Abstract: The subject matter described herein includes methods, systems, and computer readable media for controlling orientation of a photovoltaic collection system to track apparent movement of the sun. According to one aspect, a method for controlling orientation of a photovoltaic collection system to track apparent movement of the sun using a photovoltaic-collection-system-derived tracking algorithm is provided. The method includes determining an initial orientation of a photovoltaic collection system. The method further includes automatically deriving, using output from the photovoltaic collection system as it tracks apparent movement of the sun across the sky caused by spinning of the earth on its axis and its orbit around the sun, a tracking algorithm for controlling orientation of the photovoltaic collection system to track the apparent movement of the sun.

Abstract: Disclosed is a lightweight reflecting system for the concentration of solar radiation in which the reflecting optic is approximately sinusoidal in cross section and is maintained in this shape by minimal contact with a support frame. The reflector can be a flexible rectangular sheet deformed into a generally sinusoidal trough by compression between fixed or adjustable end supports. The sinusoid can be adjusted to be less than half a cycle by torsion applied to each end of the flexible sheet. A reflective film, polished metal, or similar material on the reflector surface can concentrate sunlight along a diffuse band rather than a sharp line, providing improved concentration levels for photovoltaic cells. The reflectors and their support frames can be mounted singly or severally on a tracking device that maximizes instantaneous power output by orienting the collectors toward the sun.

Abstract: The subject matter described herein includes methods, systems, and computer readable media for controlling orientation of a photovoltaic collection system to track apparent movement of the sun. According to one aspect, a method for controlling orientation of a photovoltaic collection system to track apparent movement of the sun using a photovoltaic-collection-system-derived tracking algorithm is provided. The method includes determining an initial orientation of a photovoltaic collection system. The method further includes automatically deriving, using output from the photovoltaic collection system as it tracks apparent movement of the sun across the sky caused by spinning of the earth on its axis and its orbit around the sun, a tracking algorithm for controlling orientation of the photovoltaic collection system to track the apparent movement of the sun.

Abstract: Disclosed are photovoltaic collection systems, friction drives, and method for tracking the sun and avoiding wind damage without the use of complicated or expensive mechanical systems. In particular, disclosed is friction drive system for coupling a support beam supporting a photovoltaic collection assembly to a support pillar. The frictional drive system can include a plurality of wheels positioned for rotatably and pivotably coupling the support beam to the support pillar such that the support beam will slip with respect to the support pillar under application of a wind torque of a predetermined amount. Further, at least one motor can apply torques to the wheels for moving the support beam with respect to the support pillar.

Abstract: Disclosed is a lightweight reflecting system for the concentration of solar radiation in which the reflecting optic is approximately sinusoidal in cross section and is maintained in this shape by minimal contact with a support frame. The reflector can be a flexible rectangular sheet deformed into a generally sinusoidal trough by compression between fixed or adjustable end supports. The sinusoid can be adjusted to be less than half a cycle by torsion applied to each end of the flexible sheet. A reflective film, polished metal, or similar material on the reflector surface can concentrate sunlight along a diffuse band rather than a sharp line, providing improved concentration levels for photovoltaic cells. The reflectors and their support frames can be mounted singly or severally on a tracking device that maximizes instantaneous power output by orienting the collectors toward the sun.

Abstract: The present invention provides a process for the lay-up of a composite laminate article, the article produced by this process, and the apparatus used to produce the composite laminate article. The composite laminate article may be, for example, an airfoil, particularly useful as a fan blade in a large high bypass ratio turbofan engine, wherein the blade is generally regarded as large and having a high degree of twist. In a preferred embodiment, the present invention provides a process for laying up a composite laminate article comprising a) reading a data set to enable the projection of an image of a ply section onto a work surface, the image indicating a ply section target point; b) laying up a ply section of composite laminating material within the image, wherein the ply section first contacts the work surface at the target point; and c) repeating steps (a)-(b) until the composite laminate article is complete.

Abstract: A jet aircraft fan case containment design that uses polyurethane to absorb fan blade fragments and uses polyurethane to prevent fan blade fragments from penetrating the fan case. The polyurethane is used in place of or to supplement KEVLAR® and/or fiberglass wraps used to contain fan blade fragments. The polyurethane is also used in place of aluminum alloy and stiffening ribs in the fan case.

Abstract: A jet aircraft fan case containment design that uses polyurethane to absorb fan blade fragments and uses polyurethane to prevent fan blade fragments from penetrating the fan case. The polyurethane is used in place of or to supplement KEVLAR® and/or fiberglass wraps used to contain fan blade fragments. The polyurethane is also used in place of aluminum alloy and stiffening ribs in the fan case.

Abstract: The present invention provides a process for the lay-up of a composite laminate article, the article produced by this process, and the apparatus used to produce the composite laminate article. The composite laminate article may be, for example, an airfoil, particularly useful as a fan blade in a large high bypass ratio turbofan engine, wherein the blade is generally regarded as large and having a high degree of twist. In a preferred embodiment, the present invention provides a process for laying up a composite laminate article comprising a) reading a data set to enable the projection of an image of a ply section onto a work surface, the image indicating a ply section target point; b) laying up a ply section of composite laminating material within the image, wherein the ply section first contacts the work surface at the target point; and c) repeating steps (a)-(b) until the composite laminate article is complete.

Abstract: A thin film that forms an interface between metal surfaces and polymeric inserts of aircraft engine fan blades. The thin film is formed from a chemical comprised of carbon black, at least one evaporable solvent, a combination of phenolic-like resins dissolved in the solvent and the balance filler and inert ingredients. The thin film, upon drying of the evaporable solvent, forms a phenolic that bonds with the metallic portion of the fan blade. After the polymeric material is applied to recesses in the fan blade and cured, a chemical bond is formed between the thin film and the elastomeric inserts. The bonded structure has improved FWT peak stresses and improved fracture toughness.

Abstract: A formulation used in the construction of lightweight aircraft engine fan blades. The formulation comprises a polyurethane elastomer composition, which is formed from a prepolymer, a curative and an antioxidant and molded into the blades. Optionally, a hindered amine light stabilizer and/or an ultraviolet absorber may be added to the formulation. The aircraft engine fan blade is formed from a metal, such as titanium alloy. Pockets are machined into the fan blade, so as to lessen the amount of metal used to construct the blade, thereby lowering the total weight of the blade. The formulation of the present invention is positioned in the pockets of the fan blade, so as to maintain the structural integrity of the blade against bird strikes and the like, while at the same time providing a fan blade which is significantly lighter than all-metal fan blades.

Abstract: A hybrid gas turbine engine airfoil is made by forming a metal airfoil with a pocket in one side thereof. The pocket is covered by a caul. An elastomeric fluid is injected into the pocket and cured therein for bonding thereto. The caul is removed from the airfoil to expose the cured elastomer conforming to the aerodynamic profile thereof.

Abstract: A method for compression molding a resin-impregnated preform to fabricate an impact-resistance, fiber-reinforced composite fan blade for use in a high bypass turbofan engine. The method is compatible with the use of high viscosity resin systems that contribute greater impact resistance to the fan blade, but whose flow through the fan blade during molding would cause unacceptable movement of the reinforcing fibers. The method entails restricting the flow of the resin system within the preform through selective placement of a resin-impervious material on certain surfaces of the preform, so as to prevent resin loss and fiber movement during the compression molding operation.

Abstract: The present invention provides a composite airfoil particularly useful as a fan blade, having a high degree of twist, in a large high bypass ratio turbofan engine. The composite airfoil of the present invention has a progression of filament reinforced airfoil laminations of varying span, arranged in order by span, and interrupted by at least one filament reinforced airfoil lamination having a span out of height order to form what is called a confused or broken shear plane where radially outer tips of the laminations end.