The present disclosure relates to a blade and a rotor of a rotor craft, and a rotor craft. The blade includes a blade root, a blade tip, and an upper aerofoil and a lower aerofoil disposed vertically opposite to each other. One sides of the upper aerofoil and the lower aerofoil are connected to form a front edge, and other sides of the upper aerofoil and the lower aerofoil are connected to form a tail edge. The upper aerofoil is defined by an upper aerofoil characteristic line formed by (kx, ky, kz) defined by a plurality of coordinate pairs. The lower aerofoil is defined by a lower aerofoil characteristic line formed by (kx, ky, kz) defined by a plurality of coordinate pairs.

A proprotor blade for a ducted aircraft including a duct includes a main body having a distal end and a sacrificial blade tip coupled to the distal end of the main body. The sacrificial blade tip includes a deformable core material and a shell layer at least partially covering the deformable core material. The sacrificial blade tip deforms upon contact with the duct, thereby reducing damage to the ducted aircraft.

A vertical take-off and landing aircraft includes a ducted rotary wing. The ducted rotary wing includes a duct and a rotary wing. The duct runs through a body from an upper surface to a lower surface thereof. The rotary wing is provided inside the duct and includes a hub and a blade configured to rotate about the hub. The blade includes a tip inlet, a trailing-edge outlet, and a trailing-edge flow path. The tip inlet is provided on a tip surface of the blade. The trailing-edge outlet is provided at a trailing edge that is an edge on a rear side in a rotation direction of the blade. The trailing-edge flow path allows the tip inlet and the trailing-edge outlet to be in communication with each other.

A wing having a wing box (20) defining a first wing profile with a first leading edge, a first trailing edge, a first top surface and a first bottom surface; a first appendage hinged on the wing box and defining a second wing profile, in turn comprising an end wall and a second trailing edge, a second top surface and a second bottom surface; the first appendage is movable between: a first position, in which the first and the second wing profiles are contiguous with each other and a second position, in which the second bottom surface and second top surface are respectively separated from the first bottom surface and first top surface; the wing box comprises a first spar having a curved section in a plane orthogonal to the associated first axis; the end wall is curved and arranged abutting against the first spar at least along the second top surface and the second bottom surface when the first movable appendage is in the first position.

A rotor blade for an aircraft includes first and second blade tips, a blade body, and a vortex-generating blade. The blade body has an end forming the first blade tip of the rotor blade and an airfoil section configured such that during rotation, pressure acting on a lower surface of the blade body is greater than pressure acting on an upper surface of the blade body. The vortex-generating blade is disposed at an end of the rotor blade and forms the second blade tip. The vortex-generating blade also has an airfoil section configured such that during rotation, pressure acting on a lower surface of the vortex-generating blade is smaller than pressure acting on an upper surface of the vortex-generating blade.

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.

Composite airfoils of the present disclosure comprise a root section including a first surface. The airfoils comprise an intermediate section having a first surface and coupled with the root section at a first end. The airfoils comprise a tip section having a first surface and coupled at a first end with a second end of the intermediate section. The airfoils comprise a conductive material layer adjacent at least one of the first surface of the root section, the first surface of the intermediate section, and the first surface of the tip section. The conductive material comprises a first polymer, a second polymer, and a sulfonic acid.

Composite airfoils of the present disclosure comprise a root section including a first surface. The airfoils comprise an intermediate section having a first surface and coupled with the root section at a first end. The airfoils comprise a tip section having a first surface and coupled at a first end with a second end of the intermediate section. The airfoils comprise a conductive material layer adjacent at least one of the first surface of the root section, the first surface of the intermediate section, and the first surface of the tip section. The conductive material comprises a first polymer, a second polymer, and a sulfonic acid.

A proprotor system for a ducted aircraft includes a duct and proprotor blades surrounded by the duct. Each proprotor blade is rotatable about a respective pitch change axis. The proprotor blades are configured to change collective pitch about the pitch change axes. The proprotor blades are extendable along the pitch change axes into various positions including a retracted position and an extended position. The proprotor blades change between the retracted position and the extended position based on the collective pitch of the proprotor blades, thereby controlling a tip gap between the proprotor blades and the duct.

A rotor for a hover-capable aircraft is described that comprises: a hub rotatable about a first axis and at least two blades hinged to the hub; each blade comprises a main portion hinged to the hub and a tip portion, which is arranged radially outermost with respect to first axis with respect to the corresponding main portion; the tip portion of each blade is movable with respect to the corresponding main portion of that blade; the tip portion of each blade is selectively movable with respect to the corresponding main portion of that blade between a first position, in which it defines a dihedral or anhedral angle with respect to the corresponding main portion; and a second position, in which it defines a positive or negative sweep angle with respect to the corresponding main portion.