The invention relates to a nubomachine with a longitudinal axis, comprising two, respectively upstream (122) and downstream, coaxial outer propellers (122), characterised in that at least some of the blades (148) of the upstream propeller (122) comprise at least one internal air circulation chimney (150) that communicates with air-bleeding openings (152) in tire boundary layers of the blades (148). and communicates with air outflow openings (158) on the radially outer end thereof, the air-bleeding openings (152) leading to opening inlets (152a) on tire passive surfaces (156) of the blades (148). the inlets (152a) of the air-bleeding openings being radially arranged in an area (H1) contained between 10% and 45% of the radial dimension (H2) of the blades (148). measured above turd from the radial height of the blades for which the tangent of the leading edge (138) of the blades is orthogonal to the longitudinal axis, and the inlets (152a) of the air bleeding openings being arranged in an area contained between 0% and 30% of the local chord of the blades (148), measured at the level of said inlets (152a) and from the leading edges (138) of tire blades (148).

An active flow control system for generating yaw control moments for an aircraft during forward flight. The system includes right and left yaw effectors disposed proximate the right and left wingtips of the wing. A pressurized air system includes a pressurized air source and a plurality of injectors operably associated with the right and left yaw effectors that influence the path of airflow above and below the yaw effectors. Based upon which of the injectors is injecting pressurized air, the right and left yaw effectors generate no yaw control moment, generate a yaw right control moment or generate a yaw left control moment.

An aerial vehicle is provided including rotor units connected to the aerial vehicle, and a control system configured to operate at least one of the rotor units. The rotor unit includes rotor blades, wherein each rotor blade includes a surface area, and wherein an asymmetric parameter is defined, at least in part, by the relationship between the surface areas of the rotor blades. The value of the asymmetric parameter is selected such that the operation of the rotor unit: (i) moves the rotor blades such that each rotor blade produces a respective vortex and (ii) the respective vortices cause the rotor unit to produce a sound output having an energy distribution defined, at least in part, by a set of frequencies, wherein the set of frequencies includes a fundamental frequency, one or more harmonic frequencies, and one or more non-harmonic frequencies having a respective strength greater than a threshold strength.

An active flow control system for generating roll control moments for an aircraft during hover flight. The system includes right and left roll effectors disposed proximate the right and left wingtips of the wing. A pressurized air system includes a pressurized air source and a plurality of injectors operably associated with the right and left roll effectors. Based upon which of the injectors is injecting pressurized air, the right and left roll effectors generate no roll control moment, generate a roll right control moment or generate a roll left control moment.

An active flow control system for generating roll control moments for an aircraft during forward flight. The system includes right and left roll effectors disposed on a trailing edge of the wing. A pressurized air system includes a pressurized air source and a plurality of injectors operably associated with the right and left roll effectors that influence the path of airflow across the wing. Based upon which of the injectors is injecting pressurized air, the right and left roll effectors generate no roll control moment, generate a roll right control moment or generate a roll left control moment.

An active flow control system for generating pitch control moments for an aircraft during flight. The system includes a nozzle disposed proximate the aft end of the aircraft. The nozzle is configured to discharge a gas stream in the aftward direction. A pressurized air system includes a pressurized air source and one or more injectors configured to selectively inject pressurized air into the nozzle to influence the path of the gas stream. Based upon which injectors are injecting pressurized air into the nozzle, the gas stream exits the nozzle generating no pitch control moment, generating a pitch down control moment or generating a pitch up control moment.

The invention discloses a propeller-driven helicopter or airplane which comprises a fuselage and a propeller comprising a plurality of blades, wherein a plurality of pressure pipes are uniformly distributed between windward sides and leeward sides of the blades; a plurality of first inlets are formed in the windward sides and are communicated with outside via first channels in the blades and second outlets at tails of the blades; a high-pressure fluid of a low-speed fluid layer formed when a fluid flows through the leeward sides in a widthwise direction flows towards a low-pressure fluid of a high-speed fluid layer formed when the fluid flows through the first inlets, the first channels and the second outlets; and an upward pressure generated by the high-pressure fluid is opposite to a downward pressure generated by an external fluid above the windward sides, so that a fluid pressure above the propeller is decreased.

An aircraft operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a forward flight orientation. The aircraft has a blended wing body and includes an engine, a unitary lift fan system, a forced air bypass system and an exhaust system. The engine has a turboshaft mode and a turbofan mode. The lift fan system includes a ducted fan. In the VTOL orientation of the aircraft, the engine is in the turboshaft mode coupled to the lift fan system such that the engine provides rotational energy to the ducted fan generating the thrust-borne lift. In the forward flight orientation of the aircraft, the engine is in the turbofan mode coupled to the forced air bypass system such that the bypass air combines with the engine exhaust in the exhaust system to provide forward thrust generating the wing-borne lift.

An active flow control system for generating yaw control moments for an aircraft during forward flight. The system includes right and left yaw effectors disposed proximate the right and left wingtips of the wing. A pressurized air system includes a pressurized air source and a plurality of injectors operably associated with the right and left yaw effectors that influence the path of airflow above and below the yaw effectors. Based upon which of the injectors is injecting pressurized air, the right and left yaw effectors generate no yaw control moment, generate a yaw right control moment or generate a yaw left control moment.

An aircraft operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a forward flight orientation. The aircraft has a blended wing body and includes an engine, a binary lift fan system, a forced air bypass system and an exhaust system. The engine has a turboshaft mode and a turbofan mode. The lift fan system includes a plurality of ducted fans in a tandem lateral orientation. In the VTOL orientation of the aircraft, the engine is in the turboshaft mode coupled to the lift fan system such that the engine provides rotational energy to the ducted fans generating the thrust-borne lift. In the forward flight orientation of the aircraft, the engine is in the turbofan mode coupled to the forced air bypass system such that the bypass air combines with the engine exhaust in the exhaust system to provide forward thrust generating the wing-borne lift.