Abstract:
A component includes at least one wall having an inner portion and an outer portion. A number of pins extend between the inner and outer portions. The pins define a mesh cooling arrangement with a number of flow channels. The inner portion of the wall defines a number of dimples. A method for forming a number of cooling holes in a component is described. The component has at least one wall with inner and outer portions. The inner portion defines a number of dimples. The method includes centering a drilling tool on a dimple, drilling at least one impingement cooling hole through the inner portion of the wall at the dimple using the drilling tool, and repeating the centering and drilling steps for a number of dimples to drill a number of impingement cooling holes in the inner portion of the wall.
Abstract:
A turbine wall includes a metal substrate having front and back surfaces. A thermal barrier coating is bonded atop the front surface. A network of flow channels is laminated between the substrate and the coating for carrying an air coolant therebetween for cooling the thermal barrier coating.
Abstract:
A pulse detonation system for a gas turbine engine having a longitudinal centerline axis extending therethrough includes a rotatable cylindrical member having a forward surface, an aft surface, and an outer circumferential surface, where a plurality of spaced detonation passages are disposed therethrough. Each detonation passage includes at least a portion having a longitudinal axis extending therethrough oriented at a circumferential angle to the longitudinal centerline axis. The pulse detonation system further includes a shaft rotatably connected to the cylindrical member and a stator configured in spaced arrangement with the forward surface of the cylindrical member and a portion of the shaft. The stator has at least one group of ports formed therein alignable with the detonation passages as the cylindrical member rotates. In this way, detonation cycles are performed in the detonation passages so that combustion gases exit the aft surface of the cylindrical member to create a torque which causes the cylindrical member to rotate. Each detonation passage further includes a first end located adjacent the forward surface of the cylindrical member and a second end located adjacent the aft surface of the cylindrical member.
Abstract:
A protected article includes a nickel-base superalloy substrate, an interlayer overlying the substrate, and a protective layer overlying the interlayer. The protective layer has a composition comprising at least one of rhodium, platinum, palladium, and ruthenium. In one composition, palladium is present in an amount of from about 1 to about 41 atomic percent; platinum is present in an amount of about (40+atomic percent palladium) atomic percent for palladium ranging from about 1 atomic percent to about 14 atomic percent and up to about 54 atomic percent for palladium ranging from about 15 atomic percent up to about 41 atomic percent; rhodium is present in an amount of at least about 24 atomic percent; zirconium, hafnium, titanium, and mixtures thereof are present in an amount of from zero up to about 5 atomic percent; and ruthenium is present in an amount of from zero up to about 5 atomic percent, balance impurities. The interlayer has a coefficient of thermal expansion intermediate between that of the substrate and that of the protective layer. The protected article is fabricated by furnishing the substrate, applying the interlayer over the substrate, and applying the protective layer over the interlayer. The application of the protective layer may be, for example, by welding or attachment of a solid piece.
Abstract:
A turbine blade includes a hollow airfoil integrally joined to a dovetail. The airfoil includes a perforate first bridge defining a flow channel behind the airfoil leading edge. A second bridge is spaced behind the first bridge and extends from a pressure sidewall of the airfoil short of the airfoil trailing edge. A third bridge has opposite ends joined to the pressure sidewall and the second bridge to define with the first bridge a supply channel for the leading edge channel, and defines with the second bridge a louver channel extending aft along the second bridge to its distal end at the pressure sidewall.
Abstract:
A gas turbine engine component includes a perforate metal wall having pores extending therethrough. The wall has a first surface covered by a thermal barrier coating. The pores have first ends which are covered by the thermal barrier coating, and the pores are ventilated from an opposite second surface of the wall for cooling the thermal barrier coating.
Abstract:
An electrode for rejuvenating a cooling passage within an airfoil, the electrode including a tip, an end, a conductive core extending between the tip and the end, and an insulating coating disposed on the conductive core. The insulating coating exposes a number of conductive strips of the conductive core extending between the tip and the end. The insulating coating forms a number of insulating portions and further exposes a number of spacer portions of the conductive core longitudinally positioned between the insulating portions. The insulating portions substantially span a distance between the tip and the end and are positioned between the conductive strips.
Abstract:
A turbine blade for a gas turbine engine, including an airfoil and integral dovetail for mounting the airfoil along a radial axis to a rotor disk inboard of a turbine shroud. The airfoil further includes: first and second sidewalls joined together at a leading edge and a trailing edge, where the first and second sidewalls extend from a root disposed adjacent the dovetail to a tip plate for channeling combustion gases thereover; and, at least one tip rib extending outwardly from the tip plate between the leading and trailing edges. The tip rib is oriented so that an axis extending longitudinally therethrough is at an angle with respect to the radial axis for at least a designated portion of an axial length of the turbine blade. Such angle may be substantially the same across the designated portion or may vary thereacross. Accordingly, a recirculation zone of the combustion gases is formed adjacent a distal end of the tip rib which reduces a leakage flow of the combustion gases between the airfoil and the shroud for at least the designated portion of an axial length of the turbine blade.
Abstract:
A turbine airfoil is provided having an integral tip cap and a pair of tip walls which extend radially outward past the tip cap to form a squealer tip. A coaxial pair of first and second holes extend through the tip cap and one of the tip walls respectively at an acute inclination angle, with the first hole being disposed so as to direct impingement cooling air on the tip wall having the second hole. A protective layer comprising a high temperature foil is disposed on the tip wall having the second hole therein.
Abstract:
A cooling system for cooling of the flow path surface region of an engine component used in a gas turbine engine and a method for making a system for cooling of the flow path surface region of an engine component used in a gas turbine engine. The method comprises the steps of channeling apertures in a substrate to a diameter of about 0.0005″ to about 0.02″ to allow passage of cooling fluid from a cooling fluid source; applying a bond coat of about 0.0005″ to about 0.005″ in thickness to the substrate such that the bond coat partially fills the channels; applying a porous inner TBC layer of at least about 0.01″ in thickness to the bond coat, such that the TBC fills the channels; applying an intermediate ceramic layer that is more dense than the inner TBC layer on top of the porous TBC; applying an outer TBC layer over the intermediate layer; and, passing cooling fluid from a cooling fluid source through the channel into the porous TBC. The density of thc outer TBC layer can be varied as needed to achieve desired cooling objectives. Because the channel exit is filled with porous TBC material, cooling fluid flows through the porous passageways into the inner TBC layer. Although the passageways provide a plurality of tortuous routes, the increased density of the TBC in the intermediate layer provides a resistance to flow of the cooling fluid and effectively causes the cooling fluid to more efficiently spread through the TBC in the inner layer before exiting at the outer surface.