Low-ductility open channel turbine shroud
A turbine shroud apparatus for a gas turbine engine includes: a plurality of arcuate shroud segments arranged as an annular shroud, each of the shroud segments comprising low-ductility material and having a cross-sectional shape defined by opposed forward and aft walls, and opposed inner and outer walls, the walls extending between opposed first and second end faces, wherein an open channel is formed through the outer wall of each shroud segment; an annular stationary structure surrounding the shroud segments; and a hanger received in the open channel of each shroud segment and mechanically coupled to the stationary structure, each of the hangers passing through the respective open channel and including an enlarged portion having greater cross-sectional area than the open channel, the enlarged portion engaging the outer wall of the respective shroud segment, so as to retain the shroud segment radially relative to the stationary structure.
1. A turbine shroud apparatus for a gas turbine engine, comprising:
a plurality of arcuate shroud segments arranged to form an annular shroud, each of the shroud segments comprising low-ductility material and having a cross-sectional shape defined by opposed forward and aft walls, and opposed inner and outer walls, the walls extending between opposed first and second end faces, wherein an open channel is formed through the outer wall of each shroud segment, wherein the open channel is shorter than the shroud segment in a circumferential direction, and the shroud segment includes offset stub walls extending radially inward from each of the forward and aft walls;
an annular stationary structure surrounding the shroud segments; and
a hanger received in the open channel of each shroud segment, each of the hangers passing through the respective open channel and having a T-shaped cross section comprising a central portion extending through the open channel and contacting the annular stationary structure, the central portion being flanked by at least one laterally-extending rail which engages the outer wall of the respective shroud segment, so as to retain the shroud segment in a radial direction relative to the stationary structure, wherein the central portion of each hanger is mechanically coupled to the stationary structure by a mechanical fastener.
2. The apparatus of claim 1 wherein the stationary structure includes substantially rigid annular forward and aft bearing surfaces which bear against the forward and aft walls, respectively, of each shroud segment, so as to restrain the shroud segments from axial movement and radially inward movement relative to the stationary structure.
3. The apparatus of claim 1 wherein the stationary structure comprises:
an annular turbine stator;
an annular aft spacer including a flange extending radially inward at its aft end which defines an axially-facing aft bearing surface; and
a forward spacer including a hook protruding radially inward which defines an axially-facing forward bearing surface.
4. The apparatus of claim 1 wherein the hanger includes:
an elongated body sized to fit through the open channel; and
a boss protruding radially outward from the body, the boss having a height from the body approximately equal to a thickness of the outer wall.
5. The apparatus of claim 1 wherein each of the shroud segments comprises a ceramic matrix composite material.