A wind turbine device may include four wings. A first wing may include a first leading edge and a first trailing edge, and a second wing may include a second leading edge a second trailing edge. The first and second leading edges may be positioned on opposite sides of the axis of rotation, the first and second trailing edges may be positioned on opposite sides of the axis of rotation, and the first and second leading edges may be positioned relatively further to the axis of rotation than the first and second trailing edges. A third wing may include a third leading edge and a third trailing edge, and a fourth wing may include a fourth leading edge and a fourth trailing edge. The third and fourth trailing edges may be each positioned proximate to the axis of rotation and positioned on opposite sides of the axis of rotation.

A runner for a hydraulic turbine configured to reduce fish mortality. The runner includes a hub and a plurality of blades extending from the hub. Each blade includes a root connected to the hub and a tip opposite the root. Each blade further includes a leading edge opposite a trailing edge, and a ratio of a thickness of the leading edge to a diameter of the runner can range from about 0.06 to about 0.35. Further, each blade has a leading edge that is curved relative to a radial axis of the runner.

A runner for a hydraulic turbine configured to reduce fish mortality. The runner includes a hub and a plurality of blades extending from the hub. Each blade includes a root connected to the hub and a tip opposite the root. Each blade further includes a leading edge opposite a trailing edge, and a ratio of a thickness of the leading edge to a diameter of the runner can range from about 0.06 to about 0.35. Further, each blade has a leading edge that is curved relative to a radial axis of the runner.

This invention relates to a leading edge device, a wind turbine blade, a method of manufacturing the leading edge device and a method of installing the leading edge device. The leading edge device comprises an erosion shield having an inner surface and an outer surface. The leading edge device further comprises a number of airflow modifying elements each having a local outer surface and a local inner surface. The airflow modifying elements has a 2D-profile or a 3D-profile extending in the circumference direction and/or in the longitudinal direction.

A rotor for a centrifugal compressor includes: a rotor main; an impeller; and a contact member. The rotor main body extends in an axis direction and includes a recessed part that is disposed on an outer circumferential surface. The impeller includes: a cylinder part having a cylindrical shape that extends around the axis direction and includes an inner circumferential surface with a fitting region tightly fitted to the outer circumferential surface of the rotor main body; an annular disc that extends from the cylinder part to a radial outer side with respect to the axis direction; a plurality of blades disposed at intervals in a circumferential direction on a surface facing one side in the axis direction of the annular disc; and a cover that covers the plurality of blades from the one side in the axis direction. The contact member is fitted into the recessed part.

A segmented blade, which includes a first blade segment having a first main beam, wherein the first main beam includes a first body portion disposed within the first blade segment and a first engaging portion extending from an end portion of the first body portion toward a direction which is away from the blade root; a second blade segment having a second main beam, wherein the second main beam includes a second body portion disposed within the second blade segment and a second engaging portion extending from an end portion of the second body portion toward a direction which approaches the blade root, and the second engaging portion being engaged in the first engaging portion; and an outer skin, which covers a gap between the first blade segment and the second blade segment. Also provided are a method for connecting segmented blades and a wind power generator set.

There is provided a wind turbine rotor blade having a blade outer side, a wall with a laminate, a blade inner side and at least a first and a second rotor blade part. The at least one first and second rotor blade parts are fixed together by means of at least one connecting unit in a separation plane. The connecting unit has at least one cable with a first end with cable fibers which are fixed in or at the laminate of the wall. The connecting unit has at least one projection at the first and second rotor blade parts respectively. The projections are respectively fixedly connected to the wall of rotor blade. The at least one cable is connected at at least one projection. The connecting unit has at least one tensioning element, by means of which the projections on the first and second rotor blade parts can be braced with each other.

The present invention relates to a modified airfoil, comprising: an original airfoil having an original leading edge profile with an original leading edge terminating at an x,y co-ordinate of 0,0 and a trailing edge terminating at an x,y co-ordinate of 1,0; and a shape modification element attached to the original airfoil such that a new leading edge of a new leading edge profile formed by the shape modification element terminates at a negative x co-ordinate relative to the original leading edge, wherein the new leading edge profile has a new leading edge profile shape with a NACA mean chord line between 0.3 and 0.7, a thickness between 12% and 17% of the chord line, with a maximum thickness located between 10% and 40% of the chord line, starting from the new leading edge of the new leading edge profile; and a leading edge radius between 1% and 6% of the chord line.

A centrifugal compressor impeller includes a plurality of blades on a front side that extend from a first axial side to an outer radial end of the impeller. The centrifugal impeller includes a back side having a nonlinear backwall. The backwall can include a flat area hear a bore of impeller, a flat area near a tip of the impeller, and a convex surface between the flat areas of the bore and the tip. In some forms the impeller further includes a concave surface between the convex surface and the tip to form an s-shape. A transition or inflection point can denote the change from convex to concave. The convex and/or concave surfaces can take any variety of forms such as constant radius sections and/or compound curves.

The present invention relates in general to the field of fluid reaction surfaces, and more specifically, to a fluid-foil impeller and method of use. One aspect of the fluid-foil impeller utilizes a plurality of fluid-foil discs that may be of uniform and/or variable thickness and configured to rotate rapidly in series to produce propulsion. Each fluid-foil disc comprises a leading edge, a trailing edge, a chord and a fixed pitch. The fluid-foil impeller may further include a standard or Venturi shroud that is designed to encompass the plurality of fluid-foil discs. The plurality of fluid-foil discs are configured to act in cooperation with the shroud to reduce losses incurred from turbulence and the conversion of mechanical work to fluid movement. Fluid may be acted upon by the plurality of fluid-foil discs and/or shroud, singly or in an array. A purpose of the invention is to provide a fluid-foil impeller and method of use that reduces harmful cavitation effects typically encountered by traditional propeller blades when operating at high revolutions per minute. An additional purpose of the invention is to provide a fluid-foil impeller that may be used efficiently and safely in a variety of industrial applications that requires successful propulsion a fluid.