Abstract: Embodiments herein describe mitigating flexible modes in an airframe of an aircraft by operating a battery for the aircraft as a tuned mass damper. One embodiment comprises an Unmanned Aerial Vehicle (UAV). The UAV includes a flexible airframe, a plurality of propulsors coupled to the flexible airframe that generate thrust for the UAV, a battery that provides electrical power for the plurality of propulsors, and a suspension system that suspends the battery from the flexible airframe and operates the mass of the battery as a tuned mass damper to dampen flexible modes generated in the flexible airframe during flight.

Abstract: Noise insulation may be provided by an anti-resonant panel that includes a base panel including a base panel core material and two base panel face sheets, where each of the two base panel face sheets is adjacent to an opposite side of the base panel core material. The anti-resonant panel further includes at least one stiffener-member positioned along the base panel in a defined area of the base panel, where the defined area is less than a full area of the base panel. The stiffener-member includes a stiffener-member core having a top surface, a bottom surface in contact with the base panel, a plurality of cells having walls that extend from the top surface to the bottom surface, and a stiffener-member face sheet that is seamlessly integrated with the walls of the plurality of cells along the top surface.

Abstract: Example methods, panels, and systems are disclosed for providing noise insulation. Noise insulation may be provided by an anti-resonant panel that includes a base panel including a base panel core material and two base panel face sheets, where each of the two base panel face sheets is adjacent to an opposite side of the base panel core material. The anti-resonant panel further includes at least one stiffener-member positioned along the base panel in a defined area of the base panel, where the defined area is less than a full area of the base panel. The stiffener-member includes a stiffener-member core material and two stiffener-member face sheets the stiffener-member face sheets adjacent to an opposite side of the stiffener-member core material.

Abstract: A decompression panel assembly for use in an aircraft includes a body panel having an opening defined therein and a cover panel positioned within the opening and spaced from the body panel. The decompression panel assembly also includes an annular spacer panel positioned outboard from the cover panel and the body panel. The spacer panel is spaced from the cover panel to define a first annular flow path between the cover panel and the spacer panel, and the spacer panel is spaced from the body panel to define a second annular flow path between the body panel and the spacer panel.

Abstract: Embodiments herein describe mitigating flexible modes in an airframe of an aircraft by operating a battery for the aircraft as a tuned mass damper. One embodiment comprises an Unmanned Aerial Vehicle (UAV). The UAV includes a flexible airframe, a plurality of propulsors coupled to the flexible airframe that generate thrust for the UAV, a battery that provides electrical power for the plurality of propulsors, and a suspension system that suspends the battery from the flexible airframe and operates the mass of the battery as a tuned mass damper to dampen flexible modes generated in the flexible airframe during flight.

Abstract: Described are methods and systems for broad-band active reduction of noise in target spaces, such as spaces around headrests in aircraft cabins. Systems describe herein are effective over wide frequency ranges without causing undesirable amplification at any subrange ranges. Specifically, a system comprises a speaker and a resonator, both coupled to an enclosure. The interior space of the resonator is in fluid communication with the enclosed space of the enclosure, allowing the resonator to reduce the amplitude of unwanted amplification by the audio reducing sound generated by the speaker. The amplitude is reduced in a selected frequency range, which may correspond to an expected amplification for this particular system. The resonator may partially extend into the enclosure or may be completely incorporated into the enclosure. Some examples of the resonator include a Helmholtz resonator, a passive radiator, a quarter wave resonator, a pipe resonator, and an acoustic metamaterial.

Abstract: A decompression panel assembly for use in an aircraft includes a body panel having an opening defined therein and a cover panel positioned within the opening and spaced from the body panel. The decompression panel assembly also includes an annular spacer panel positioned outboard from the cover panel and the body panel. The spacer panel is spaced from the cover panel to define a first annular flow path between the cover panel and the spacer panel, and the spacer panel is spaced from the body panel to define a second annular flow path between the body panel and the spacer panel.

Abstract: Noise insulation may be provided by an anti-resonant panel that includes a base panel including a base panel core material and two base panel face sheets, where each of the two base panel face sheets is adjacent to an opposite side of the base panel core material. The anti-resonant panel further includes at least one stiffener-member positioned along the base panel in a defined area of the base panel, where the defined area is less than a full area of the base panel. The stiffener-member includes a stiffener-member core having a top surface, a bottom surface in contact with the base panel, a plurality of cells having walls that extend from the top surface to the bottom surface, and a stiffener-member face sheet that is seamlessly integrated with the walls of the plurality of cells along the top surface.

Abstract: Described are methods and systems for broad-band active reduction of noise in target spaces, such as spaces around headrests in aircraft cabins. Systems describe herein are effective over wide frequency ranges without causing undesirable amplification at any subrange ranges. Specifically, a system comprises a speaker and a resonator, both coupled to an enclosure. The interior space of the resonator is in fluid communication with the enclosed space of the enclosure, allowing the resonator to reduce the amplitude of unwanted amplification by the audio reducing sound generated by the speaker. The amplitude is reduced in a selected frequency range, which may correspond to an expected amplification for this particular system. The resonator may partially extend into the enclosure or may be completely incorporated into the enclosure. Some examples of the resonator include a Helmholtz resonator, a passive radiator, a quarter wave resonator, a pipe resonator, and an acoustic metamaterial.

Abstract: Described are methods and systems for broad-band active reduction of noise in target spaces, such as spaces around headrests in aircraft cabins. Systems describe herein are effective over wide frequency ranges without causing undesirable amplification at any subrange ranges. Specifically, a system comprises a speaker and a resonator, both coupled to an enclosure. The interior space of the resonator is in fluid communication with the enclosed space of the enclosure, allowing the resonator to reduce the amplitude of unwanted amplification by the audio reducing sound generated by the speaker. The amplitude is reduced in a selected frequency range, which may correspond to an expected amplification for this particular system. The resonator may partially extend into the enclosure or may be completely incorporated into the enclosure. Some examples of the resonator include a Helmholtz resonator, a passive radiator, a quarter wave resonator, a pipe resonator, and an acoustic metamaterial.

Abstract: Example methods, panels, and systems are disclosed for providing noise insulation. Noise insulation may be provided by an anti-resonant panel that includes a base panel including a base panel core material and two base panel face sheets, where each of the two base panel face sheets is adjacent to an opposite side of the base panel core material. The anti-resonant panel further includes at least one stiffener-member positioned along the base panel in a defined area of the base panel, where the defined area is less than a full area of the base panel. The stiffener-member includes a stiffener-member core material and two stiffener-member face sheets the stiffener-member face sheets adjacent to an opposite side of the stiffener-member core material.

Abstract: A return air bridge for use in an aircraft assembly includes an inboard portion configured to couple to a sidewall assembly at a bottom edge of the sidewall assembly and an outboard portion configured to couple to a structural member. The return air bridge also includes at least one support coupling the inboard portion to the outboard portion such that a return air flow path is defined between the inboard portion and the outboard portion. The outboard portion comprises a plate configured to direct an air flow along the return air flow path upwardly with respect to the bottom edge of the sidewall assembly.

Abstract: A return air bridge for use in an aircraft assembly includes an inboard portion configured to couple to a sidewall assembly at a bottom edge of the sidewall assembly and an outboard portion configured to couple to a structural member. The return air bridge also includes at least one support coupling the inboard portion to the outboard portion such that a return air flow path is defined between the inboard portion and the outboard portion. The outboard portion comprises a plate configured to direct an air flow along the return air flow path upwardly with respect to the bottom edge of the sidewall assembly.

Abstract: There is provided an insulation system and method for a transport vehicle. The system has first and second frame members; a first rigid foam insulation member extending between the first and second frame members; a second rigid foam insulation member, where a first sidewall of the first insulation member integrates with a second sidewall of the second insulation member; and, a third rigid foam insulation member where the second sidewall of the first insulation member integrates with a first sidewall of the third insulation member. Each of the insulation members is surrounded by a protective layer. When the insulation members are integrated, the second and third insulation members impart one or more compression forces on the first insulation member and on the first frame member in order to secure the first insulation member in place without use of any fastener device.

Abstract: There is provided an insulation system and method for a transport vehicle. The system has first and second frame members; a first rigid foam insulation member extending between the first and second frame members; a second rigid foam insulation member, where a first sidewall of the first insulation member integrates with a second sidewall of the second insulation member; and, a third rigid foam insulation member where the second sidewall of the first insulation member integrates with a first sidewall of the third insulation member. Each of the insulation members is surrounded by a protective layer. When the insulation members are integrated, the second and third insulation members impart one or more compression forces on the first insulation member and on the first frame member in order to secure the first insulation member in place without use of any fastener device.

Abstract: Insulation for use in an aircraft fuselage is formed wherein at least one layer made from an open-celled foam that provides acoustic and thermal insulation. The open-celled foam is compression fitted into the airplane fuselage so as to provide effective attachment to the fuselage. The open-celled foam requires minimal attachment treatments. Further, compression fit of the open cell layer is used as an interface around brackets and unrelated hardware to provide superior close-out of gaps that would normally occur using traditional insulation to bracket interfaces. The preferred foam for the open celled compression layer is also relatively moisture resistant (i.e. hydrophobic) in nature and is compressible to between about 0.5 and 10 percent compression, with about 2% compression being ideal for most applications.