Bifurcated turbofan nozzle
AssigneeThe NORDAM Group, Inc.
InventorJean-Pierre Lair
Life of this patent
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Abstract
A turbofan exhaust nozzle includes a fan duct defined between a fan nacelle and a core engine cowling. The fan duct includes a longitudinal endwall and a partition spaced therefrom to define a secondary flow duct. The fan duct also includes a primary outlet, and the secondary duct includes a secondary outlet. The partition between the two ducts includes an aperture covered by a selectively movable flap.
Claims25
A turbofan exhaust nozzle comprising:
- a fan nacelle surrounding a core cowling to define an arcuate fan duct radially therebetween for discharging fan air;
- said fan duct including a longitudinal endwall interrupting circumferential continuity thereof, and a partition spaced from said endwall to define a secondary flow duct;
- said fan duct having an arcuate primary outlet disposed radially between said cowling and a trailing edge of said nacelle, and said secondary duct having a secondary outlet disposed between said cowling and nacelle trailing edge;
- and
- said partition including an aperture covered by a movable flap.
A turbofan exhaust nozzle comprising:
- a fan nacelle surrounding a core engine cowling with arcuate portions joined together at circumferentially opposite endwalls to define a pair of C-shaped fan ducts for discharging fan air therefrom;
- each of said fan ducts including a partition spaced from one of said endwalls to define a corresponding pair of secondary flow ducts;
- said pair of fan ducts having corresponding primary outlets disposed radially between said cowling and a trailing edge of said nacelle;
- said pair of secondary ducts having corresponding secondary outlets adjoining said primary outlets;
- said partitions including respective apertures covered by corresponding flaps;
- and
- means for selectively moving said flaps between stowed and deployed positions for correspondingly blocking and unblocking said partition apertures.
A method of reducing noise in a turbofan engine having a fan discharging fan air through a fixed flow area outlet in a fan nozzle defined between a fan nacelle and core engine cowling comprising increasing circumferential extent of outlet flow area in said fan nozzle during takeoff operation of said engine for correspondingly reducing velocity of said fan air being discharged therefrom, and terminating said area increase at cruise operation of said engine at altitude.
Dependencies are inferred from the claim text.