Fluid cooled porous stator structure

Claim 2

In a gas turbine engine including a compressor, a combustor and a turbine, fluid cooled turbine apparatus comprising: a row of circumferentially spaced-apart turbine buckets mounted for rotation about an axis, said turbine buckets extending radially of said axis across an annular passageway for the flow of high temperature motive fluid during engine operation, an annular porous shroud circumferentially surrounding the outer tips of said turbine buckets in closely spaced relation thereto so as to control leakage of high temperature motive fluid around the tips during engine operation, means for supplying cooling fluid to at least a portion of the outer surface of said shroud during engine operation at a pressure higher than the static pressure exerted on the inner surface of said shroud by high temperature motive fluid in the annular passageway, means defining a plenum radially outward of said shroud, annular support means radially interposed between said annular shroud and said plenum for supporting said annular shroud, said support means engaging said shroud and having passages therein such that only a portion of the outer surface of said shroud is in fluid communication with means defining said plenum, an annular member circumferentially surrounding said annular shroud and having a plurality of axially spaced circumferential ridges projecting radially inward into contact with said shroud such that at least two substantially closed axially spaced annular regions are formed between said annular member and said shroud, said annular member having passages therein providing fluid communication between the means defining a plenum and said annular regions for supplying cooling air to said annular regions, said passages being sized to maintain a substantially uniform pressure drop across said shroud during engine operation whereby said shroud is cooled in a substantially uniform manner.

Claim 3

Air cooled turbine apparatus as defined by claim 1 further comprising a layer of abradable material on the inner surface of said shroud, said abradable material having relatively large passages therein for permitting substantially unrestricted flow of cooling air therethrough even subsequent to rubbing between the tips of said turbine buckets and said shroud.

Claim 4

In a gas turbine engine including a compressor, a combustor, and a turbine, fluid cooled turbine apparatus comprising: a row of circumferentially spaCed-apart turbine buckets mounted for rotation about an axis, said turbine buckets extending radially of said axis across an annular passageway for the flow of high temperature motive fluid during engine operation, an annular porous shroud circumferentially surrounding the outer tips of said turbine buckets in closely spaced relationship thereto so as to control leakage of high temperature motive fluid around the tips during engine operation, means for supplying cooling fluid to at least a portion of the outer surface of said shroud during engine operation at a pressure higher than the static pressure exerted on the inner surface of said shroud by high temperature motive fluid in the annular passageway, annular support means radially interposed between said annular shroud and a plenum, located radially outward of said shroud, for supporting said annular shroud, said support means engaging said shroud and having passages therein such that only a portion of the outer surface of said shroud is in fluid communication with said plenum, an annular member circumferentially surrounding said annular shroud and having a first plurality of axially spaced circumferential ridges and a second plurality of circumferentially spaced axial ridges projecting radially inward into contact with said shroud such that a plurality of substantially closed arcuate regions are formed between said annular member and said shroud, said annular member having passages therein providing fluid communication between said plenum and said arcuate regions for supplying cooling air to said arcuate regions, said passages sized to maintain a substantially uniform pressure drop across said shroud during engine operation whereby said shroud is cooled in a substantially uniform manner.

Claim 5

In a gas turbine engine including a compressor, a combustor, and a turbine, fluid cooled turbine apparatus comprising: a row of circumferentially spaCed-apart turbine buckets mounted for rotation about an axis, said turbine buckets extending radially of said axis across an annular passageway for the flow of high temperature motive fluid during engine operation, an annular porous shroud circumferentially surrounding the outer tips of said turbine buckets in closely spaced relationship thereto so as to control leakage of high temperature motive fluid around the tips during engine operation, means for supplying cooling fluid to at least a portion of the outer surface of said shroud during engine operation at a pressure higher than the static pressure exerted on the inner surface of said shroud by high temperature motive fluid in the annular passageway, annular support means radially interposed between said annular shroud and a plenum, located radially outward of said shroud, for supporting said annular shroud, said support means engaging said shroud and having passages therein such that only a portion of the outer surface of said shroud is in fluid communication with said plenum, an annular member circumferentially surrounding said annular shroud and having a first plurality of axially spaced circumferential ridges and a second plurality of circumferentially spaced axial ridges projecting radially inward into contact with said shroud such that a plurality of substantially closed arcuate regions are formed between said annular member and said shroud, said annular member having passages therein providing fluid communication between said plenum and said arcuate regions for supplying cooling air to said arcuate regions, said passages sized to maintain a substantially uniform pressure drop across said shroud during engine operation whereby said shroud is cooled in a substantially uniform manner.

Claim 6

Air cooled turbine apparatus as defined by claim 3 further comprising a layer of abradable material on the inner surface of said shroud, said abradable material having relatively large passages therein for permitting substantially unrestricted flow of cooling air therethrough even subsequent to rubbing between the tips of said turbine buckets and said shroud.