Described herein is a blade system (10) for fans for industrial use, comprising:—a blade (12), which extends longitudinally along a first reference axis (K) and defines within it a cavity (12A), wherein said blade has a cross section with flattened profile and is oriented with a major dimension (L1) along a second reference axis (H); and—a supporting unit (14), on which said blade (12) is fixed and which is inserted within the cavity (12A) of said blade, said supporting unit (14) being designed to be connected to the rotor (2) of a fan. The system is characterized in that: said cavity (12A) of said blade (12) has a cylindrical conformation and a cross section with flattened profile and is oriented with its major dimension (L2) along said second reference axis (H); and said supporting unit (14) comprises a tubular bar (16), which has a cross section with flattened profile and is oriented with a major dimension (L3) along said second reference axis (H), or else a first tubular bar (26A) and a second tubular bar (26C) with circular cross section, which are arranged alongside one another along said second reference axis (H).

The present application discloses a blade, comprising a blade tip, a blade root, a leading edge, and a trailing edge, wherein the leading edge and the trailing edge each extend from the blade tip to the blade root; the blade may rotate around a rotation axis, and the rotation axis and a normal plane of the rotation axis perpendicularly intersect at the foot of the perpendicular; a projection of the leading edge on the normal plane along the rotation axis is a first curve, and the first curve has an even number of inflection points. The blade of the present application can reduce noise and improve aerodynamic performance when the blade rotates.

This composite-material blade formed by using a fiber-reinforced resin containing a resin and reinforcing fibers is provided with: a base material part provided on the inner surface of the composite-material blade; and a first cover part for covering the outer surface of the base material part. The base material part is formed by using a carbon fiber-reinforced resin containing a first resin and carbon fibers. The first cover part is formed from an elastic polymer fiber-reinforced resin containing a second resin and elastic polymer fibers, and has more resistance to impact than the base material part.

A ceiling fan blade is provided. The ceiling fan blade is configured to be mounted on a rotating base, and includes a main body and a blade holder connected to the main body. The blade holder is configured to be mounted on the rotating base. The main body includes a windward part arranged adjacent to a side of the main body and a plurality of air guiding structures arranged adjacent to the windward part. Each of the air guiding structures and the side of the main body that is adjacent to the windward part is 0.2 to 0.4 times of a width of the main body.

A dual window fan having a rectangular body adapted to engage a window, two fan heads pivotably engaging the body independently of each other about a vertical pivot axis from aiming directly outwardly normal to the body to aiming inwardly through a pivot angle of at least 225 angular degrees.

A boundary layer ingestion fan system for location aft of the fuselage of an aircraft is shown. It comprises a nacelle defining a duct, and a fan located within the duct. The fan comprises a hub arranged to rotate around a rotational axis and a plurality of blades attached to the hub, each of which has a span from a root at the hub defining a 0 percent span position (r.sub.hub) to a tip defining a 100 percent span position (r.sub.tip) and a plurality of span positions therebetween (r∈[r.sub.hub, r.sub.tip]). The hub has a negative hade angle (γ) with respect to the rotational axis at an axial position coincident with the leading edge of the blades.

A boundary layer ingestion fan system for location aft of the fuselage of an aircraft is shown. It comprises a nacelle defining a duct, and a fan located within the duct. The fan comprises a hub arranged to rotate around a rotational axis and a plurality of blades attached to the hub, each of which has a span from a root at the hub defining a 0 percent span position (r.sub.hub) to a tip defining a 100 percent span position (r.sub.tip) and a plurality of span positions therebetween (r∈[r.sub.hub, r.sub.tip]). A plurality of outlet guide vanes are positioned aft of the fan. An afterbody is located aft of the plurality of outlet guide vanes and which tapers to an apex having an apex angle with respect to the rotational axis of between 35 and 45 degrees.

A fan structure including a center portion, multiple fan blades, and a fixing ring is provided. The center portion includes a bottom surface and a center shaft. The center shaft is perpendicular to the bottom surface, and the direction in which the center shaft extends is an axial direction. The fan blades are mutually separated and connected to the bottom surface of the center portion and are disposed around the axial direction. Each of the fan blades has a height which is parallel to the axial direction. The fixing ring simultaneously contacts the side of the fan blades which is away from the center shaft. Along the axial direction, with the bottom surface of the center portion as a reference surface, the fixing ring is disposed at a range of 40% to 80% of the height of each of the fan blades.

A fan structure including a center portion, multiple fan blades, and a fixing ring is provided. The center portion includes a bottom surface and a center shaft. The center shaft is perpendicular to the bottom surface, and the direction in which the center shaft extends is an axial direction. The fan blades are mutually separated and connected to the bottom surface of the center portion and are disposed around the axial direction. Each of the fan blades has a height which is parallel to the axial direction. The fixing ring simultaneously contacts the side of the fan blades which is away from the center shaft. Along the axial direction, with the bottom surface of the center portion as a reference surface, the fixing ring is disposed at a range of 40% to 80% of the height of each of the fan blades.

The aspects of the disclosed embodiments are directed to a fan for displacing a fluid, which fan includes a rotor rotating around its axis of rotation and surfaces, such as blades, forming a flow when the rotor rotates. The rotor is arranged to displace fluid simultaneously with at least two different flows (F1, F2).