An impeller includes a main plate, an annular side plate and blades. The blades each have: an inner circumferential end; an outer circumferential end; a sirocco blade portion formed as a forward-swept blade portion, and having an outlet angle that is greater than 90 degrees; and a turbo blade portion formed as a swept-back blade portion and including the inner circumferential end. The blades include a first blade portion and a second blade portion that are provided on respective sides of the main plate. The impeller including a region in which a first inter-blade distance is greater than a second inter-blade distance, where an inlet-blade distance is a distance between any adjacent two of the blades in the circumferential direction, the first inter-blade distance is the inter-blade distance of the first blade portion, and the second inter-blade distance is the inter-blade distance of the second blade portion.

A rotor blade includes an airfoil having an airfoil shape. The airfoil shape has a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in one of Table I, Table II, Table III, Table IV, Table V, Table VI, Table VII, Table VIII, or Table IX. The Cartesian coordinate values of X, Y and Z are non-dimensional values from 0% to 100% convertible to dimensional distances expressed in a unit of distance by multiplying the Cartesian coordinate values of X, Y and Z by a scaling factor of the airfoil in the unit of distance. The X and Y values, when connected by smooth continuing arcs, define airfoil profile sections at each Z value. The airfoil profile sections at Z values are joined smoothly with one another to form a complete airfoil shape.

A rotor blade includes an airfoil having an airfoil shape. The airfoil shape having a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in one of Table I, Table II, Table III, Table IV, Table V, Table VI, Table VII, Table VIII, or Table IX. The Cartesian coordinate values of X, Y and Z are non-dimensional values from 0% to 100% convertible to dimensional distances expressed in a unit of distance by multiplying the Cartesian coordinate values of X, Y and Z by a scaling factor of the airfoil in the unit of distance. The X and Y values, when connected by smooth continuing arcs, define airfoil profile sections at each Z value. The airfoil profile sections at Z values being joined smoothly with one another to form a complete airfoil shape.

A counter-rotating fan, comprising an impeller assembly and an air guide structure. The impeller assembly comprises a first stage impeller and a second stage impeller, of which the rotation directions are opposite. The pressure surfaces of first blades of the first stage impeller are configured to be opposite the suction surfaces of second blades of the second stage impeller, and from the blade root to the blade tip, each of the first blades and the second blades bends toward its own rotation direction. The air guide structure comprises a flow guide cover. The flow guide cover is provided at the center position of the air intake side of the first stage impeller, and the air intake side surface of the flow guide cover at least partially forms a flow guide surface, the flow guide surface extending along the axis of the first stage impeller in the direction away from the counter-rotating fan.

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.

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 rotor blade for a gas turbine engine is provided. The rotor blade includes a blade body formed of a first material; and a spar within a portion of the blade body, the spar formed of a second material that is different than the first material, the spar having an elongate body including a notch. The notch, weakened geometric feature, or other reduction in cross-section defines a frangible portion of the spar that is used to control a fracture of a rotor blade.

A rotor blade includes an airfoil having an airfoil shape. The airfoil shape has a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in Table I. The Cartesian coordinate values of X, Y and Z are non-dimensional values from 0% to 100% convertible to dimensional distances expressed in a unit of distance by multiplying the Cartesian coordinate values of X, Y and Z by a scaling factor of the airfoil in the unit of distance. The X and Y values, when connected by smooth continuing arcs, define airfoil profile sections at each Z value. The airfoil profile sections at Z values are joined smoothly with one another to form a complete airfoil shape.

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 airfoil profile for a turbine blade of a gas turbine is provided. The turbine blade may include an airfoil portion having an uncoated nominal profile substantially in accordance with Cartesian coordinate values of X, Y, and Z set forth in Table 1, wherein the X, Y, and Z coordinates are distances in inches measured in a Cartesian coordinate system, the corresponding X and Y coordinates, when connected by a smooth continuous arc, define one of a plurality of airfoil profile sections at each Z distance, and the plurality of airfoil profile sections, when joined together by smooth continuous arcs, define an airfoil shape.