Fan variable area nozzle with cable actuator system

摘要

A fan variable area nozzle (FVAN) includes a flap driven through a cable which circumscribes the fan nacelle. The cable is strung through a multiple of flaps to define a flap set of each circumferential sector of the EVAN. An actuator system includes a compact high power density electromechanical actuator which rotates a spool to deploy and retract the cable and effectively increase or decrease the length thereof between the spool and a fixed attachment to increase and decrease the fan nozzle exit area.

主权项

1. A method of providing a variable fan exit area of a high-bypass gas turbine engine comprising the steps of:
(A) locating a fan variable area nozzle to define a fan nozzle exit area for flow passing between a fan nacelle and a core nacelle; (B) stringing a cable to pass through a fan nacelle first fixed engagement structure, then through a flap extension opening and then through a fan nacelle second fixed engagement structure wherein the flap extension opening is located between the first fixed engagement structure and the second fixed engagement structure; (C) locating said flap extension opening in a flap extension protruding from a leading edge of a flap, said flap extension opening upstream of a flap pivot point, said fan nacelle first fixed engagement structure and said fan nacelle second fixed engagement substantially aligned with lateral sides of said flap and at least one of said first and second fixed engagement structures having a cable opening located upstream of said flap pivot point; (D) providing an actuator system that includes a spool engaged with said cable, a segment of said cable opposite said actuator system being attached to a fixed structure within said fan nacelle; (E) spooling and unspooling the cable engaged with said fan variable area nozzle to vary the fan nozzle exit area by pivoting a plurality of said flaps to adjust fan bypass airflow such that an angle of attack of turbofan fan blades are maintained close to design incidence; and (F) wherein unspooling said cable extends the cable to enable said flow to urge a trailing edge of at least one of said plurality of said flaps outwardly and increase said area.