TURBOFAN ENGINE WITH VARIABLE EXHAUST COOLING

摘要

Disclosed aircraft and turbofan engines have an active configuration (corresponding to flight, etc.) and an idle configuration (corresponding to ground idle). Turbofan engines comprise a core engine, a nacelle, a bypass duct therebetween, and a bypass splitter shell that extends at least partially between the nacelle and the core engine to define peripheral and interstitial bypass ducts. Bypass flow in the bypass duct splits into peripheral bypass flow and interstitial bypass flow. The relatively cool, slow interstitial bypass flow is directed into relatively hot, fast core exhaust flow from the core engine and into a mixed exhaust duct at least partially defined by the bypass splitter shell. The bypass splitter shell may be selectively positioned to increase (in the idle configuration) or to decrease (in the active configuration) the relative flow of the interstitial bypass flow, thereby cooling and/or slowing the mixed exhaust flow in the idle configuration.

主权项

1. A turbofan engine comprising:
a core engine with a core engine shroud and a core exhaust duct; a nacelle radially surrounding at least a fore portion of the core engine; a bypass duct defined between the nacelle and the core engine shroud; a bypass splitter shell substantially coaxial with the nacelle and the core engine, wherein the bypass splitter shell includes a trailing edge outside of the nacelle and a leading edge that extends to the bypass duct to define a peripheral bypass duct between the bypass splitter shell and the nacelle, and to define an interstitial bypass duct between the bypass splitter shell and the core engine shroud; and an actuator coupled to the bypass splitter shell and configured to axially translate the bypass splitter shell between an idle configuration with a first inlet area of the interstitial bypass duct and an active configuration with a second inlet area of the interstitial bypass duct, wherein the first inlet area is greater than the second inlet area.