Abstract: A cooled shroud assembly for a gas turbine engine having a longitudinal centerline includes at least one arcuate shroud segment surrounding a row of rotating turbine blades. The shroud segment has a forward flange, an aft flange defining an axially-facing aft edge, and an inwardly-facing flowpath surface, and the shroud segment lacks cooling holes for cooling the aft flange or the aft edge. At least one stationary turbine nozzle is disposed axially next to the shroud segment and includes an airfoil-shaped airfoil and an arcuate outer band disposed at a radially outer end of the airfoil and positioned axially adjacent to the shroud. At least one cooling hole is formed in the outer band in fluid communication with a source of cooling air. The cooling hole is positioned so as to direct a flow of cooling air against the shroud segment.

Abstract: A shroud assembly is provided for a gas turbine engine having a temperature at a hot operating condition substantially greater than at a cold assembly condition thereof. The shroud assembly includes at least one arcuate shroud segment adapted to surround a row of rotating turbine blades. The shroud segment has an arcuate, axially extending mounting flange. A shroud hanger includes an arcuate, axially-extending hook. A dimension of one of the shroud segments and the shroud hanger are selected to produce a preselected dimensional relationship therebetween at the hot operating condition.

Abstract: A shroud segment is adapted to surround a row of rotating turbine blades in a gas turbine engine. The shroud segment includes: an arcuate, axially extending first mounting flange having a first radius of curvature, and an arcuate, axially extending first overhang having a second radius of curvature. The overhang is disposed parallel to and radially inboard of the first mounting flange so that a first groove is defined between the first mounting flange and the first overhang. The first and second radii of curvature are substantially different from each other. The shroud segment may attached to a supporting structure or shroud hanger to form a shroud assembly.

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 shroud assembly is provided for a gas turbine engine that has a temperature at a hot operating condition substantially greater than at a cold assembly condition thereof. The shroud assembly includes: at least one arcuate shroud segment adapted to surround a row of rotating turbine blades which has an arcuate, axially extending mounting flange; a shroud hanger having an arcuate, axially-extending hook disposed in mating relationship to the mounting flange; and an arcuate C-clip having inner and outer arms overlapping the hook and the mounting flange. The curvatures of the mounting flange and the inner arm of the C-clip are selected so as to define a matched interface therebetween. Their curvatures are substantially greater that the curvature of the hook.

Abstract: A cooled turbine shroud includes an arcuate flow path surface adapted to surround a row of rotating turbine blades, and an opposed interior surface; a forward overhang defining an axially-facing leading edge, an outwardly-extending forward wall and an outwardly-extending aft wall; opposed first and second sidewalls, wherein the forward and aft walls and the sidewalls define an open shroud plenum; at least one leading edge cooling hole extending from the shroud plenum to the leading edge; and at least one sidewall cooling hole extending from the plenum to one of the sidewalls. The flow path surface is free of cooling holes and may include a protective coating applied thereto.

Abstract: A compliant seal assembly for a rotating machine is provided. The seal assembly includes a static member, a movable member and a biasing member. The static member is rigidly fixed to the machine at its fore and aft ends. The movable portion has a first sealing surface configured to seal against a rotating member and a rear surface, which may be exposed to a fluid pressure to urge the first sealing surface toward a sealing position with the rotating member. The static and the movable members further include sealing surfaces at their fore, aft and end faces to seal against leakage of gas between the static and the movable members. The biasing member is configured to support the movable member on the static member and to urge the movable member away from the sealing position so as to reduce force on the rotating member during contact of the rotating member with the first sealing surface of the movable member.

Abstract: An article, for example a turbine engine component such as a shroud, airfoil, etc., comprises a wall having a first wall surface subject to a first temperature, for example from the flow stream of the engine. The wall includes a second wall surface, substantially opposite the first wall surface, for exposure to a cooling fluid, for example cooling air. The second wall surface includes a plurality of adjacent ribs protruding from the second wall surface to facilitate transfer of heat from the second wall surface. The ribs comprise a plurality of elongated rib portions each spaced apart one from another across a gap between rib portions, the gaps having a gap length in the range of about 0.002-0.05″.

Abstract: An article, for example a turbine engine component such as a shroud, airfoil, etc., comprises a wall having a first wall surface subject to a first temperature, for example from the flow stream of the engine. The wall includes a second wall surface, substantially opposite the first wall surface, for exposure to a cooling fluid, for example cooling air. The second wall surface includes a plurality of adjacent ribs protruding from the second wall surface to facilitate transfer of heat from the second wall surface. The ribs comprise a plurality of elongated rib portions each spaced apart one from another across a gap between rib portions, the gaps having a gap length in the range of about 0.002-0.05″.

Abstract: A method for repairing a turbine nozzle segment having at least one vane disposed between outer and inner bands includes separating the inner band from the nozzle segment, and joining the inner band to a newly manufactured replacement casting having an outer band and at least one vane. The replacement casting includes a mounting platform formed on one end of the vane and a boss formed on the mounting platform. A collar is joined to the inner band and has a slot formed therein. The boss is then inserted into the slot, and the mounting platform is received in a recess formed in the inner band. Joining is completed by joining the boss to the collar and the mounting platform to the inner band.