Abstract: A turbine shroud assembly asymmetrical cooling element such as a shroud segment or a baffle includes an arcuate panel. The panel has a plurality of cooling apertures extending through the panel and an axially extending midline of the panel parallel to an axis of rotation of the arcuate panel. A symmetric portion of the cooling apertures have a symmetrical density of aperture inlets that is symmetric with respect to the axially extending midline. An asymmetric portion of the cooling apertures have an asymmetrical density of aperture inlets that is asymmetric with respect to the axially extending midline. One exemplary cooling element includes a high density area of the cooling apertures in the asymmetric portion having a higher density of aperture inlets than in the symmetric portion. A low density area of the cooling apertures in the asymmetric portion has a lower density of aperture inlets than in the symmetric portion of the cooling apertures.

Abstract: A method is provided for repairing a surface portion of an article including a metallic environmental resistant coating on a substrate. The coating includes a coating outer portion bonded with the substrate through a diffusion zone that includes at least one feature, for example Al and/or an intermetallic phase, in an amount detrimental to application of a metallic replacement coating and/or repair of the article. The method comprises removing the coating outer portion to expose a surface of the diffusion zone. The substrate and the diffusion zone are heated at a temperature and for a time sufficient to diffuse and/or dissolve at least a portion of the at least one feature in the exposed surface and in a portion of the diffusion zone beneath the exposed surface to a level below the detrimental amount. This provides a replacement surface portion integral with diffusion zone. Then a metallic replacement coating outer portion is applied to the replacement surface portion.

Abstract: A gas turbine engine turbine blade includes a hollow airfoil extending radially from a blade root to a radially outer airfoil tip. The airfoil includes an airfoil outer wall having transversely spaced apart pressure and suction side walls meeting along chordally spaced apart leading and trailing edges of the airfoil. A radially extending cooling air supply channel within the airfoil includes a bank of pins integral with and extending transversely between the pressure and suction side walls. The bank of the pins is tuned such that a natural frequency of the blade associated with an engine forced driving mode of the blade is sufficiently away from a steady state engine operating frequency to substantially avoid natural frequency resonance of the blade during steady state engine operation. The bank of the pins is tuned by locations of the pins within the cooling air supply channel.

Abstract: A turbine nozzle bifurcated impingement baffle includes axially forward and aft chambers with a gap therebetween, impingement holes through forward and aft baffle walls of the forward and aft chambers respectively, and a plenum chamber in fluid flow communication with the forward and aft chambers. An exemplary embodiment of the bifurcated impingement baffle further includes a single cooling air inlet to the plenum chamber enclosed within a plenum chamber enclosure the plenum chamber. A sealing plate is mounted between and sealed to the plenum chamber enclosure and the forward and aft chambers. The sealing plate has forward and aft inlet apertures disposed between the plenum chamber and the forward and aft chambers respectively. Forward and aft end plates cap radially inner ends of the forward and aft chambers. An outlet aperture in the forward end plate has an interstage seal cavity feed tube disposed therethrough.

Abstract: A turbine nozzle segment includes a single hollow airfoil extending radially between radially outer and inner band segments. The airfoil has an airfoil wall with pressure and suction sides extending axially between leading and trailing edges of the airfoil. The airfoil wall surrounds a bifurcated cavity and a bifurcating rib extends through the bifurcated cavity and between the pressure and suction sides of the airfoil wall dividing the bifurcated cavity into forward and aft cavities. A stiffening rib extends radially outwardly from and along a radially outer surface of the outer band segment and axially and circumferentially from a pressure side forward corner of the outer band segment to the bifurcating rib. The outer and inner band segments, the bifurcating rib, and the stiffening rib are integral and made from a unitary one-piece casting.

Abstract: A turbine nozzle segment includes at least one hollow airfoil extending radially between radially outer and inner band segments, a clockwise open hook on a clockwise end at an aft end of the outer band segment, and counter-clockwise open hook on a counter-clockwise end at the aft end of the outer band segments. An exemplary embodiment of the turbine nozzle segment includes a load stop extending radially outwardly from the outer band segment. At least one aftwardly facing load face is at the aft end of the nozzle segment at the outer band segment. The clockwise open hook is C-shaped and the counter-clockwise open hook is a shiplap hook. Another embodiment of the turbine nozzle segment has only one hollow airfoil with an airfoil wall surrounding a bifurcated cavity divided into forward and aft cavities by a bifurcating rib extending between pressure and suction sides of the airfoil wall.

Abstract: A turbine nozzle segment includes a single hollow airfoil extending radially between radially outer and inner band segments. The airfoil has an airfoil wall with pressure and suction sides extending axially between leading and trailing edges of the airfoil. The airfoil wall surrounds a bifurcated cavity and a bifurcating rib extends through the bifurcated cavity and between the pressure and suction sides of the airfoil wall dividing the bifurcated cavity into forward and aft cavities. A stiffening rib extends radially outwardly from and along a radially outer surface of the outer band segment and axially and circumferentially from a pressure side forward corner of the outer band segment to the bifurcating rib. The outer and inner band segments, the bifurcating rib, and the stiffening rib are integral and made from a unitary one-piece casting.

Abstract: A turbine nozzle segment includes at least one hollow airfoil extending radially between radially outer and inner band segments, a clockwise open hook on a clockwise end at an aft end of the outer band segment, and counter-clockwise open hook on a counter-clockwise end at the aft end of the outer band segments. An exemplary embodiment of the turbine nozzle segment includes a load stop extending radially outwardly from the outer band segment. At least one aftwardly facing load face is at the aft end of the nozzle segment at the outer band segment. The clockwise open hook is C-shaped and the counter-clockwise open hook is a shiplap hook. Another embodiment of the turbine nozzle segment has only one hollow airfoil with an airfoil wall surrounding a bifurcated cavity divided into forward and aft cavities by a bifurcating rib extending between pressure and suction sides of the airfoil wall.

Abstract: A turbine nozzle bifurcated impingement baffle includes axially forward and aft chambers with a gap therebetween, impingement holes through forward and aft baffle walls of the forward and aft chambers respectively, and a plenum chamber in fluid flow communication with the forward and aft chambers. An exemplary embodiment of the bifurcated impingement baffle further includes a single cooling air inlet to the plenum chamber enclosed within a plenum chamber enclosure the plenum chamber. A sealing plate is mounted between and sealed to the plenum chamber enclosure and the forward and aft chambers. The sealing plate has forward and aft inlet apertures disposed between the plenum chamber and the forward and aft chambers respectively. Forward and aft end plates cap radially inner ends of the forward and aft chambers. An outlet aperture in the forward end plate has an interstage seal cavity feed tube disposed therethrough.

Abstract: A method for assembling a turbine nozzle for a gas turbine engine facilitates improving cooling efficiency of the turbine nozzle. The method includes providing a hollow doublet including a leading airfoil and a trailing airfoil coupled by at least one platform, wherein each airfoil includes a first sidewall and a second sidewall that extend between a respective leading and trailing edge. The method also includes inserting an insert into at least one of the airfoils, wherein the insert includes a first sidewall including a first plurality of cooling openings that extending therethrough, and a second sidewall including a second plurality of cooling openings extending therethrough, and wherein the first plurality of cooling openings facilitate more cooling of the airfoil than the second plurality of cooling openings.

Abstract: A method for assembling a turbine nozzle for a gas turbine engine facilitates improving cooling efficiency of the turbine nozzle. The method includes providing a hollow doublet including a leading airfoil and a trailing airfoil coupled by at least one platform, wherein each airfoil includes a first sidewall and a second sidewall that extend between a respective leading and trailing edge. The method also includes inserting an insert into at least one of the airfoils, wherein the insert includes a first sidewall including a first plurality of cooling openings that extending therethrough, and a second sidewall including a second plurality of cooling openings extending therethrough, and wherein the first plurality of cooling openings facilitate more airfoil vane sidewall cooling than the second plurality of cooling openings.

Abstract: A method is provided for repairing a surface portion of an article including a metallic environmental resistant coating on a substrate. The coating includes a coating outer portion bonded with the substrate through a diffusion zone that includes at least one feature, for example Al and/or an intermetallic phase, in an amount detrimental to application of a metallic replacement coating and/or repair of the article. The method comprises removing the coating outer portion to expose a surface of the diffusion zone. The substrate and the diffusion zone are heated at a temperature and for a time sufficient to diffuse and/or dissolve at least a portion of the at least one feature in the exposed surface and in a portion of the diffusion zone beneath the exposed surface to a level below the detrimental amount. This provides a replacement surface portion integral with diffusion zone. Then a metallic replacement coating outer portion is applied to the replacement surface portion.

Abstract: A method for assembling a turbine nozzle for a gas turbine engine facilitates improving cooling efficiency of the turbine nozzle. The method includes providing a hollow doublet including a leading airfoil and a trailing airfoil coupled by at least one platform, wherein each airfoil includes a first sidewall and a second sidewall that extend between a respective leading and trailing edge. The method also includes inserting an insert into at least one of the airfoils, wherein the insert includes a first sidewall including a first plurality of cooling openings that extending therethrough, and a second sidewall including a second plurality of cooling openings extending therethrough, and wherein the first plurality of cooling openings facilitate more cooling of the airfoil than the second plurality of cooling openings.

Abstract: A method for assembling a turbine nozzle for a gas turbine engine facilitates improving cooling efficiency of the turbine nozzle. The method includes providing a hollow doublet including a leading airfoil and a trailing airfoil coupled by at least one platform, wherein each airfoil includes a first sidewall and a second sidewall that extend between a respective leading and trailing edge. The method also includes inserting an insert into at least one of the airfoils, wherein the insert includes a first sidewall including a first plurality of cooling openings that extending therethrough, and a second sidewall including a second plurality of cooling openings extending therethrough, and wherein the first plurality of cooling openings facilitate more airfoil vane sidewall cooling than the second plurality of cooling openings.

Abstract: A gas turbine engine includes rotor blades including airfoils that facilitates reducing manufacturing losses due to airfoil trailing edge scarfing. Each airfoil includes a first and second sidewall connected at a leading edge and a trailing edge. The sidewalls define a cooling cavity that includes at least a leading edge chamber bounded by the sidewalls and the airfoil leading edge, and a trailing edge chamber bounded by sidewalls and the airfoil trailing edge. The cooling cavity trailing edge chamber includes a tip region, a throat, and a passageway region connected in flow communication such that the throat is between the tip region and the passageway region. Furthermore, the tip region is bounded by the airfoil tip and extends divergently from the throat, such that a width of the tip region is greater than a width of the throat.

Abstract: A method is provided for repairing a surface portion of an article including a metallic environmental resistant coating on a substrate. The coating includes a coating outer portion bonded with the substrate through a diffusion zone that includes at least one feature, for example Al and/or an intermetallic phase, in an amount detrimental to application of a metallic replacement coating and/or repair of the article. The method comprises removing the coating outer portion to expose a surface of the diffusion zone. The substrate and the diffusion zone are heated at a temperature and for a time sufficient to diffuse and/or dissolve at least a portion of the at least one feature in the exposed surface and in a portion of the diffusion zone beneath the exposed surface to a level below the detrimental amount. This provides a replacement surface portion integral with diffusion zone. Then a metallic replacement coating outer portion is applied to the replacement surface portion.

Abstract: A gas turbine engine includes rotor blades including airfoils that facilitates reducing manufacturing losses due to airfoil trailing edge scarfing. Each airfoil includes a first and second sidewall connected at a leading edge and a trailing edge. The sidewalls define a cooling cavity that includes at least a leading edge chamber bounded by the sidewalls and the airfoil leading edge, and a trailing edge chamber bounded by sidewalls and the airfoil trailing edge. The cooling cavity trailing edge chamber includes a tip region, a throat, and a passageway region connected in flow communication such that the throat is between the tip region and the passageway region. Furthermore, the tip region is bounded by the airfoil tip and extends divergently from the throat, such that a width of the tip region is greater than a width of the throat.

Abstract: A method for assembling a turbine nozzle for a gas turbine engine facilitates improving cooling efficiency of the turbine nozzle. The method includes providing a hollow doublet including a leading airfoil and a trailing airfoil coupled by at least one platform, wherein each airfoil includes a first sidewall and a second sidewall that extend between a respective leading and trailing edge. The method also includes inserting an insert into at least one of the airfoils, wherein the insert includes a first sidewall including a first plurality of cooling openings that extending therethrough, and a second sidewall including a second plurality of cooling openings extending therethrough, and wherein the first plurality of cooling openings facilitate more cooling of the airfoil than the second plurality of cooling openings.