초록

A rotary-wing aircraft includes a retractable port movable between a closed position and an open position to selectively control flow of combustion gases into a bypass passage to change a power distribution between a rotor system and a secondary propulsion system.

대표청구항 ▼

1. A rotary-wing aircraft comprising: a rotor system;a secondary propulsion system transverse to said rotor system;a gas generator operable to generate combustion gases;a first power turbine to receive said combustion gases from said gas generator, said first power turbine operable to drive said rot

1. A rotary-wing aircraft comprising: a rotor system;a secondary propulsion system transverse to said rotor system;a gas generator operable to generate combustion gases;a first power turbine to receive said combustion gases from said gas generator, said first power turbine operable to drive said rotor system;an outer duct downstream of said first power turbine;an inner duct at least partially within said outer duct to define a bypass passage between said inner duct and said outer duct; anda retractable port movable between a closed position and an open position to selectively control flow of said combustion gases into said bypass passage to change a power distribution between said rotor system and said secondary propulsion system, wherein said secondary propulsion system is a pusher propeller. 2. The rotary-wing aircraft as recited in claim 1, wherein said retractable port is defined between a forward duct and said inner duct, said forward duct defined about said gas generator. 3. The rotary-wing aircraft as recited in claim 1, wherein said retractable port is pneumatically operated by compressed bleed air sourced from said gas generator. 4. The rotary-wing aircraft as recited in claim 1, further comprising a gearbox to drive said rotor system, said gearbox driven by said first power turbine. 5. The rotary-wing aircraft as recited in claim 1, wherein said open position windmills said pusher propeller. 6. The rotary-wing aircraft as recited in claim 1, wherein said rotor system is a coaxial contra-rotating rotor system. 7. A rotary-wing aircraft comprising: a rotor system;a secondary propulsion system transverse to said rotor system;a first power turbine operable to drive said rotor system;a second power turbine downstream of said first power turbine, said second power turbine operable to drive said secondary propulsion system; andan exhaust system to couple and uncouple said second power turbine and said first power turbine to change a power distribution between said rotor system and said secondary propulsion system, wherein said secondary propulsion system is a pusher propeller. 8. The rotary-wing aircraft as recited in claim 7, wherein said rotor system is a coaxial contra-rotating rotor system. 9. The rotary-wing aircraft as recited in claim 7, wherein said exhaust system defines a pressure chamber between said second power turbine and said first power turbine. 10. The rotary-wing aircraft as recited in claim 9, further comprising a retractable port in communication with said pressure chamber to effect said pressure change. 11. The rotary-wing aircraft as recited in claim 9, wherein said exhaust system defines a bypass passage in selective communication with said first power turbine. 12. The rotary-wing aircraft as recited in claim 7, wherein said second power turbine includes variable stator vanes. 13. The rotary-wing aircraft as recited in claim 7, wherein said exhaust system further comprises: a forward duct defined about a gas generator to communicate combustion gases from said gas generator to said first power turbine;an outer duct downstream of said first power turbine;an inner duct downstream of said second power turbine, said inner duct at least partially within said outer duct to define a bypass passage between said inner duct and said outer duct; anda retractable port between said forward duct and said inner duct, said retractable port movable between a closed position and an open position, said closed position operable to form a continuous duct for said first power turbine and said second power turbine, and said open position operable to communicate at least a portion of said combustion gases from said first power turbine into said bypass duct. 14. A rotary-wing aircraft comprising: a rotor system;a secondary propulsion system transverse to said rotor system;a gas generator operable to generate combustion gases;a first power turbine to receive said combustion gases, said first power turbine operable to drive said rotor system;an outer duct downstream of said first power turbine;a second power turbine downstream of said first power turbine, said second power turbine operable to drive said secondary propulsion system;an inner duct within said outer duct to define a bypass passage between said inner duct and said outer duct; anda retractable port movable between a closed position and an open position to selectively control flow of said combustion gases from said first power turbine into said bypass passage and change a power distribution between said rotor system and said secondary propulsion system, wherein said secondary propulsion system is a pusher propeller. 15. The rotary-wing aircraft as recited in claim 14, wherein said gas generator includes a gas generator turbine, said gas generator turbine, said first power turbine and said second power turbine along a common axis. 16. The rotary-wing aircraft as recited in claim 15, wherein said gas generator turbine is coupled to a compressor section. 17. The rotary-wing aircraft as recited in claim 6, wherein said coaxial contra rotating rotor system is configured to be driven to produce upward lift. 18. The rotary-wing aircraft as recited in claim 8, wherein said coaxial contra rotating rotor system is driven to produce upward lift. 19. The rotary-wing aircraft as recited in claim 1, wherein said outer duct is entirely downstream of said first power turbine. 20. The rotary-wing aircraft as recited in claim 1, wherein the retractable port in the open position is operable to communicate at least a portion of said combustion gases from said first power turbine into said bypass passage.