A propulsion assembly includes a first torque source coupled with a first shaft and a second torque source coupled with a second shaft. A coupler selectively couples the first and second torque sources. When the first and second torque sources are coupled via the coupler, in response to a command to decouple the first torque source, an unloading operation is performed to decrease the torque output provided by the first torque source to a threshold, and when reached, the first shaft is decoupled from the coupler. When the first torque source is coupled with the coupler but the second torque source is not, in response to a command to couple the second torque source, a speed matching operation is performed to increase the speed of the second shaft to match a speed of the first shaft, and when the speeds are matched, the second shaft is coupled to the coupler.

An aircraft propulsion system and method of cooling the same are provided. The system includes a hydraulic pump, an intermittent IC engine, a hydraulic motor, an engine oil pump, and a cooling system. The intermittent IC engine drives the hydraulic pump. The hydraulic motor is powered by the hydraulic pump and drives a propulsor fan. The cooling system includes a first heat exchanger (AIR-EO HEX) and a second heat exchanger (EO-HF HEX). The AIR-EO HEX transfers heat between flows of engine oil and ambient air. The EO-HF HEX transfers heat between flows of engine oil and hydraulic fluid. The hydraulic pump provides motive force to cause the hydraulic oil to pass through the EO-HF HEX and back to the at least one hydraulic pump. The engine oil pump provides motive force to pass the engine oil to and through the AIR-EO HEX, the EO-HF HEX, and the intermittent IC engine.

In a flying object, a PCU has a plurality of operation modes in which an engine and/or a motor generator is used as a driving source for a pusher propeller. In accordance with the state of the flying object, the PCU controls the engine, a clutch, and the motor generator in one of the operation modes.

An aircraft propulsion system comprises first and second thrust producing gas turbine engines. The system comprises a controller configured to determine a required overall propulsion system thrust level, and determine an engine core power level contribution from each aircraft gas turbine engine such that the overall propulsion system produces a minimum overall noise level and meets the required overall propulsion system thrust level. In meeting the minimum overall noise level, at least the first and second gas turbine engines are operated at different engine core power settings.

An aircraft propulsion system includes a propulsive fan assembly configured for assembly into an aircraft structure, the propulsive fan assembly that includes a fan rotatable about a fan axis, an inlet duct assembly disposed within the aircraft fuselage, the inlet duct assembly that includes an upper inlet duct with an upper inlet opening and a lower inlet duct with a lower inlet opening. The upper inlet duct and the lower inlet duct merge into a common inlet duct forward of the propulsive fan assembly, and an outlet duct is disposed aft of the propulsive fan assembly.

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.

A thermal energy system for use with an aircraft includes a cooling loop and a cooler. The cooling loop includes a fluid conduit and a pump configured to move fluid through the fluid conduit to transfer heat from a heat source to the fluid in the fluid conduit to cool the heat source. The cooler includes an air-stream heat exchanger located in a duct and is in thermal communication with the fluid conduit to transfer heat between the fluid in the cooling loop and the air passing through the duct.

An assembly is provided for an aircraft. This aircraft assembly includes a carrier, a first gear system, a second gear system and an idler. The first gear system includes a first sun gear, a first ring gear and a plurality of first intermediate gears. Each of the first intermediate gears is between and is meshed with the first sun gear and the first ring gear. Each of the first intermediate gears is rotatably mounted to the carrier. The second gear system includes a second sun gear, a second ring gear and a plurality of second intermediate gears. Each of the second intermediate gears is between and is meshed with the second sun gear and the second ring gear. Each of the second intermediate gears is rotatably mounted to the carrier. The idler gear couples the first ring gear to the second ring gear.

The present disclosure relates to a hydrogen electric hybrid power plant for a hovercar. The hydrogen electric hybrid power plant comprises a first-stage duct, a transition duct and a second-stage duct. An air outlet end of the first-stage duct is connected to the second-stage duct through the transition duct. A hydrogen reactor is arranged in the first-stage duct, and the hydrogen reactor is fixed with the first-stage duct through a plurality of supporting pieces A. A primary filter screen is arranged at a front end of the first-stage duct and fixed on the first-stage duct through a hoop, so that low-altitude sundries and dust are prevented from entering the reactor. A return pipe is arranged, and the problems of oxygen supply, heat dissipation and cooling and the like of the hydrogen reactor are solved through ducted airflow. A motor power supply requirement of a ducted fan is met.

A rotary electric machine arranged as a brushless electric ring motor is described and includes a rotor that is disposed within a stator and arranged to rotate on a guide element. The rotor has a plurality of ferritic elements arranged on an outer surface, and the stator is an annular device having a plurality of electro-magnetic elements arranged on an inner portion between first and second flanges. The first and second flanges both include an annular ring that is fabricated from a non-magnetic material and has a plurality of ferromagnetic elements. The ferromagnetic elements are magnetically coupled to corresponding ones of the electro-magnetic elements to exert magnetic force on the ferritic elements of the rotor when the electro-magnetic elements are activated. The rotary electric machine may operate as a first thrust generating system that is upstream of a second thrust generating system for a turbojet engine.