Gas turbine engine with variable area fan nozzle bladder system
A turbofan engine includes a variable area fan nozzle which effectively changes the physical area and geometry within a fan bypass flow path to manipulate the pressure ratio of the bypass flow with a multitude of bladders circumferentially located about a core cowl.
1. A gas turbine engine comprising:
a core engine defined about an axis;
a turbofan driven about said axis;
a core cowl defined at least partially about said core engine;
a fan cowl mounted at least partially around said core cowl to define a fan bypass flow path therebetween;
a bladder system within said core cowl, said bladder system movable between a deflated position and an inflated position to selectively vary said fan bypass flow path, said bladder system forms a flush aerodynamic surface with said core cowl when in said deflated position; and
a gear system driven by said core engine, said turbofan driven by said gear system about said axis.
2. The engine as recited in claim 1 , wherein said bladder system includes a single circumferential bladder within said core cowl.
3. The engine as recited in claim 2 , further comprising a control valve system within a bleed air flow communication path to said bladder system.
4. The engine as recited in claim 1 , wherein said bladder system includes a multiple of bladders within said core cowl.
5. The engine as recited in claim 1 , wherein said bladder system is in selective fluid communication with said core engine.
6. The engine as recited in claim 5 , wherein said fluid is a bleed flow from a compressor section.
7. The engine as recited in claim 5 , wherein a bleed flow from said core engine operates to move said bladder system to said inflated position.
8. A gas turbine engine comprising:
a core engine defined about an axis;
a turbofan driven about said axis;
a core cowl defined at least partially about said core engine;
a fan cowl mounted at least partially around said core cowl to define a fan bypass flow path therebetween; and
a bladder system within said core cowl, said bladder system movable between a deflated position and an inflated position to selectively vary said fan bypass flow path, said bladder system forms a flush aerodynamic surface with said core cowl when in said deflated position,
wherein said bladder system includes a multiple of bladders within said core cowl,
wherein each of said multiple of bladders are independently moveably relative said core cowl.
9. The engine as recited in claim 8 , further comprising a controller in communication with a control valve system to independently position each of said multiple of bladders in response to a flight condition.
10. The engine as recited in claim 8 , further comprising a gear system driven by said core engine, said turbofan driven by said gear system about said axis.