TWO-DIMENSIONAL EXIT NOZZLE FOR AIR-JET ENGINE Russian patent published in 2002 - IPC

FIELD: nozzles for air-jet engines. SUBSTANCE: two dimensional exit nozzle for air-jet engine has body with side walls where upper and lower doors which are rotatable around horizontal axes are located, central body of variable geometry, drive for turning doors and drive for changing geometry of central body. Axis of rotation of doors is shifted from front to rear parts; doors are made in form of hollow box-shaped panels with inlet and outlet slots interconnected by means of through passages. Outlet slots are located not closer than critical section of nozzle. In initial position, slots are sunken relative to inner surface of nozzle body. In turning the doors relative to initial position, inlet slots project above outer surface of nozzle, thus admitting outside air inside doors and mixing it with waste gases. Simultaneously with turn of doors, synchronization mechanism changes geometry of central body ensuring rate of escape of gas from nozzle equal to or lesser than that at initial position of doors. In turning the doors to contact of their rear parts with outer surface of central body, waste gases flow around door and escape through ports thus formed at definite angle towards motion of aircraft; escape of gas at nozzle exit is practically absent, i. e. rate of escape to zero. EFFECT: reduced level of noise during run on runway and low flying speed at noise suppression and thrust reversing when necessary. 2 cl, 3 dwg