摘要:
A cooled shroud assembly includes an angled slot and a plurality of dilution jet openings. The shroud forward cavity is modified such that at least one recirculation zone is produced. The angled slot forces an axial change in momentum of the hot gas flow and increases radial and axial pressure variation attenuation. The cooled shroud assembly isolates the shroud structure and seals from the hot flow path and a cooling flow from the dilution jet openings dilutes the hot gas flow. A series of recirculation zones shields the shroud carrier and high pressure seals from the hot gas flow.
摘要:
A method of modifying a turbine nozzle area comprises depositing a thermal barrier coating (TBC) on the nozzle endwalls to provide a minimum nozzle area, evaluating an airflow through the nozzle, and machining the TBC to increase the nozzle area. Adjacent segment area variation may be minimized, improving engine reliability by reducing the aerodynamic excitation to the down stream blade.
摘要:
A gas turbine engine is configured to use relatively cool, low pressure air discharged from a low pressure compressor to supply buffer air to lubrication sump seals. The engine is further configured such that the lubrication sump is thermally layered by isolating relatively hot, high pressure compressor air from the sump by utilizing a warm vent mixing cavity, which is located radially between of the hot high pressure compressor air and the cool buffer air, which is located in a buffer cavity between the vent cavity and the sump.
摘要:
Cooling air to the blades and disks of a gas turbine may be modulated to provide a variable turbine cooling flow. A bellows may be extended by providing a high pressure compressor discharge flow to an interior of the bellows. The bellows may be compressed when the interior of the bellows communicates with ambient pressure air. The extension/compression of the bellows moves an arm over orifices in a cooling air flow path. The pressure inside of the bellows is metered to move the arm over at least one orifice, thereby restricting cooling air flow when the engine is running at low power. The pressure inside of the bellows is metered to move the arm to uncover all of the slots to provide maximum cooling flow when the engine is running at high power. The resulting variable cooling flow system results in less need for cooling air at low powers, thus reducing engine fuel consumption.
摘要:
An air-cooled turbine blade is provided having an airfoil shape defined by a convex suction side wall, a concave pressure side wall, a leading edge, a trailing edge, a root and a tip, each wall including an interior surface that defines an interior with the edges, root and tip. The blade includes a plurality of independent cooling circuit flow paths within the blade interior and a roughened surface. The roughened surface is formed on an interior surface of at least one of the convex suction side wall and the concave pressure side wall, the roughened surface comprising a plurality of cylindrical depressions. Each depression includes a cylindrical wall coupled to a bottom wall by a chamfered edge formed therebetween, and the roughened surface defines at least a portion of one of the flow paths of the plurality of independent cooling circuit flow paths. Methods for forming the blade are also provided.
摘要:
An encapsulant is described for an optoelectronic device or optical component, which provides a coefficient of thermal expansion of less than 50 ppm/° C., with a variation of less than ±30%, and further provides an optical transmittance of at least 20% at a wavelength in the range of 400 to 900 nm, at an encapsulant thickness of about 1 mm. The encapsulant includes a filler consisting essentially of glass particles having diameters smaller than 500 μm, being essentially free of titania and lead oxide, and having a refractive index in the range of 1.48 to 1.60, with a variance of less than about 0.001. A method for making the encapsulant also is described, the method including steps of (1) processing the glass to form particles having diameters between 1 and 500 μm, (2) preparing an epoxy resin composition having at a cured stage a refractive index close to that of the glass filler particles, (3) mixing the epoxy resin composition with the filler particles to form a filled epoxy resin composition, (4) encapsulating an optoelectronic device with the filled epoxy resin composition, and (5) curing the filled epoxy resin composition.
摘要:
A new and distinct peppermint plant ‘Clackamas’ characterized by its resistance to Mint rust (Puccinia menthe Pers), Mint wilt (Ferticillium dahliae and Verticillium albo-atrum), and Spider mites as well as a more upright growth habit and a lighter green color the Black Mitcham peppermint plant.
摘要:
Compounds represented by formula I: or pharmaceutically acceptable salts and solvates thereof, wherein A, B, B′, X, Y, R1, R1′, R2, R2′, R3, R3′, R5, R5′, R6, m, n, or p are as defined herein, are useful for treating flaviviridae viral infections.
摘要:
A diffuser particle separator may be integrated into a gas turbine engine to remove corrosive dust and salt particles from the engine's core air flow. The air flow may pass over a series of particle accumulator entrance orifices, trapping particles in a particle accumulator while allowing the air flow to continue unimpeded. Since dust deposits may become molten at high temperatures, removal of dust from the core and secondary airflow may be critical for long-life superalloy and ceramic components, particularly those with small diameter air-cooling holes and thermal barrier coatings.