A propeller having a plurality of blades extending radially outward from a hub, the blades forming a loop. Each loop having an intake portion, an exhaust portion and a tip portion extending radially outward from the hub and a gap between the intake root and the exhaust root. The tip portion of each of the blades is 30%-75% of the blade, the tip portion beginning at a first deviation from zero of the roll value and extending to 90 degrees, wherein roll value is zero in a plane parallel to the hub axis, and wherein the blades have a vertical angle between −45 degrees and 45 degrees throughout.

A propeller having a plurality of blades extending radially outward from a hub, the blades forming a loop. Each loop having an intake portion, an exhaust portion and a tip portion extending radially outward from the hub and a gap between the intake root and the exhaust root. The tip portion of each of the blades is 30%-75% of the blade, the tip portion beginning at a first deviation from zero of the roll value and extending to 90 degrees, wherein roll value is zero in a plane parallel to the hub axis, and wherein the blades have a vertical angle between −45 degrees and 45 degrees throughout.

A method for the control of a vertical take-off and landing (VTOL) aircraft which reduces the acoustic profile of the rotary airfoil in hover for VTOL applications. The rotary airfoil incurs an efficiency penalty in order to improve the acoustic performance during hover. The aircraft operates the rotary airfoils of the propeller during hover in the hover angle of attack range, and the aircraft operates the rotary airfoils during forward flight in the forward angle of attack range.

A method for the control of a vertical take-off and landing (VTOL) aircraft which reduces the acoustic profile of the rotary airfoil in hover for VTOL applications. The rotary airfoil incurs an efficiency penalty in order to improve the acoustic performance during hover. The aircraft operates the rotary airfoils of the propeller during hover in the hover angle of attack range, and the aircraft operates the rotary airfoils during forward flight in the forward angle of attack range.

A ducted axial fan. The fan includes a rotor rotatable around an axis X and having a plurality of blades, and a duct suitable for defining a circular section channel developing in an axial direction around the rotor. The duct includes an annular seat circumferentially extending around the rotor, and the blade tips are at least partially received in the annular seat of the duct.

A propeller blade having a blade body including a blade base, a blade tip, a pressure side surface, and, a suction side surface. Each of the pressure side surface and the suction side surface extend between the blade base to the blade tip. An end plate is provided on the blade body. The end plate is exposed to an airflow and positioned at the blade base. The end plate projects outwardly of at least a portion of one of the pressure side surface and the suction side surface.

A propeller blade having a blade body including a blade base, a blade tip, a pressure side surface, and, a suction side surface. Each of the pressure side surface and the suction side surface extend between the blade base to the blade tip. An end plate is provided on the blade body. The end plate is exposed to an airflow and positioned at the blade base. The end plate projects outwardly of at least a portion of one of the pressure side surface and the suction side surface.

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.

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.

A propeller blade includes a body configured to extend radially from the hub of a propeller. The body can include a front surface, a back surface, a leading edge, and a trailing edge. The top of the body can form a tippet that generally transitions the front and back surfaces from extending in a generally radial direction to a generally axial direction. The tippet can reduce radial flow and force losses, redirect the radial flow in an axial direction, reduce the exit flow area of the propeller, and increase the inlet flow area of the propeller. The front surface of the blade can have a planar configuration that prevents or reduces the creation of low or negative pressure across the front surface of the blade and associated cavitation.