opposite the second radial direction.

Abstract: A gas turbine engine includes a compressor. A turbine is mechanically connected to the compressor by a shaft. An air-driven auxiliary turbine is in fluid communication with the compressor and is configured to receive pressurized air from the compressor. An auxiliary generator is operably connected to the auxiliary turbine. The auxiliary generator is configured to generate electrical energy in response to an operation of the auxiliary turbine. An energy storage device is in electrical communication with the auxiliary generator.

Abstract: An aspect includes a method of variable cycle compensation in a gas turbine engine. An electric component can be adjusted to compensate for a power change induced by an actuation system by operating the electric component as an electric motor to compensate for an increase in power absorption or a decrease in power production of a turbomachinery of the gas turbine engine. The actuation system is configured to adjust a variable cycle of the turbomachinery by adjusting power absorption or power production, and the electric component can be configured to add or subtract torque to a shaft of the gas turbine engine. The electric component can be operated as an electric generator to compensate for an increase in power production or a decrease in power absorption of the turbomachinery.

Abstract: An aircraft propulsion system includes a fan section that includes a fan shaft that is rotatable about a fan axis. The fan shaft includes a fan gear. The aircraft propulsion system also includes a boost turbine engine that includes a first output shaft that includes a first gear that is coupled to the fan gear. The boost turbine engine has a first maximum power capacity. The aircraft propulsion system further includes a cruise gas turbine engine that includes a second output shaft that includes a second gear that is coupled to the fan gear. The cruise turbine engine has a second maximum power capacity that is less than the first maximum power capacity of the boost turbine engine. The fan section produces a thrust that corresponds to power input through the fan gear from the boost turbine engine and the cruise turbine engine.

Abstract: A system includes a gas turbine engine of an aircraft, the gas turbine engine having a low speed spool, a high speed spool, and a combustor. The system also includes a low spool motor configured to augment rotational power of the low speed spool and a high spool motor configured to augment rotational power of the high speed spool. The system further includes a controller configured to cause fuel flow. The controller is configured to control a thrust response of the gas turbine engine to a thrust target between zero and a thrust level to move the aircraft during engine start and during engine idle. The controller is also configured to control the low spool motor to drive rotation of the low speed spool responsive to a thrust command while the controller does not command fuel flow to the combustor.

Abstract: A method for active bi-directional control of an outer structure of a gas turbine engine comprises sending, by a controller, a first control signal to a power electronics for varying an electric current supplied to a heating element to cause the outer structure to move in a first radial direction, and sending, by the controller, a second control signal to a valve assembly for varying a cooling air flow supplied to the outer structure to cause the outer structure to move in a second radial direction. The first radial direction is opposite the second radial direction.

Abstract: A disclosed drive assembly for an auxiliary power unit includes a first drive shaft driven by an auxiliary power unit, a second drive shaft driven by a first electric motor, a differential gear system including a ring gear driven by the second drive shaft, a and planet gears supported within a carrier attached to the ring gear. The first drive shaft and an output shaft are coupled to the planet gears and a generator is driven by the output shaft. The electric motor and the auxiliary power unit combine to drive the output shaft.

Abstract: A hybrid electric gas turbine engine system includes a first compressor and an auxiliary compressor. The first compressor is configured to output first compressed air. The auxiliary compressor is configured to operate in parallel with the first compressor to output second compressed air. A controller is configured to selectively activate the first compressor or the auxiliary compressor based on an operating condition of the hybrid electric gas turbine engine system.

Abstract: Examples described herein provide a computer-implemented method that includes providing the hybrid electric engine, the hybrid electric engine having a gas generating core and an electric machine powered by electric energy. The method further includes determining, by a processing device, whether a use of the electric energy will increase time on wing of the hybrid electric engine of the aircraft a threshold amount. The method further includes, responsive to determining that the use of energy will increase time on wing the threshold amount, apportioning the electric energy from a battery system of the aircraft to increase the time on wing.

Abstract: A power system of an aircraft includes a hybrid energy storage system with at least two energy storage subsystems each having a different power-energy density. The power system also includes one or more electric motors operably coupled to the hybrid energy storage system and to an aircraft engine. The power system further includes a means for controlling one or more electric power flows of the hybrid energy storage system to/from the one or more electric motors based on a modeled electric power demand associated with an engine load of one or more spools of the aircraft engine.

Abstract: A system of a hybrid aircraft includes a first gas turbine engine including a fan, a high speed spool, and a low spool motor configured to drive rotation of the fan. The system also includes a second gas turbine engine and a controller. The controller is operable to determine an operating mode of the hybrid aircraft, control the low spool motor to drive rotation of the fan of the first gas turbine engine responsive to a thrust command while the second gas turbine engine is driven by commanding fuel combustion based on the operating mode, and accelerate the high speed spool of the first gas turbine engine and command fuel combustion at the first gas turbine engine based on a transition of the operating mode to perform a starting operation of the first gas turbine engine.

Abstract: A system includes a gas turbine engine having a low speed spool, a high speed spool, and a combustor. The system also includes a low spool motor configured to augment rotational power of the low speed spool. The system further includes a controller configured to cause fuel flow. The controller is operable to control the low spool motor to drive rotation of the low speed spool responsive to a thrust command while the controller does not command fuel flow to the combustor.

Abstract: An aspect includes a hybrid gas turbine engine system of a hybrid electric aircraft. The hybrid gas turbine engine system includes a gas turbine engine having a low speed spool and a high speed spool, a generator operably coupled to the low speed spool, a high spool electric motor operably coupled to the high speed spool, and a controller. The controller is configured to control the hybrid gas turbine engine system in a powered warm-up state to add heat to one or more components of the gas turbine engine by operating the gas turbine engine with a higher engine power setting above idle to drive rotation of the generator, transfer power from the generator to the high spool electric motor, and produce thrust. The gas turbine engine transitions from the powered warm-up state after reaching a target temperature of the one or more components in the powered warm-up state.

Abstract: A hybrid electric engine of an aircraft includes a compressor, a turbine operably connected to the compressor via a variable gear ratio gearbox and a combustor configured to drive the turbine via a flow of combustion products. An electric motor is operably connected to the variable gear ratio rear box and configured to input rotational energy into the gearbox. The input of rotational energy into the gearbox from the electric motor changes a rotational speed of one of the compressor or the turbine relative to the other of the compressor or the turbine.