Abstract: A method of controlling plume exhaust heat and/or noise radiation from a turbofan engine assembly having a short nacelle. A mixer duct shell is supported such that a downstream edge of the short nacelle overlays an upstream portion of the mixer duct shell. A first portion of fan exhaust may be routed through the mixer duct shell between its inner surface and an outer surface of a core engine shroud. A second portion of fan exhaust may be routed over an outer surface of the mixer duct shell. At least one of the inner surface and an outer surface of the mixer duct shell may have an acoustic lining including a honeycomb core structure.

Abstract: A method of controlling plume exhaust heat and/or noise radiation from a turbofan engine assembly having a short nacelle. A mixer duct shell is supported such that a downstream edge of the short nacelle overlays an upstream portion of the mixer duct shell. A first portion of fan exhaust may be routed through the mixer duct shell between its inner surface and an outer surface of a core engine shroud. A second portion of fan exhaust may be routed over an outer surface of the mixer duct shell. At least one of the inner surface and an outer surface of the mixer duct shell may have an acoustic lining including a honeycomb core structure.

Abstract: A method of controlling plume exhaust heat and/or noise radiation from a turbofan engine assembly having a short nacelle. A mixer duct shell is supported such that a downstream edge of the short nacelle overlays an upstream portion of the mixer duct shell. A first portion of fan exhaust may be routed through the mixer duct shell between its inner surface and an outer surface of a core engine shroud. A second portion of fan exhaust may be routed over an outer surface of the mixer duct shell. At least one of the inner surface and an outer surface of the mixer duct shell may have an acoustic lining including a honeycomb core structure.

Abstract: 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.

Abstract: 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.

Abstract: A method of controlling plume exhaust heat and/or noise radiation from a turbofan engine assembly having a short nacelle. A mixer duct shell is supported such that a downstream edge of the short nacelle overlays an upstream portion of the mixer duct shell. A first portion of fan exhaust may be routed through the mixer duct shell between its inner surface and an outer surface of a core engine shroud. A second portion of fan exhaust may be routed over an outer surface of the mixer duct shell. At least one of the inner surface and an outer surface of the mixer duct shell may have an acoustic lining including a honeycomb core structure.

Abstract: An airborne mobile platform that has at least one turbofan engine assembly having a fan driven by a core engine, a short nacelle around the fan and a forward portion of the core engine, and a fan exhaust duct through the nacelle. A mixer duct shell is disposed substantially coaxial with and extending forwardly into the fan exhaust duct to provide a mixer duct between the mixer duct shell and a core engine shroud of the core engine. At least a portion of the mixer duct shell has a honeycomb core structure having an inner surface and an outer surface, with an acoustic lining on one of the inner or outer surfaces. The acoustic lining attenuates sound emanating from the turbofan engine assembly.

Abstract: An aircraft configuration that may reduce the level of roaring jet exhaust noise, infrared radiation, sonic boom, or combination thereof directed towards the ground from an aircraft in flight. The aircraft's nacelles are mounted to the aircraft higher than the wings, with substantially vertical stabilizers outboard of the outermost engine. Noise shifting means are provided such as, for each nacelle, primary chevrons at the core nozzle, secondary chevrons at the fan nozzle, a partial bypass mixer, a long duct full flow mixer, or a combination thereof to provide a shift in spectrum distribution of jet exhaust noise from lower to higher frequency. Variable geometry chevrons may be used with increased immersion to provide such a shift just during noise-restricted portions of an aircraft flight profile. The aircraft aerodynamic structural surfaces serve as noise shielding barriers that more effectively block or redirect the frequency shifted noise up and away from communities.

Abstract: An integrated, single piece mixer-center body ventilation apparatus is disclosed for use with a turbofan jet engine. The apparatus may incorporate a circumferential forward body portion adapted to be coupled to an aft end of a core engine turbine case of the jet engine, and a center body tube portion integrally formed with the forward body portion and having an axially opening vent exit. The forward body portion may have a plurality of inner mixer flow paths in communication with scalloped projecting portions. The inner mixer flow paths direct a pressurized core exhaust flow through the mixer device and mix the pressurized core exhaust flow with a portion of a pressurized fan exhaust flow, to thus significantly cool the pressurized core exhaust flow.

Abstract: An aircraft configuration that may reduce the level of roaring jet exhaust noise, infrared radiation, sonic boom, or combination thereof directed towards the ground from an aircraft in flight. The aircraft's nacelles are mounted to the aircraft higher than the wings, with substantially vertical stabilizers outboard of the outermost engine. Noise shifting means are provided such as, for each nacelle, primary chevrons at the core nozzle, secondary chevrons at the fan nozzle, a partial bypass mixer, a long duct full flow mixer, or a combination thereof to provide a shift in spectrum distribution of jet exhaust noise from lower to higher frequency. Variable geometry chevrons may be used with increased immersion to provide such a shift just during noise-restricted portions of an aircraft flight profile. The aircraft aerodynamic structural surfaces serve as noise shielding barriers that more effectively block or redirect the frequency shifted noise up and away from communities.

Abstract: An aircraft configuration that may reduce the level of noise, infrared radiation, or combination thereof directed towards the ground from an aircraft in flight. An embodiment of an aircraft includes a fuselage, two forward swept wings, at least one engine mounted to the aircraft and higher than the wings, and vertical stabilizers mounted on each wing outboard of the outermost engine. The leading edge of the wing may extend forward of the leading end of the engine, and the trailing edge of the aft deck may extend aft of the trailing end of the engine. The aft deck may include an upwardly rotatable pitch control surface at the trailing edge of the deck. Engine types may vary, including but not limited to turbofans, prop-fans, and turbo-props. Main wings may be mounted above the longitudinal axis of the fuselage, and canards may likewise be mounted above or below the axis.

Abstract: An aircraft configuration that may reduce the level of noise, infrared radiation, sonic boom, or combination thereof directed towards the ground from an aircraft in flight. In accordance with an embodiment of the present invention, an aircraft includes a tubular fuselage, two delta wings, at least one engine mounted to the aircraft and higher than the wings, and vertical stabilizers mounted on each wing outboard of the outermost engine. Each wing may include a wing strake at the leading edge of the wing and extending to the fuselage and an aft deck. The leading edge of the wing may extend forward of the intake of the engine, and the trailing edge of the aft deck may extend aft of the engine exhaust. The aft deck may include an upwardly rotatable pitch control surface at the trailing edge of the deck.

Abstract: An integrated, single piece mixer-center body ventilation apparatus is disclosed for use with a turbofan jet engine. The apparatus may incorporate a circumferential forward body portion adapted to be coupled to an aft end of a core engine turbine case of the jet engine, and a center body tube portion integrally formed with the forward body portion and having an axially opening vent exit. The forward body portion may have a plurality of inner mixer flow paths in communication with scalloped projecting portions. The inner mixer flow paths direct a pressurized core exhaust flow through the mixer device and mix the pressurized core exhaust flow with a portion of a pressurized fan exhaust flow, to thus significantly cool the pressurized core exhaust flow.

Abstract: An airborne mobile platform that has at least one turbofan engine assembly having a fan driven by a core engine, a short nacelle around the fan and a forward portion of the core engine, and a fan exhaust duct through the nacelle. A mixer duct shell is disposed substantially coaxial with and extending forwardly into the fan exhaust duct to provide a mixer duct between the mixer duct shell and a core engine shroud of the core engine. At least a portion of the mixer duct shell has a honeycomb core structure having an inner surface and an outer surface, with an acoustic lining on one of the inner or outer surfaces. The acoustic lining attenuates sound emanating from the turbofan engine assembly.

Abstract: A thermal radiation-generating decoy mounted adjacent an aircraft engine structure, such as an engine nacelle, includes a heat source inside of an aerodynamic enclosure with a mounting interface to attach the enclosure to the engine structure. The decoy can further be located at the lower extreme of and adjacent the forward-most portion of the engine nacelle in order to attract an infrared-seeking threat to the vicinity of the fan containment portion of the engine nacelle. The decoy can be designed to have a thermal signature that mimics a scaled overall aircraft thermal signature. In addition, the decoy can include a fuse shield adjacent the enclosure to detonate a threat in the case that the threat approach trajectory is imprecise and the threat bypasses the enclosure within an aspect of the fuse shield as viewed from the approach direction of the threat.

Abstract: An aircraft configuration that may reduce the level of noise, infrared radiation, or combination thereof directed towards the ground from an aircraft in flight. An embodiment of an aircraft includes a fuselage, two forward swept wings, at least one engine mounted to the aircraft and higher than the wings, and vertical stabilizers mounted on each wing outboard of the outermost engine. The leading edge of the wing may extend forward of the leading end of the engine, and the trailing edge of the aft deck may extend aft of the trailing end of the engine. The aft deck may include an upwardly rotatable pitch control surface at the trailing edge of the deck. Engine types may vary, including but not limited to turbofans, prop-fans, and turbo-props. Main wings may be mounted above the longitudinal axis of the fuselage, and canards may likewise be mounted above or below the axis.

Abstract: An aircraft configuration that may reduce the level of noise, infrared radiation, or combination thereof directed towards the ground from an aircraft in flight. An embodiment of an aircraft includes a fuselage, two forward swept wings, at least one engine mounted to the aircraft and higher than the wings, and vertical stabilizers mounted on each wing outboard of the outermost engine. The leading edge of the wing may extend forward of the leading end of the engine, and the trailing edge of the aft deck may extend aft of the trailing end of the engine. The aft deck may include an upwardly rotatable pitch control surface at the trailing edge of the deck. Engine types may vary, including but not limited to turbofans, prop-fans, and turbo-props. Main wings may be mounted above the longitudinal axis of the fuselage, and canards may likewise be mounted above or below the axis.

Abstract: An aircraft includes at least one turbofan engine assembly having a shrouded core engine, a short nacelle surrounding a fan and a forward portion of the core engine, and a fan exhaust duct through the nacelle. A mixer duct shell is positioned substantially coaxial with the engine shroud and extends forwardly into the fan duct to provide an interstitial mixer duct between the mixer duct shell and the core engine shroud. The aft portion of the mixer duct shell extends over a turbine exhaust frame, an attached mixer (if included), and a tail cone exhaust plug. The mixer duct shell can reduce noise and plume exhaust heat radiated from aircraft turbofan engines.

Abstract: A thermal radiation-generating decoy mounted adjacent an aircraft engine structure, such as an engine nacelle, includes a heat source inside of an aerodynamic enclosure with a mounting interface to attach the enclosure to the engine structure. The decoy can further be located at the lower extreme of and adjacent the forward-most portion of the engine nacelle in order to attract an infrared-seeking threat to the vicinity of the fan containment portion of the engine nacelle. The decoy can be designed to have a thermal signature that mimics a scaled overall aircraft thermal signature. In addition, the decoy can include a fuse shield adjacent the enclosure to detonate a threat in the case that the threat approach trajectory is imprecise and the threat bypasses the enclosure within an aspect of the fuse shield as viewed from the approach direction of the threat.