A ducted fan includes a fan and a cowl having a cylindrical shape and including an introduction port configured to introduce air from a first end portion side. The fan includes a compressor blade provided on an outer circumferential side and a thrust blade provided on an inner circumferential side of the compressor blade. The cowl includes a housing portion configured to accommodate the compressor blade in an interior thereof, an outlet configured to allow air flowing through the housing portion to be blown therethrough by the compressor blade, and an inlet configured to suck air blown out. The outlet is provided inwards in a radial direction of the cowl and near the introduction port of the cowl, and the inlet is provided inwards in the radial direction of the cowl and between the outlet and the compressor blade in an axial line direction.

A method for managing the propulsive power of an aircraft, the aircraft extending longitudinally along an axis X from the rear forwards and comprising at least two lateral propulsion systems each comprising a fan, each lateral propulsion system having a fan rotation speed N2 and at least one rear propulsion system configured to ingest a boundary layer of said aircraft, the rear propulsion system comprising a fan having a fan rotation speed N3, the management system comprising, during a cruising phase P4, a step of adjusting the rotation speed N3 of the rear propulsion system according to the following formula N3=a*N2 in which a is a constant.

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.

A rotor blade for a rotary aircraft is disclosed. The rotor blade includes a body and an airflow duct extending within the body of the rotor blade. An airflow outlet of the airflow duct is located at a tip of the blade. The airflow outlet has a cross-sectional area that is equal to or greater than a cross-sectional area of the airflow duct. The rotor blade is used to mitigate brownout during flight. Air exits the rotor blade at the airflow outlet in order to disrupt a blade vortex created by rotation of the rotor blade.

A lift control device actively controls the lift force on a lifting surface. The device has a protuberance near a trailing edge of its lifting surface, which causes flow to separate from the lifting surface, generating regions of low pressure and high pressure which combine to increase the lift force on the lifting surface. The device further includes an arrangement to keep the flow attached around the protuberance or to modify the position of the protuberance in response to a command from a central controller, so as to provide an active control of the lift between a maximum value and a minimum value.

The invention discloses a lift source for an aircraft comprising a fuselage and wings, wherein first channels are formed in the wings, a plurality of first inlets are formed in upper surfaces of the wings, a plurality of first pressure ports are formed in lower surfaces of the wings and are communicated with the first inlets via the first channels; and spoiler devices are arranged in the first channels and under the effect of the spoiler devices, form high-speed fluid layers on the upper surfaces of the wings, thereby generating a pressure difference from the lower surfaces of the wings which counteracts an external fluid pressure on the upper surfaces of the wings in the opposite direction, so a lift is generated by reduction of fluid resistance when fluid flows through the upper and lower surfaces of the wings, thereby developing a high-speed aircraft with a larger lift and thrust.

A rotorcraft is provided and includes a fuselage. The fuselage includes drag generating portions, a main rotor assembly and an auxiliary propulsor having an expected propulsion efficiency. The auxiliary propulsor is disposed to ingest boundary layer flows and in wake regions associated with the drag generating portions and is provided with a corresponding increase in the expected propulsion efficiency thereof.

Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Disclosed are systems, methods, and apparatus for actively adjusting the position of one or more propeller blade treatments of a propeller blade of an aerial vehicle during operation of the aerial vehicle. For example, the propeller blade may have one or more propeller blade treatments that may be adjusted between two or more positions. Based on the position of the propeller blade treatments, the airflow over the propeller is altered, thereby altering the sound generated by the propeller when rotating. By altering the propeller blade treatments on multiple propeller blades of the aerial vehicle, the different sounds generated by the different propeller blades may effectively cancel, reduce, and/or otherwise alter the total sound generated by the aerial vehicle.

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.

The invention discloses an aircraft generating a larger thrust and lift by fluid continuity. First open channels used to extend fluid paths are formed in front parts and/or middle parts of windward sides of wings of the aircraft and extend from sides, close to the fuselage, of the wings to sides, away from the fuselage, of the wings, and the first open channels are concave channels or convex channels, so that a pressure difference in a direction identical with a moving direction is generated from back to front due to different flow speeds of fluid flowing over the windward sides of the wings in a lengthwise direction and a widthwise direction to reduce fluid resistance, and a larger pressure difference and lift are generated due to different flow speeds on the windward sides and leeward sides of the wings.