초록 ▼

A gas turbine engine including an outer case and an exhaust gas passage defined within the outer case for conducting an exhaust gas flow from a turbine section of the gas turbine engine. A cooling channel is associated with an outer surface of the outer case, the cooling channel having a channel inl

A gas turbine engine including an outer case and an exhaust gas passage defined within the outer case for conducting an exhaust gas flow from a turbine section of the gas turbine engine. A cooling channel is associated with an outer surface of the outer case, the cooling channel having a channel inlet and a channel outlet. An air duct structure is provided and includes an inlet end in fluid communication with the channel outlet and includes an outlet end in fluid communication with an area of reduced pressure relative to the air duct structure inlet end. An exit cavity is located at the air duct structure outlet end, wherein the exit cavity effects a reduced pressure at the outlet end to draw air from the cooling channel into the air duct.

대표청구항 ▼

1. A gas turbine engine comprising: an outer case comprising a turbine exhaust case defining a central longitudinal axis, the exhaust case having an upstream exhaust flange, a downstream exhaust flange, and an outer surface between the upstream and downstream exhaust flanges, the upstream and downst

1. A gas turbine engine comprising: an outer case comprising a turbine exhaust case defining a central longitudinal axis, the exhaust case having an upstream exhaust flange, a downstream exhaust flange, and an outer surface between the upstream and downstream exhaust flanges, the upstream and downstream exhaust flanges extending radially outward from the outer surface of said exhaust case,the outer case comprising a spool structure comprising an upstream spool flange attached to the downstream exhaust flange, a downstream spool flange, and an outer surface between the upstream and downstream spool flanges, the upstream and downstream spool flanges extending radially outward from the outer surface of said spool structure, the outer surface of said outer case defined by the outer surfaces of exhaust case and the spool structure and extends circumferentially around the central longitudinal axis;an exhaust gas passage defined within the outer case, the exhaust gas passage including an outer duct wall and an inner duct wall forming an annular passage and located radially inward from the outer case for conducting an exhaust gas flow from a turbine section of the gas turbine engine;a cooling channel associated with the outer surface of said outer case, said cooling channel having a channel inlet and a channel outlet;a panel structure extending circumferentially around said outer case and comprising an upstream end affixed at the upstream exhaust flange and downstream end affixed at the downstream spool flange, said panel structure is radially spaced away from said outer surface to define said cooling channel between the panel structure and the outer case;an air duct structure including an inlet end in fluid communication with said channel outlet and an outlet end in fluid communication with an area of reduced pressure relative to said air duct structure inlet end; andan exit cavity at said air duct structure outlet end, said exit cavity effecting a reduced pressure at said outlet end to draw air from said cooling channel into said air duct,wherein ambient air passes through said panel structure and enters said cooling channel, andwherein said panel structure comprises plural panel sections with axially extending gaps defined between adjacent panel sections at spaced circumferential locations, said gaps permitting passage of ambient air into said cooling channel. 2. The gas turbine engine of claim 1, wherein said air duct structure comprises a passage extending from an inner surface of said outer case to a location of said exit cavity radially inwardly of said exhaust gas passage. 3. The turbine engine of claim 2, including a strut extending radially inward from said inner surface of said outer case, and said air duct structure is defined by a radiation shield extending around said strut and attached to said inner surface of said outer case. 4. The gas turbine engine of claim 3, including openings through said outer case defining said cooling channel outlet for conducting ambient air from said outer surface of said outer case to said air duct structure. 5. The gas turbine engine of claim 1, including openings through said outer case defining said cooling channel outlet for conducting ambient air from said outer surface of said outer case to said air duct structure. 6. The gas turbine engine of claim 1, including a thermal barrier/cooling system for controlling a temperature of the outer case, said thermal barrier/cooling system including: an internal insulating layer supported on an inner surface of said outer case opposite said outer surface of said outer case, the internal insulating layer extending circumferentially along said inner surface of said outer case and providing a thermal resistance to radiated energy from said exhaust gas passage located radially inwardly from said outer case; andsaid cooling channel being generally axially aligned with said internal insulating layer and forming a flow path for an ambient air flow cooling said outer surface of said outer case. 7. The gas turbine engine of claim 6, including an external insulating layer supported on and covering said panel structure. 8. The gas turbine engine of claim 6, including an exhaust diffuser defining said exhaust gas passage at said axial location of said internal insulating layer. 9. A gas turbine engine including an exhaust section comprising: an outer case defining a central longitudinal axis, and an outer case having an upstream flange and a downstream flange and an exterior surface extending circumferentially between the upstream and downstream flanges around the central longitudinal axis, the upstream and downstream flanges extending radially outward from the exterior surface of said outer case;a panel structure extending circumferentially around said outer case and having upstream and downstream ends affixed to said exhaust section, said panel structure is radially spaced away from said exterior surface to define a cooling channel and said exterior surface; an exhaust duct located within said outer case and defined between an outer duct wall and an inner duct wall, said exhaust duct defining a passage for hot exhaust gases flowing in an axially downstream direction and exiting a turbine section of said gas turbine engine;a rear bearing housing located radially inward from said inner duct wall;a strut extending from said outer case to said bearing housing;a shield structure surrounding said strut to shield said strut from said exhaust gases;an air opening formed through said outer case exterior surface in fluid communication with said cooling channel, said air opening being in fluid communication with a radial passage extending between said strut and a portion of said shield structure; anda disk cavity located adjacent a stage of said turbine section and in fluid communication with said radial passage, said disk cavity being at a pressure lower than an ambient air pressure outside of said turbine engine for effecting a flow of ambient air through said air opening into said disk cavity, wherein ambient air entering said air opening passes through said panel structure and into said cooling channel, and wherein said cooling channel extends circumferentially around said outer case, and said panel structure comprises plural panel sections with axially extending gaps defined between adjacent panel sections at spaced circumferential locations, said gaps permitting passage of ambient air into said channel. 10. The gas turbine engine of claim 9, wherein said shield structure includes a strut shield surrounding said strut and a radiation shield located between said strut shield and said strut. 11. The gas turbine engine of claim 10, wherein said radial passage is defined by an interior surface of said radiation shield and an exterior surface of said strut. 12. The gas turbine engine of claim 11, wherein said radiation shield extends through an annular space defined between said outer duct wall and said outer case. 13. The gas turbine engine of claim 12, wherein said radiation shield includes a radially outer end attached to an interior surface of said outer case and surrounding said air opening. 14. The gas turbine engine of claim 9, including a tunnel cavity defined radially inward from said inner duct wall and located in the axial downstream direction from said disk cavity, said tunnel cavity receiving said ambient air prior to said ambient air entering said disk cavity. 15. The gas turbine engine of claim 9, including a thermal barrier/cooling system for controlling a temperature of the outer case, said thermal barrier/cooling system including: an internal insulating layer supported on an inner surface of said outer case opposite said outer surface of said outer case, the internal insulating layer extending circumferentially along said inner surface of said outer case and providing a thermal resistance to radiated energy from said exhaust gas passage located radially inwardly from said outer case; andsaid cooling channel being generally axially aligned with said internal insulating layer and forming a flow path for an ambient air flow cooling said outer surface of said outer case. 16. The gas turbine engine of claim 15, including an external insulating layer supported on and covering said panel structure. 17. The gas turbine engine of claim 15, including an exhaust diffuser defining said exhaust gas passage at said axial location of said internal insulating layer. 18. A gas turbine engine comprising: an outer case defining a central longitudinal axis, and the outer case defining an surface extending circumferentially around the central longitudinal axis;an exhaust gas passage defined within the outer case for conducting an exhaust gas flow from a turbine section of the gas turbine engine;a cooling channel defined between the outer surface of said outer case and a panel structure supported on said outer case, said cooling channel having a channel inlet and a channel outlet;said panel structure comprises plural panel sections with axially extending gaps defined between adjacent panel sections at spaced circumferential locations, said gaps permitting passage of ambient air into said cooling channel;an air duct structure including an inlet end in fluid communication with said channel outlet and an outlet end in fluid communication with an area of reduced pressure relative to said air duct structure inlet end; andan exit cavity at said air duct structure outlet end, said exit cavity effecting a reduced pressure at said outlet end to draw air from said cooling channel into said air duct.