The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 27, 1998
Filed:
Feb. 28, 1997
Peter K Rudolph, Seattle, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
An engine exhaust nozzle (36) is provided for reducing exhaust noise in an intermediate bypass ratio turbofan engine. The nozzle (36) includes a plurality of scoop ejectors (38) placed equal distances about the circumference of a nozzle outer structure (46). A translatable centerbody (52) is located within the outer structure (46). The annular space between the outer structure (46) and the centerbody (52) define a convergent-divergent exhaust duct (56). Each scoop ejector (38) has a forward inlet (71) and an aft outlet (72). The scoop ejectors are rotatably connected to the outer structure (46) at a pivot point located approximately midway along the ejectors. The axes of rotation (82) of the scoop ejectors lie transverse to the nozzle longitudinal centerline. In an open position, the scoop ejectors are rotated so that the inlets (71) extend into the ambient airstream and the outlets (72) extend into the exhaust duct (56). Aft nozzle flaps (114) are used to form the rearmost portions of the nozzle (36). During noise suppression, the scoop ejectors (38) are rotated open to allow ambient air (40) to enter the exhaust duct (56) at aspiration ratios of generally less than 40% of the engine exhaust (42). When noise suppression is not needed, the scoop ejectors (38) are closed by rotating them so that the inlet (71) is flush with the exterior surface (48) and the outlet (72) is in a sealed and flush contact with the inner duct wall (50).