Abstract: A blade for a wind turbine has a hollow or exoskeleton blade body. The blade body has a leading edge and a trailing edge along a span thereof. The blade body includes a first blade portion and a second blade portion wherein the first blade portion and the second blade portion are integrated with one another along at least 90% of the leading edge, and are in uncoupled contact at the trailing edge. The uncoupled contact permits the first blade portion and second blade portion to experience relative movement at the trailing edge when the blade body twists.

Abstract: A blade for a wind turbine has a hollow or exoskeleton blade body. The blade body has a leading edge and a trailing edge along a span thereof. The blade body includes a first blade portion and a second blade portion wherein the first blade portion and the second blade portion are integrated with one another along at least 90% of the leading edge, and are in uncoupled contact at the trailing edge. The uncoupled contact permits the first blade portion and second blade portion to experience relative movement at the trailing edge when the blade body twists.

Abstract: A rotor blade system includes a hub for rotational movement in a defined direction of rotation. A first airfoil having a quarter-chord defined along a span thereof is coupled to the hub, but is uncoupled from the rotational movement of the hub. A second airfoil having a quarter-chord defined along a span thereof is coupled to the hub for rotation in direct correspondence with the rotational movement of the hub. The quarter-chord of the first airfoil leads the quarter-chord of the second airfoil when the hub experiences its rotational movement in the defined direction of rotation. A connector couples the tip of the first airfoil to the tip of the second airfoil.

Abstract: A rotor blade system includes a hub for rotational movement in a defined direction of rotation. A first airfoil having a quarter-chord defined along a span thereof is coupled to the hub, but is uncoupled from the rotational movement of the hub. A second airfoil having a quarter-chord defined along a span thereof is coupled to the hub for rotation in direct correspondence with the rotational movement of the hub. The quarter-chord of the first airfoil leads the quarter-chord of the second airfoil when the hub experiences its rotational movement in the defined direction of rotation. A connector couples the tip of the first airfoil to the tip of the second airfoil.

Abstract: A lightweight, high strength, water ski hydrofoil assembly includes a diamond planform hydrofoil wing and a V-strut connecting the wing to a parallel ski support platform. The diamond planform wing is formed as a unit and the separately formed V-strut and platform secured thereto. The wing is provided with a foam plastic, aluminum or composite core element, while the V-strut and platform are provided with core elements selected from aluminum or aluminum alloys, composites and balsa wood. In the preferred embodiment, the core elements are provided with an intermediate layer of molded composite material (resin impregnated fiberglass and graphite fibers, or cloth) and an outer layer of rubber. The rubber coating may be applied to the core elements by injection molding, and confined to the leading and trailing edges of the components, with the intermediate layer being omitted, in some embodiments.