The rotary airfoil 100 defines a cross section and a span, wherein the cross section is a function of the point along the span (e.g., spanwise point) and defines an upper surface and a lower surface at each spanwise point. The rotary airfoil 100 also defines, at a cross section, a lift coefficient (C.sub.L) that is a function of the angle of attack at which the airfoil is rotated through the air. The system can optionally include: a rotor hub to mount the rotary airfoil, a tilt mechanism to pivot the rotary airfoil between a forward configuration and a hover configuration, and a pitching mechanism to change the angle of attack of the rotary airfoil 100.

Air acceleration at leading edge of aircraft wing. In one embodiment, a slat disposed along a leading edge of a wing of an aircraft. The slat includes a skin structure having an aerodynamic shape, and a hollow space within the skin structure. The slat further includes a nozzle disposed on the skin structure to accelerate air collected in the hollow space into an external environment outside the slat to increase lift and reduce drag for the wing.

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.

A shock wave suppression device is configured to suppress a shock wave generated on a blade surface of a blade, the shock wave suppression device including a bump cover provided to follow the blade surface and deformable to protrude outward from the blade surface, and a displacing unit configured to displace the bump cover between a steady state to follow the blade surface and a deformed state to protrude outward from the blade surface. The bump cover has a curved shape in the deformed state configured to be a continuous surface from an upstream side to a downstream side in a flow direction of a fluid flowing through the blade surface.

The rotary airfoil 100 defines a cross section and a span, wherein the cross section is a function of the point along the span (e.g., spanwise point) and defines an upper surface and a lower surface at each spanwise point. The rotary airfoil 100 also defines, at a cross section, a lift coefficient (C.sub.L) that is a function of the angle of attack at which the airfoil is rotated through the air. The system can optionally include: a rotor hub to mount the rotary airfoil, a tilt mechanism to pivot the rotary airfoil between a forward configuration and a hover configuration, and a pitching mechanism to change the angle of attack of the rotary airfoil 100.

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 sleeve connecting a blade to the hub of a rotor of a rotary wing aircraft. The sleeve has a leading edge and a trailing edge, together with a protuberance arranged on the trailing edge. The dimensions of the protuberance are linked to the dimensions of the sleeve. The presence of the protuberance serves to improve the aerodynamic behavior of the sleeve and of the rotor during rotation of the rotor while the aircraft is moving forwards, both when the sleeve is advancing and when it is retreating. The presence of the protuberance also serves to reduce the vibration generated by a wake of the rotor on a tail boom or on a horizontal and/or vertical stabilizer of the aircraft.

An airflow profiled structure having a profiled leading edge. The profiled leading edge having, along a leading edge line, a serrated profile line with a succession of teeth and depressions. The airflow profiled structure also includes a porous acoustically absorbent region located towards the bottom of the depressions.

An airfoil body may include a plurality of tubercles along a leading edge of the airfoil body and a plurality of crenulations along a trailing edge of the airfoil body, wherein at least one of a position, a size, and a shape of the plurality of tubercles and the plurality of crenulations varies in a non-periodic fashion. The non-periodic fashion may be according to a Fibonacci function and may mimic the configuration of a pectoral fin of a humpback whale. The tubercles and crenulations may be defined with respect to a pivot point. The spanwise profile, including the max chord trailing edge curvature, may closely follow divine spirals and related Fibonacci proportions. The spanwise chord thickness may vary in a nonlinear pattern. Related methods are also described.