Abstract: A cascade thrust reverser for use with a mixer/ejector noise suppressor has a set of internal blocker doors controllably moveable between a stowed position, where engine exhaust passes through and out the tailpipe, and a deployed position, where engine exhaust is blocked and redirected out a pair of cascades or louvers. External cascade doors cover the cascades from the outside during flight, but are moved aft, exposing the cascades, when the blocker doors are deployed subsequent landing. In a preferred embodiment, the cascade doors and the blocker doors are interconnected through a pair of actuation mechanisms, whereby movement of the cascade doors is sequenced to the motion of the blocker doors. The blocker doors and the cascade doors are shaped to provide a clean aerodynamic profile when stowed, so that the noise suppressor functions optimally. The actuation mechanisms also preferably include lock mechanisms for only allowing the thrust reversers to be deployed just subsequent landing.

Abstract: A contoured thrust reverser and lobed nozzle noise suppressor is meant for use with gas turbine engines that have conventional post-exit thrust reversers and that require only moderate levels of noise suppression. The contoured thrust reverser and lobed nozzle noise suppressor comprises a conventional tailpipe frame terminating in a lobed nozzle, and a conventional thrust reverser mechanism holding a pair of contoured blocker doors. In a deployed position, the blocker doors lie aft of the lobed nozzle, having been moved there by the thrust reverser mechanism. The blocker doors abut one another and form a fore-facing scoop, wherein any engine exhaust exiting the lobed nozzle is redirected towards the fore of the engine. In a stowed position, the blocker doors lie over the tailpipe frame and align and nestle together with the engine's cowling.

Abstract: A mixer/ejector suppressor is disclosed for reducing the noise level created by the exhaust flows in gas turbines. In the preferred embodiment, the suppressor comprises a mixing ring of alternating lobes attached to the engine's tailpipe; an ejector shroud mounted onto the mixing ring; and a plurality of arcuate gaps, between the mixing ring and ejector shroud, that permit ambient air to be entrained into the shroud. The preferred mixing ring has ten curved lobes of alternating designs. Five of the mixing lobes are shallow, with contours similar to those of mixing lobes in an earlier TSMEC version, disclosed in a related U.S. utility patent application, Ser. No. 08/729,571. The other five lobes are much longer, and they are designed to penetrate deeply into the engine's hot core flow. Together, the ten lobes rapidly mix (mostly at supersonic conditions) the engine exhaust flows with secondary ambient air inside the shroud.

Abstract: A two-stage mixer ejector concept ("TSMEC") is disclosed for suppressing the noise emanated by jet aircraft. This TSMEC was designed to help older engines meet the stringent new federal noise regulations, known as "Stage III". In an illustrated embodiment, the TSMEC comprises: a lobed engine nozzle attached to the rear of a turbofan engine; a short shroud that straddles the exit end of the engine nozzle; two rings of convergent/divergent primary and secondary lobes within the engine nozzle shroud and; and a ring of arcuate gaps that precede the shroud and the second nozzle ring. The lobes are complimentary shaped to rapidly mix the turbine's hot exhaust flow with cooler air including entrained ambient air, at supersonic speed. This drastically reduces the jet exhaust's velocity and increases jet mixing, thereby reducing the jet noise.