Abstract:
A method for assembling a gas turbine engine is provided. The method comprises coupling a first turbine nozzle within the engine, coupling a second turbine nozzle circumferentially adjacent the first turbine nozzle such that a gap is defined between the first and second turbine nozzles and providing at least one spline seal including a substantially planar body. The method also comprises forming at least one retainer tab to extend outward from the body portion of the at least one spline seal, and inserting the at least one spline seal into a slot defined in at least one of the first and second turbine nozzles to facilitate reducing leakage through said gap, such that the at least one retainer tab facilitates retaining the retainer tab within the turbine nozzle slot.
Abstract:
An airfoil for a gas turbine engine includes a root, a tip, a leading edge, a trailing edge, and opposed pressure and suction sidewalls extending generally along a radial axis. The airfoil includes a tip cap extending between the pressure and suction sidewalls; and spaced-apart suction-side and pressure-side tip walls extending radially outward from the tip cap to define a tip cavity therebetween. The pressure-side tip wall includes a continuously concave curved arcuate portion, at least a section of which extends circumferentially outward from a radial axis of the airfoil. At least a portion of the pressure-side tip wall is recessed from the pressure sidewall to define an outwardly facing tip shelf, such that the pressure-side tip wall and the tip shelf define a trough therebetween.
Abstract:
A C-clip for a gas turbine engine includes an arcuate outer arm having a first radius of curvature; an arcuate, inner arm having a second radius of curvature which is substantially greater than the first radius of curvature; and an arcuate extending flange connecting the outer and inner arms. The flange, the outer arm, and the inner arm collectively define a generally C-shaped cross-section. A shroud assembly includes a shroud segment with a mounting flange, and a shroud hanger with an arcuate hook disposed in mating relationship to the mounting flange. An arcuate C-clip having inner and outer arms overlaps the hook and the mounting flange. The shroud segment and the C-clip are subject to thermal expansion at the hot operating condition. A dimension of one of the shroud segment and the C-clip are selected to produce a preselected dimensional relationship therebetween at the hot operating condition.
Abstract:
A turbine blade includes an airfoil having pressure and suction sidewalls extending between leading and trailing edges and root and tip. The tip includes squealer ribs extending from a tip floor forming an open tip cavity. The rib along the pressure sidewall has a squared external corner, and a flute extends along the base of the rib at the tip floor.
Abstract:
According to an embodiment of the invention, a method for repairing a coated high pressure turbine blade, which has been exposed to engine operation, to restore coated airfoil contour dimensions of the blade, and improve upon the prior bond coat is disclosed. The method comprises providing an engine run high pressure turbine blade including a base metal substrate made of a nickel-based alloy and having thereon a thermal barrier coating system. The thermal barrier coating system comprises a diffusion bond coat on the base metal substrate and a top ceramic thermal barrier coating comprising a yttria stabilized zirconia material. The top ceramic thermal barrier coating has a nominal thickness t. The method further comprises removing the thermal barrier coating system, wherein a portion of the base metal substrate also is removed, and determining the thickness of the base metal substrate removed. The portion of the base metal substrate removed has a thickness, Δt. The method also comprises applying a β phase NiAl overlay coating to the substrate, and determining the difference in thickness, Δx, between the β phase NiAl overlay coating and the previously removed bond coat. The method further comprises reapplying the top ceramic thermal barrier coating to a nominal thickness of t+Δt−Δx, wherein Δt compensates for the portion of removed base metal substrate. Advantageously, the coated airfoil contour dimensions of the high pressure turbine blade are restored to about the coated dimensions preceding the engine run.
Abstract:
A turbine stage includes a row of airfoils joined to corresponding platforms to define flow passages therebetween. Each airfoil includes opposite pressure and suction sides and extends in chord between opposite leading and trailing edges. Each platform has a scalloped flow surface including a bulge adjoining the pressure side adjacent the leading edge, and a bowl adjoining the suction side aft of the leading edge.
Abstract:
A gas turbine engine having a longitudinal centerline axis therethrough, including: a fan section at a forward end of the gas turbine engine including at least a first fan blade row connected to a first drive shaft; a booster compressor positioned downstream of and in at least partial flow communication with the fan section including a plurality of stages, each stage including a stationary compressor blade row and a rotating compressor blade row connected to a drive shaft and interdigitated with the stationary compressor blade row; a core system positioned downstream of the compressor, where the core system further includes an intermediate compressor positioned downstream of and in flow communication with the booster compressor, the intermediate compressor being connected to a second drive shaft, and a combustion system for producing pulses of gas having increased pressure and temperature from a fluid flow provided to an inlet thereof so as to produce a working fluid at an outlet; and, a low pressure turbine positioned downstream of and in flow communication with the core system, the low pressure turbine being utilized to power the first drive shaft. The core system may also include an intermediate turbine positioned downstream of the combustion system in flow communication with the working fluid, where the intermediate turbine is utilized to power the second drive shaft. A first source of compressed air having a predetermined pressure is provided to the combustion system inlet and a second source of compressed air having a pressure greater than the first source of compressed air is provided to cool the combustion system.
Abstract:
A turbine blade includes an airfoil having pressure and suction sidewalls extending between leading and trailing edges and root and tip. The tip includes squealer ribs extending from a tip floor forming an open tip cavity. The rib along the pressure sidewall has a squared external corner, and a flute extends along the base of the rib at the tip floor.
Abstract:
According to an embodiment of the invention, a method for repairing a coated high pressure turbine blade, which has been exposed to engine operation, to restore coated airfoil contour dimensions of the blade, and improve upon the prior bond coat is disclosed. The method comprises providing an engine run high pressure turbine blade including a base metal substrate made of a nickel-based alloy and having thereon a thermal barrier coating system. The thermal barrier coating system comprises a diffusion bond coat on the base metal substrate and a top ceramic thermal barrier coating comprising a yttria stabilized zirconia material. The top ceramic thermal barrier coating has a nominal thickness t. The method further comprises removing the thermal barrier coating system, wherein a portion of the base metal substrate also is removed, and determining the thickness of the base metal substrate removed. The portion of the base metal substrate removed has a thickness, Δt. The method also comprises applying a β phase NiAl overlay coating to the substrate, and determining the difference in thickness, Δx, between the β phase NiAl overlay coating and the previously removed bond coat. The method further comprises reapplying the top ceramic thermal barrier coating to a nominal thickness of t+Δt-Δx, wherein Δt compensates for the portion of removed base metal substrate. Advantageously, the coated airfoil contour dimensions of the high pressure turbine blade are restored to about the coated dimensions preceding the engine run.
Abstract:
A method facilitates assembling a turbine engine to facilitate preventing ice accumulation on the turbine engine during engine operation. The method comprises coupling at least one heat pipe to the engine such that a first end of the at least one heat pipe is coupled in thermal communication with a heat source, and coupling a second end of the at least one heat pipe in thermal communication with an outer surface of an engine component that is upstream from the heat source.