Abstract: There is provided an acoustically treated landing gear door for reducing noise from a landing gear of an aircraft. The acoustically treated landing gear door includes a landing gear door for attachment to the aircraft. The landing gear door includes an acoustic treatment assembly integrated on an inner mold line of an interior side, and extending within an interior cavity of the landing gear door. The acoustic treatment assembly includes a core structure having a first side and a second side, a plurality of core cells extending between the first side and the second side, and a drainage system. The acoustic treatment assembly further includes an acoustic facesheet and a nonporous backsheet. The acoustically treated landing gear door reduces the noise from the landing gear, when the landing gear is in a deployed position, by attenuating acoustic waves emanating from the landing gear and reflected off the acoustic treatment assembly.

Abstract: There is provided an acoustically treated landing gear door for reducing noise from a landing gear of an aircraft. The acoustically treated landing gear door includes a landing gear door for attachment to the aircraft. The landing gear door includes an acoustic treatment assembly integrated on an inner mold line of an interior side, and extending within an interior cavity of the landing gear door. The acoustic treatment assembly includes a core structure having a first side and a second side, a plurality of core cells extending between the first side and the second side, and a drainage system. The acoustic treatment assembly further includes an acoustic facesheet and a nonporous backsheet. The acoustically treated landing gear door reduces the noise from the landing gear, when the landing gear is in a deployed position, by attenuating acoustic waves emanating from the landing gear and reflected off the acoustic treatment assembly.

Abstract: Systems and methods are provided for an inductive coil anti-icing and noise absorption system. In certain versions, the inductive coil anti-icing and noise absorption system may include an inductive coil and a skin. The inductive coil may generate electromagnetic fields and may electromagnetically couple with the skin. The skin, upon electromagnetically coupling with the inductive coil, may increase in temperature and the increase in temperature may melt or prevent the formation of ice on the skin. The skin or a portion of the skin may be porous and may allow incorporation of a sound absorbing liner. The sound absorbing liner may attenuate noise generated by the aircraft (e.g., noise generated by the aircraft engine). Certain versions may include a plurality of inductive coils and a plurality of skins.

Abstract: Systems and methods are provided for an inductive coil anti-icing and noise absorption system. In certain versions, the inductive coil anti-icing and noise absorption system may include an inductive coil and a skin. The inductive coil may generate electromagnetic fields and may electromagnetically couple with the skin. The skin, upon electromagnetically coupling with the inductive coil, may increase in temperature and the increase in temperature may melt or prevent the formation of ice on the skin. The skin or a portion of the skin may be porous and may allow incorporation of a sound absorbing liner. The sound absorbing liner may attenuate noise generated by the aircraft (e.g., noise generated by the aircraft engine). Certain versions may include a plurality of inductive coils and a plurality of skins.

Abstract: An aircraft auxiliary power unit sound attenuation apparatus includes a perforated body having a center aperture through which exhaust fluid passes, a backing member outwardly offset from the perforated body, a plurality of connecting members coupling the perforated body to the backing member to form a locally reacting sound attenuation member having a plurality of channels spanning outwardly from the perforated body to the backing member, and a bulk absorber disposed in each of the plurality of channels where the bulk absorber is in fluid communication with the exhaust fluid, where the locally reacting sound attenuation member is in fluid communication with an auxiliary power unit of an aircraft so that the plurality of channels are oriented in a direction crossing a pressure drop direction of an exhaust fluid flow passing through the center aperture and each channel circumscribes the center aperture.

Abstract: An aircraft engine sound attenuation apparatus includes a perforated face member, a backing member, a plurality of connecting members coupling the perforated face member to the backing member to form a plurality of channels spanning from the perforated face member to the backing member, and a bulk absorber disposed in each of the plurality of channels, wherein the plurality of channels are connected to an interior portion of an aircraft engine nacelle component so that the plurality of channels are oriented in a direction substantially normal to a direction of fluid flow pressure drop passing through the aircraft engine.

Abstract: An aircraft auxiliary power unit sound attenuation apparatus includes a perforated body having a center aperture through which exhaust fluid passes, a backing member outwardly offset from the perforated body, a plurality of connecting members coupling the perforated body to the backing member to form a locally reacting sound attenuation member having a plurality of channels spanning outwardly from the perforated body to the backing member, and a bulk absorber disposed in each of the plurality of channels where the bulk absorber is in fluid communication with the exhaust fluid, where the locally reacting sound attenuation member is in fluid communication with an auxiliary power unit of an aircraft so that the plurality of channels are oriented in a direction crossing a pressure drop direction of an exhaust fluid flow passing through the center aperture and each channel circumscribes the center aperture.

Abstract: An aircraft auxiliary power unit sound attenuation apparatus includes a perforated body having a center aperture through which exhaust fluid passes, a backing member outwardly offset from the perforated body, a plurality of connecting members coupling the perforated body to the backing member to form a locally reacting sound attenuation member having a plurality of channels spanning outwardly from the perforated body to the backing member, and a bulk absorber disposed in each of the plurality of channels where the bulk absorber is in fluid communication with the exhaust fluid, where the locally reacting sound attenuation member is in fluid communication with an auxiliary power unit of an aircraft so that the plurality of channels are oriented in a direction crossing a pressure drop direction of an exhaust fluid flow passing through the center aperture and each channel circumscribes the center aperture.

Abstract: Systems and methods are provided for an inductive coil anti-icing and noise absorption system. In certain versions, the inductive coil anti-icing and noise absorption system may include an inductive coil and a skin. The inductive coil may generate electromagnetic fields and may electromagnetically couple with the skin. The skin, upon electromagnetically coupling with the inductive coil, may increase in temperature and the increase in temperature may melt or prevent the formation of ice on the skin. The skin or a portion of the skin may be porous and may allow incorporation of a sound absorbing liner. The sound absorbing liner may attenuate noise generated by the aircraft (e.g., noise generated by the aircraft engine). Certain versions may include a plurality of inductive coils and a plurality of skins.

Abstract: Systems and methods are provided for an inductive coil anti-icing and noise absorption system. In certain versions, the inductive coil anti-icing and noise absorption system may include an inductive coil and a skin. The inductive coil may generate electromagnetic fields and may electromagnetically couple with the skin. The skin, upon electromagnetically coupling with the inductive coil, may increase in temperature and the increase in temperature may melt or prevent the formation of ice on the skin. The skin or a portion of the skin may be porous and may allow incorporation of a sound absorbing liner. The sound absorbing liner may attenuate noise generated by the aircraft (e.g., noise generated by the aircraft engine). Certain versions may include a plurality of inductive coils and a plurality of skins.

Abstract: An aircraft auxiliary power unit sound attenuation apparatus includes a perforated body having a center aperture through which exhaust fluid passes, a backing member outwardly offset from the perforated body, a plurality of connecting members coupling the perforated body to the backing member to form a locally reacting sound attenuation member having a plurality of channels spanning outwardly from the perforated body to the backing member, and a bulk absorber disposed in each of the plurality of channels where the bulk absorber is in fluid communication with the exhaust fluid, where the locally reacting sound attenuation member is in fluid communication with an auxiliary power unit of an aircraft so that the plurality of channels are oriented in a direction crossing a pressure drop direction of an exhaust fluid flow passing through the center aperture and each channel circumscribes the center aperture.

Abstract: An aircraft engine sound attenuation apparatus includes a perforated face member, a backing member, a plurality of connecting members coupling the perforated face member to the backing member to form a plurality of channels spanning from the perforated face member to the backing member, and a bulk absorber disposed in each of the plurality of channels, wherein the plurality of channels are connected to an interior portion of an aircraft engine nacelle component so that the plurality of channels are oriented in a direction substantially normal to a direction of fluid flow pressure drop passing through the aircraft engine.

Abstract: An acoustic panel for sound attenuation employs a septumized cellular core sandwiched between a backsheet and a linear acoustic facesheet. The linear acoustic facesheet employs a linear material layer that impedes acoustic waves entering the core substantially linearly over a wide range of frequencies and sound of pressure levels.

Abstract: An arcuate or semi-circumferential shield in the shape of a visor that is adapted to be secured to an external surface of a nozzle housing of a jet nozzle to attenuate jet noise generated by the jet nozzle. The shield may be fixedly secured to the nozzle housing or movably supported so that it can be moved between retracted and deployed positions. When used as a fixedly mounted component, or when positioned in its deployed position, a downstream edge of the shield extends past a downstream edge of the nozzle housing and the shield is spaced apart from an outer surface of the nozzle housing to form a channel therebetween. The shield is preferably orientated at approximately a bottom dead center of the nozzle housing. The shield operates to attenuate jet installation noise, and particularly jet installation noise experienced during the takeoff phase of flight of a jet aircraft, as well as to reduce jet installation noise that would otherwise propagate forwardly toward the cockpit of the aircraft.

Abstract: An arcuate or semi-circumferential shield in the shape of a visor that is adapted to be secured to an external surface of a nozzle housing of a jet nozzle to attenuate jet noise generated by the jet nozzle. The shield may be fixedly secured to the nozzle housing or movably supported so that it can be moved between retracted and deployed positions. When used as a fixedly mounted component, or when positioned in its deployed position, a downstream edge of the shield extends past a downstream edge of the nozzle housing and the shield is spaced apart from an outer surface of the nozzle housing to form a channel therebetween. The shield is preferably orientated at approximately a bottom dead center of the nozzle housing. The shield operates to attenuate jet installation noise, and particularly jet installation noise experienced during the takeoff phase of flight of a jet aircraft, as well as to reduce jet installation noise that would otherwise propagate forwardly toward the cockpit of the aircraft.

Abstract: An exhaust flow nozzle for a jet engine having a plurality of flow altering components extending from a lip portion of a secondary exhaust nozzle that are movable between first and second positions. In the first position the flow altering components are disposed substantially parallel to an exhaust gas flow path and thereby do not produce drag or a reduction of thrust from the engine. In the second position the flow altering components bend or are deformed to project into the exhaust gas flow path exiting from the secondary exhaust nozzle. The flow altering components are comprised of a shape-memory alloy material which deforms in response to heat. One or more additional layers of material are bonded or otherwise coupled to the shape-memory alloy layer of each flow altering component to assist in returning the shape-memory alloy layer to its unheated shape.

Abstract: An exhaust flow nozzle for a jet engine having a plurality of flow altering components extending from a lip portion of a secondary exhaust nozzle that are movable between first and second positions. In the first position the flow altering components are disposed substantially parallel to an exhaust gas flow path and thereby do not produce drag or a reduction of thrust from the engine. In the second position the flow altering components bend or are deformed to project into the exhaust gas flow path exiting from the secondary exhaust nozzle. The flow altering components are comprised of a shape-memory alloy material which deforms in response to heat. One or more additional layers of material are bonded or otherwise coupled to the shape-memory alloy layer of each flow altering component to assist in returning the shape-memory alloy layer to its unheated shape.

Abstract: A flow control device and method for eliminating flow-induced cavity resonance within a closed or nearly closed end flow passage (20) having an inlet opening (30) defined between an upstream inlet edge (32) and a downstream inlet edge (34). The passage accepts exterior fluid flow (38) therein via the opening (30). The flow control device includes a stationary inlet guide vane (44) having a leading edge (46), a trailing edge (48), and a number of support members (50) to connect the vane to the inlet. The vane (44) is positioned such that the vane leading edge intercepts the exterior fluid flow shear layer, and the vane trailing edge extends into the passage at the inlet. In a preferred embodiment, the inlet guide vane is located approximately midway between the upstream and downstream inlet edges. The inlet guide vane is cross-sectionally shaped as a cambered airfoil.