Claims
- 1. A shroud panel for a turbine shroud positionable radially above a plurality of turbine rotor blades comprising:
- a panel forward hook extending axially for mounting said panel to a complementary forward slot of a component of said turbine shroud;
- a panel aft hook spaced axially from said panel forward hook and extending axially for mounting said panel to a complementary aft hook of said turbine shroud;
- said panel forward hook having oppositely facing radially outer and inner lands, said outer land being defined by a plurality of pads circumferentially spaced apart from each other by a respective recess, with said pads and recess being disposed coextensively over said inner land; and
- said panel, including said panel forward hook, being arcuate in a circumferential direction, with said panel forward hook being sized to engage said forward slot substantially concentrically therein.
- 2. A panel according to claim 1 wherein said pads have a radial height predeterminedly sized relative to a radial height of said forward slot to minimize radial clearance therebetween for minimizing leakage therethrough of compressor bleed sir while allowing assembly of said panel forward hook into said slot without interference.
- 3. A panel according to claim 2 wherein said pads comprise first and second pads disposed at circumferentially opposite ends of said panel to first contact said forward slot upon thermal expansion of said panel for minimizing radial travel of said panel forward hook in said forward slot.
- 4. A panel according to claim 3 further comprising a third pad spaced circumferentially between said first and second pads, with a first recess being disposed between said first and third pads and a second recess being disposed between said second and third pads.
- 5. A panel according to claim 3 in combination with an annular outer casing and a hanger fixedly joined to said outer casing to define said turbine shroud and wherein:
- said hanger includes said forward slot supporting said panel forward hook, and also includes said turbine shroud aft hook defining a hanger aft hook supporting said panel aft hook, and said hanger further includes a plurality of axial inlet apertures extending therethrough radially above said hanger forward slot for channeling said bleed air;
- said panel includes a plurality of outlet apertures therethrough, and is spaced radially inwardly from said hanger to define a shroud cavity therebetween supplied by said bleed air from said inlet apertures to effect a pressure backflow margin across said outlet apertures; and
- said panel forward hook is sized to minimize radial clearance with said cooperating hanger forward slot for minimizing leakage of said bleed air therethrough from said shroud cavity to in turn maintain said backflow margin.
- 6. A turbine shroud positionable radially above a plurality of turbine rotor blades comprising:
- an annular outer casing;
- a hanger fixedly joined to said outer casing and including a hanger forward slot and a hanger aft hook;
- a shroud panel including:
- a panel forward hook extending axially to engage said hanger forward slot;
- a panel aft hook spaced axially from said panel forward hook and extending axially to engage said hanger aft hook;
- said panel forward hook having radially outer and inner lands, said outer land being defined by a plurality of pads circumferentially spaced apart from each other by a respective recess; and
- said panel, including said panel forward hook, being arcuate in a circumferential direction, with said panel forward hook being sized to engage said hanger forward slot substantially concentrically therein; and
- wherein said pads have a radial height predeterminedly sized relative to a radial height of said hanger forward slot to minimize radial clearance therebetween for minimizing leakage therethrough of compressor bleed air while allowing assembly of said panel forward hook into said hanger forward slot without interference.
- 7. A turbine shroud according to claim 6 wherein said pads comprise first and second pads disposed at circumferentially opposite ends of said panel to first contact said hanger forward slot upon thermal expansion of said panel for minimizing radial travel of said panel forward hook in said hanger forward slot.
- 8. A turbine shroud according to claim 7 further comprising a third pad spaced circumferentially between said first and second pads, with a first recess being disposed between said first and third pads and a second recess being disposed between said second and third pads.
- 9. A turbine shroud according to claim 7 wherein:
- said hanger further includes a plurality of axial inlet apertures extending therethrough radially above said hanger forward slot for channeling said bleed air;
- said panel includes a plurality of outlet apertures therethrough, and is spaced radially inwardly from said hanger to define a shroud cavity therebetween supplied by said bleed air from said inlet apertures to effect a pressure backflow margin across said outlet apertures; and
- said panel forward hook is sized to minimize radial clearance with said cooperating hanger forward slot for minimizing leakage of said bleed air therethrough from said shroud cavity to in turn maintain said backflow margin.
- 10. A turbine shroud according to claim 9 wherein:
- said hanger forward slot is defined by a hanger forward hook extending axially aft and includes a radially outer land spaced from a radially inner land comprising the outer surface of said hanger forward hook, said outer and inner lands of said hanger forward slot being uniform; and
- said inner land of said panel forward hook is uniform and includes a center region;
- said first and second pads contact said outer land of said hanger forward slot upon said thermal expansion to define an outer flow restriction channel therebetween, and said center region of said panel forward hook correspondingly contacts said inner land of said hanger forward slot to define a pair of inner flow restriction channels therebetween.
- 11. A turbine shroud according to claim 10 wherein said panel forward hook is sized so that said outer and inner flow restriction channels have predetermined flow areas for metering leakage flow of said bleed air therethrough from said shroud cavity to control said backflow margin therein.
- 12. A turbine shroud according to claim 11 wherein said panel forward hook is sized so that said flow area of said outer flow restriction channel is substantially equal to a collective flow area of said inner flow restriction channels.
CROSS REFERENCE TO RELATED APPLICATION
The present invention is related to concurrently filed patent application Ser. No. 08/467,437, filed Jun. 6, 1995, and entitled "SEALABLE TURBINE SHROUD HANGER".
US Referenced Citations (11)
Non-Patent Literature Citations (1)
Entry |
General Electric Company, CF34-3A1 gas turbine engine in production more than 1 year; 3 figures showing high pressure turbine shrouds and unpublished proposed temporary fix. |