A centrifugal or diagonal impeller has impeller blades (4) that are curved in the circumferential direction about an axis of rotation and are formed from a single-layer sheet metal. Each blade (4) has a suction side (11) and a pressure side (12) as well as a blade leading edge (5) and a blade trailing edge (6). At least the blade leading edge (5) of the impeller blades (4) adjacent to their suction side (11) have a geometric edge modification in the form of a rounding (7) over a predetermined partial length of a blade thickness (SD) of the impeller blades (4).

A turbomachine includes an annular casing and a fan disposed inside the annular casing and mounted for rotation about an axial centerline. The fan includes fan blades that extend radially outwardly toward the annular casing. The fan has an average chord fan width according to a first performance factor. The fan has a quantity of fan blades according to a second performance factor.

An airfoil includes an airfoil wall that defines a leading end, a trailing end, and first and second sides that join the leading end and the trailing end. A rib connects the first and second sides of the airfoil wall. The rib defines a tube portion that circumscribes a rib passage, and first and second connector arms that solely join the tube portion to, respectively, the first and second sides of the airfoil wall.

An axial flow fan includes a hub and a blade provided around the hub and having a leading edge and a trailing edge. The blade has a thickness portion. The thickness portion includes a first thickness portion located adjacent to the leading edge and a second thickness portion located adjacent to the trailing edge. A virtual circle centered on the rotation axis and passing through both the first thickness portion and the second thickness portion of the blade is a reference circle, an intersection at which the reference circle intersects an edge portion of the first thickness portion is a first intersection, an intersection at which the reference circle intersects an edge portion of the second thickness portion is a second intersection, an intersection of the reference circle and the leading edge is a first edge portion, an intersection of the reference circle and the trailing edge is a second edge portion, a straight line passing through the rotation axis and the first intersection is a thickness portion first straight line, a straight line passing through the rotation axis and the second intersection is a thickness portion second straight line, a straight line passing through the rotation axis and the first edge portion is an edge portion first straight line, a straight line passing through the rotation axis and the second edge portion is an edge portion second straight line, an angle between the thickness portion first straight line and the edge portion first straight line is a phase angle θ1, and an angle between the thickness portion second straight line and the edge portion second straight line is a phase angle θ2. The phase angle θ1 is larger than the phase angle θ2.

A turbine blade for a gas turbine engine has an airfoil including leading and trailing edges joined by spaced-apart pressure and suction sides to provide an external airfoil surface extending from a platform in a spanwise direction to a tip. The external airfoil surface is formed in substantial conformance with multiple cross-sectional profiles of the airfoil defined by a set of Cartesian coordinates set forth in Table 1, the Cartesian coordinates provided by an axial coordinate scaled by a local axial chord, a circumferential coordinate scaled by a local axial chord, and a span location.

A curved contour of the lateral surface of a blade arrangement includes in at least one meridian section on mutually opposite sides of a blade airfoil an intersection point that is closer to the blade airfoil front edge, and an intersection point that is closer to the blade airfoil rear edge, and a best-fit line of least square distances from the curved contour. The curved contour includes first and/or the second contour section which meet specified conditions.

An impeller for a centrifugal fan rotatable about a central axis extending in an axial direction includes a hub portion expanding radially outward about the central axis, and wings on a radially outer side of the hub portion. A cross-sectional shape of the wing in a circumferential direction is a wing shape.

A stator vane provided rearward of a rotor blade, includes: an airfoil body having an airfoil profile. The maximum airfoil thickness position of the airfoil body on the airfoil profile satisfies following conditions at least on a tip side of the airfoil body: (a) on a plane expanded in a circumferential direction in which the stator vane is arranged, the position is located in a first region which is close to a trailing edge of the airfoil body from an intersection of the airfoil body and a line which is parallel to an extension line of a camber line of the rotor blade at a trailing edge of the rotor blade and passes through a leading edge of another stator vane adjacent in the circumferential direction, and (b) the position is located in a second region having a chord ratio from 0.2 to 0.8.

A ceiling fan or blade thereof can include a fan motor for rotating the blade. The blade can include an airfoil body having an outer surface extending between a leading edge and a trailing edge, and a root and a tip. The blade can be separated into three distinct cross sections including a first cross section as a lifting cross section, a second cross section as a flat cross section, and a third cross section as a transition section between the first and second cross sections.

A ceiling fan including a retention system and method of redundantly retaining a ceiling fan can include a ceiling fan motor assembly including a hollow motor shaft at least partially surrounded by a motor housing. A retainer plate is provided at the bottom of the motor housing including an opening. A retainer rod extends through the opening in the retainer plate and secures to the retainer plate. A support cable couples to the retainer rod to suspend the retainer plate from a structure, wherein the retainer plate is configured to redundantly retainer the ceiling fan.