Abstract: Sound-attenuating heat exchangers and methods of exchanging heat and attenuating sound within sound-attenuating heat exchangers. The sound-attenuating heat exchangers include a base region, which defines a first base side and a second base side, and a plurality of elongate fluid conduits, which are at least partially defined by the base region and configured to contain a cooled fluid stream. The sound-attenuating heat exchangers also include a plurality of heat transfer-enhancing structures, which extend from the first base side and are configured to exchange thermal energy with a cooling fluid stream, and a sound-attenuating region, which extends from the second base side. The sound-attenuating region includes a plurality of resonator cells configured to attenuate sound and a plurality of resonator cell openings. Each resonator cell opening opens from a corresponding resonator cell toward the plurality of heat transfer-enhancing structures.

Abstract: An acoustic attenuation structure comprises a gas permeable composite facesheet, a cellular core, and an impermeable backing. The gas permeable composite facesheet has a designated porosity. The designated porosity causes the permeability of the gas permeable composite facesheet. The gas permeable composite facesheet comprises a carbon fiber fabric. The cellular core is bonded to the gas permeable composite facesheet using a resin of the gas permeable composite facesheet without any additional adhesive. The impermeable backing is connected to the cellular core.

Abstract: An acoustic insert comprises a sleeve and a number of wave-shaped passageways within the sleeve. A contour of the number of wave-shaped passageways is selected to provide a desired level of attenuation for a frequency of sound waves entering the sleeve.

Abstract: An acoustic insert comprises a sleeve having a first end and a second end. The sleeve comprises segments between the first end and the second end. A first acoustic septum is placed within the sleeve at a first depth. A second acoustic septum placed within the sleeve at a second depth.

Abstract: An acoustic liner having a honeycomb core is fabricated by forming septa in a sheet of material, and assembling the sheet of material and the core. During the assembly process, the septa are respectively inserted as a group into cells of the core.

Abstract: An acoustic insert comprises a sleeve and a number of wave-shaped passageways within the sleeve. A contour of the number of wave-shaped passageways is selected to provide a desired level of attenuation for a frequency of sound waves entering the sleeve.

Abstract: An acoustic attenuation structure comprises a gas permeable composite facesheet, a cellular core, and an impermeable backing. The gas permeable composite facesheet has a designated porosity. The designated porosity causes the permeability of the gas permeable composite facesheet. The gas permeable composite facesheet comprises a carbon fiber fabric. The cellular core is bonded to the gas permeable composite facesheet using a resin of the gas permeable composite facesheet without any additional adhesive. The impermeable backing is connected to the cellular core.

Abstract: An acoustic insert comprises a sleeve having a first end and a second end. The sleeve comprises segments between the first end and the second end. A first acoustic septum is placed within the sleeve at a first depth. A second acoustic septum placed within the sleeve at a second depth.

Abstract: An acoustic assembly includes a backsheet including a plurality of perforations defined therethrough and an acoustic core coupled to the backsheet. The acoustic core includes a plurality of channels defined therethrough that are configured to be in flow communication with the plurality of perforations. The acoustic assembly also includes a linear facesheet coupled to the acoustic core, wherein the linear facesheet includes a plurality of apertures configured to be in flow communication with the plurality of channels. A lipskin is coupled to the linear facesheet, wherein the lipskin includes a plurality of openings configured to be in flow communication with the plurality of apertures.

Abstract: An acoustic liner having a honeycomb core is fabricated by forming septa in a sheet of material, and assembling the sheet of material and the core. During the assembly process, the septa are respectively inserted as a group into cells of the core.

Abstract: An acoustic liner having a honeycomb core is fabricated by forming septa in a sheet of material, and assembling the sheet of material and the core. During the assembly process, the septa are respectively inserted as a group into cells of the core.

Abstract: An acoustic assembly includes a backsheet including a plurality of perforations defined therethrough and an acoustic core coupled to the backsheet. The acoustic core includes a plurality of channels defined therethrough that are configured to be in flow communication with the plurality of perforations. The acoustic assembly also includes a linear facesheet coupled to the acoustic core, wherein the linear facesheet includes a plurality of apertures configured to be in flow communication with the plurality of channels. A lipskin is coupled to the linear facesheet, wherein the lipskin includes a plurality of openings configured to be in flow communication with the plurality of apertures.

Abstract: Systems and methods for acoustic feedback or resonance mitigation are provided. The systems and methods include an exhaust acoustic noise reduction apparatus having an exhaust port comprising an exhaust aperture, a first vane extending at least partially across the exhaust aperture, and a second vane extending at least partially across the exhaust aperture and intersecting the first vane, such that the first and second vanes are oriented to interfere with formation of an acoustic feedback loop and reduce an acoustic noise signature of the exhaust port.

Abstract: An acoustic liner having a honeycomb core is fabricated by forming septa in a sheet of material, and assembling the sheet of material and the core. During the assembly process, the septa are respectively inserted as a group into cells of the core.

Abstract: A composite laminate has a pattern of holes therein. The holes are formed by laying down plies of unidirectional pre-preg material having varying fiber orientations. The tows are spaced apart and located to form holes through the laminate.

Abstract: Systems and methods for acoustic feedback or resonance mitigation are provided. The systems and methods include an exhaust acoustic noise reduction apparatus having an exhaust port comprising an exhaust aperture, a first vane extending at least partially across the exhaust aperture, and a second vane extending at least partially across the exhaust aperture and intersecting the first vane, such that the first and second vanes are oriented to interfere with formation of an acoustic feedback loop and reduce an acoustic noise signature of the exhaust port.