A hydraulic propulsion system is disclosed which includes an input interface configured to receive mechanical power from a power source, a pressure source comprising one or more fixed or variable displacement pumps coupled to the input interface and adaptable to convert mechanical power to hydraulic power and controlling outlet pressure of the pressure source (system pressure), one or more variable displacement motors coupled to the pressure source via a corresponding high-pressure line configured to be mechanically coupled to one or more aerodynamic rotors of an aircraft and comprising a closed loop speed control arrangement in response to a commanded rotor speed, and a controller configured to control the speed of one or more variable displacement motors by providing a control signal for controlling the system pressure.

A propulsion system, comprising: a fan blade housing; a plurality of fan blades within the fan blade housing; one or more rows of permanent magnets, affixed to the outside of the fan blade housing; one or more fan blade bearings; one or more magnetic field generators affixed to the one or more fan blade bearings and corresponding to the one or more rows of permanent magnets, the magnetic field generators configured to cause the permanent magnets to be propelled forward in the same direction, thereby causing the fan blade housing to which they are attached, and the fan blades within, to spin.

A propulsion system, comprising: a fan blade housing; a plurality of fan blades within the fan blade housing; one or more rows of permanent magnets, affixed to the outside of the fan blade housing; one or more fan blade bearings; one or more magnetic field generators affixed to the one or more fan blade bearings and corresponding to the one or more rows of permanent magnets, the magnetic field generators configured to cause the permanent magnets to be propelled forward in the same direction, thereby causing the fan blade housing to which they are attached, and the fan blades within, to spin.

A ducted fan assembly includes a duct having an inlet, an inner surface, an expanding diffuser and an outlet. A fan disposed within the duct between the inlet and the expanding diffuser is configured to rotate about a fan axis to generate airflow. An active flow control system includes a plurality of injection zones circumferentially distributed about the inner surface. The expanding diffuser has a diffuser angle configured to create flow separation when the airflow is uninfluenced by the active flow control system such that the airflow has a thrust vector with a first direction that is substantially parallel to the fan axis. Injection of pressurized air from one of the injection zones asymmetrically reduces the flow separation between the airflow and the expanding diffuser downstream of that injection zone such that the thrust vector of the airflow has a second direction that is not parallel to the first direction.

A ducted fan assembly includes a duct having an inlet, an inner surface, an expanding diffuser and an outlet. A fan disposed within the duct between the inlet and the expanding diffuser is configured to rotate about a fan axis to generate airflow. An active flow control system includes a plurality of injection zones circumferentially distributed about the inner surface. The expanding diffuser has a diffuser angle configured to create flow separation when the airflow is uninfluenced by the active flow control system such that the airflow has a thrust vector with a first direction that is substantially parallel to the fan axis. Injection of pressurized air from one of the injection zones asymmetrically reduces the flow separation between the airflow and the expanding diffuser downstream of that injection zone such that the thrust vector of the airflow has a second direction that is not parallel to the first direction.

A hybrid multirotor propulsion system for an aircraft includes a plurality of propulsion units, each propulsion unit having a propeller, an electromotor and a peripheral differential gearbox; a plurality of driving elements, each of which is coupled to a respective one of the plurality of propulsion units; a mechanical power source; a main distributor gearbox; at least one electric machine; and a power management unit. The power management unit is configured according to a predetermined operating mode, which causes the mechanical power source to output first and second mechanical power components; and distributing the first mechanical power component to provide each driving element with a direct mechanical propeller power; and causes the electric machine to convert the second mechanical power component into electric power, part of which provides each electromotor with an electric propeller power. The direct mechanical propeller power causes each electromotor to convert the electric propeller power into an indirect mechanical propeller power, outputted to the peripheral differential gearbox; and causes the peripheral differential gearbox of each propulsion unit to aggregate the direct mechanical propeller power and the indirect mechanical propeller power to a total mechanical propeller power which drives the propeller of each propulsion unit.

A hybrid multirotor propulsion system for an aircraft includes a plurality of propulsion units, each propulsion unit having a propeller, an electromotor and a peripheral differential gearbox; a plurality of driving elements, each of which is coupled to a respective one of the plurality of propulsion units; a mechanical power source; a main distributor gearbox; at least one electric machine; and a power management unit. The power management unit is configured according to a predetermined operating mode, which causes the mechanical power source to output first and second mechanical power components; and distributing the first mechanical power component to provide each driving element with a direct mechanical propeller power; and causes the electric machine to convert the second mechanical power component into electric power, part of which provides each electromotor with an electric propeller power. The direct mechanical propeller power causes each electromotor to convert the electric propeller power into an indirect mechanical propeller power, outputted to the peripheral differential gearbox; and causes the peripheral differential gearbox of each propulsion unit to aggregate the direct mechanical propeller power and the indirect mechanical propeller power to a total mechanical propeller power which drives the propeller of each propulsion unit.

Systems and methods relate to a vertical takeoff and landing (VTOL) platform that can include a stator and a rotor magnetically levitated by the stator. The rotor and stator can be annular, such that the rotor rotates about a rotational axis. The stator can include magnets that provide guidance, levitation, and drive forces to drive the rotor, as well as to control operation of rotor blades of the rotor that can be independently rotated to specific pitch angles to control at least one of lift, pitch, roll, or yaw of the VTOL platform. Various controllers can be used to enable independent and redundant control of components of the VTOL platform.

Systems and methods relate to a vertical takeoff and landing (VTOL) platform that can include a stator and a rotor magnetically levitated by the stator. The rotor and stator can be annular, such that the rotor rotates about a rotational axis. The stator can include magnets that provide guidance, levitation, and drive forces to drive the rotor, as well as to control operation of rotor blades of the rotor that can be independently rotated to specific pitch angles to control at least one of lift, pitch, roll, or yaw of the VTOL platform. Various controllers can be used to enable independent and redundant control of components of the VTOL platform.

A turboshaft engine for a rotorcraft includes a first spool and an independently rotatable second spool. The first spool includes a low pressure compressor, a first set of variable guide vanes disposed at an entry of the low pressure compressor, and a low pressure turbine drivingly engaged to the low pressure compressor. The second spool includes a high pressure compressor, a second set of variable guide vanes disposed at an entry of the high pressure compressor, the second set of variable guide vanes independently operable relative to the first set of variable guide vanes, and a high pressure turbine drivingly engaged to the high pressure compressor. One or both of the low pressure compressor and the high pressure compressor includes a mixed flow rotor.