The invention relates to a profiled structure elongated in a direction in which the structure has a length exposed to an airflow and transversely to which the structure has a leading edge and/or a trailing edge, at least one of which is profiled and has, along said direction of elongation, geometric serration patterns defined by a succession of peaks and troughs. Along the profiled leading edge and/or trailing edge, the serration patterns have a geometric pattern that is repeated in the direction of elongation, the shape of which is stretched and/or contracted transversely to the direction of elongation and/or in the direction of elongation.

The invention relates to a profiled structure elongated in a direction in which the structure has a length exposed to an airflow and transversely to which the structure has a leading edge and/or a trailing edge, at least one of which is profiled and has, along said direction of elongation, geometric serration patterns defined by a succession of peaks and troughs. Along the profiled leading edge and/or trailing edge, the serration patterns have a geometric pattern that is repeated in the direction of elongation, the shape of which is stretched and/or contracted transversely to the direction of elongation and/or in the direction of elongation.

An aero wind power generation apparatus includes: a drone unit including drone wings configured to make the aero wind power generation apparatus move and hover and a sensor unit configured to detect information for controlling the aero wind power generation apparatus; a buoyancy generation unit connected to the drone unit and including a side cover configured to open or close and a balloon provided inside the side cover, wherein the buoyancy generation unit is configured to enable injection of gas into or release of the gas from the balloon; and a power generation unit connected to the buoyancy generation unit and including a rotating unit with a plurality of blades, a blade control unit of adjusting the state of the blades, and a motor unit of converting kinetic energy transferred from the rotating unit into electrical energy.

An aero wind power generation apparatus includes: a drone unit including drone wings configured to make the aero wind power generation apparatus move and hover and a sensor unit configured to detect information for controlling the aero wind power generation apparatus; a buoyancy generation unit connected to the drone unit and including a side cover configured to open or close and a balloon provided inside the side cover, wherein the buoyancy generation unit is configured to enable injection of gas into or release of the gas from the balloon; and a power generation unit connected to the buoyancy generation unit and including a rotating unit with a plurality of blades, a blade control unit of adjusting the state of the blades, and a motor unit of converting kinetic energy transferred from the rotating unit into electrical energy.

A propeller includes a blade free to rotate. A first stop is positioned to mechanically engage one or both of a first portion of the blade and a first structure coupled to the blade when the blade is in a first position at a first end of the rotational range of motion. A second stop is positioned to mechanically engage one or both of a second portion of the blade and a second structure coupled to the blade when the blade is in a second position at a second end of the defined rotational range. The blade rotates to the first position against the first stop when the propeller is rotated in a first direction and to the second position against the second stop when the propeller is rotated in a second direction.

A propeller includes a blade free to rotate. A first stop is positioned to mechanically engage one or both of a first portion of the blade and a first structure coupled to the blade when the blade is in a first position at a first end of the rotational range of motion. A second stop is positioned to mechanically engage one or both of a second portion of the blade and a second structure coupled to the blade when the blade is in a second position at a second end of the defined rotational range. The blade rotates to the first position against the first stop when the propeller is rotated in a first direction and to the second position against the second stop when the propeller is rotated in a second direction.

Techniques for deicing propellers for mobile platforms are disclosed. In one embodiment, a system is provided. The system may include a propeller comprising a propeller blade having a channel extending from an ingress aperture to an egress aperture along a longitudinal axis of the propeller blade. The system may further include a cowl comprising an air duct configured to direct heated air into the channel to deice the propeller blade. The cowl may be configured to selectively couple to the propeller and an electric motor and form a seal between the cowl and the electric motor to capture the heated air exuded by the electric motor. Additional systems and methods are also disclosed.

A disc-type vertical take-off and landing aircraft includes the following. A skirt widens toward the bottom. A disc-shaped rotor is positioned on a lower side of the skirt and rotates with relation to the skirt. A plurality of blades are provided standing on an upper surface of the rotor and are positioned radially from a center of the rotor. A cutout is formed in each of the plurality of blades. When the rotor rotates, centrifugal force causes an airflow along the blade rotating with the rotor, the airflow swirls in a spiral by a flow of air flowing over the cutout of the blade in a direction substantially orthogonal to the blade, the airflow flows in a radial direction of the rotor along the blade while swirling in the spiral, and the airflow ejected downward by the skirt causes ascending.

A disc-type vertical take-off and landing aircraft includes the following. A skirt widens toward the bottom. A disc-shaped rotor is positioned on a lower side of the skirt and rotates with relation to the skirt. A plurality of blades are provided standing on an upper surface of the rotor and are positioned radially from a center of the rotor. A cutout is formed in each of the plurality of blades. When the rotor rotates, centrifugal force causes an airflow along the blade rotating with the rotor, the airflow swirls in a spiral by a flow of air flowing over the cutout of the blade in a direction substantially orthogonal to the blade, the airflow flows in a radial direction of the rotor along the blade while swirling in the spiral, and the airflow ejected downward by the skirt causes ascending.

A method for improving performance in an aircraft having a winglet coupled to a wing, the winglet having a leading edge and a trailing edge continuously transitioning from a leading edge and trailing edge of the wing. The method includes coupling a wing tip to the winglet. The wing tip may include a curved leading edge from the winglet leading edge to a leading end point, a curved trailing edge from a winglet trailing edge to a trailing end point, and an end segment connecting the leading end point and the trailing end point. The end segment may be swept back from the trailing end point to the leading end point at an end segment angle.