Abstract: An apparatus is provided that includes a structure. This structure includes a first skin, a second skin and a cellular core connected to the first skin and the second skin. The cellular core includes a cantilevered damper and an internal cavity between the first skin and the second skin. The cantilevered damper projects into the internal cavity. The cantilevered damper includes a plurality of damper masses and a plurality of damper arms interconnecting the plurality of damper masses together.

Abstract: An additively manufactured noise attenuation panel for a structure within an aircraft structure includes a plurality of unit cells, each including a central body interconnected via a plurality of tubes extending from the central body. The noise attenuation panel may include an increasing wall thickness in a desired direction. A layers of unit cells may be manufactured in a twisted orientation with respect to an immediately adjacent layer of unit cells. Layers of unit cells may be manufactured in a rounded or bent orientation with respect to a central axis. The noise attenuation panel may further comprise a disk and a blended transition located at the interface between the disk and an interior surface of a unit cell.

Abstract: An engine assembly includes a combustor wall with a first skin, a second skin, a core and a sound attenuation passage. The first skin forms a peripheral boundary of a combustion volume on a first side of the combustor wall. The second skin forms a peripheral boundary of a plenum on a second side of the combustor wall. The core includes a plurality of resonator elements between the first skin and the second skin. A first resonator element includes a first base and a plurality of first protrusions projecting out from the first base. Each first protrusion includes a first bore fluidly coupled with a first cavity within the first base. The sound attenuation passage extends within the core and is fluidly coupled with the combustion volume through an attenuation passage aperture in the first skin. The sound attenuation passage is fluidly decoupled from the plenum by the second skin.

Abstract: An engine assembly includes a combustor wall with a first skin, a second skin, a core and a sound attenuation passage. The first skin forms a peripheral boundary of a combustion volume on a first side of the combustor wall. The second skin forms a peripheral boundary of a plenum on a second side of the combustor wall. The core includes a plurality of resonator elements between the first skin and the second skin. A first resonator element includes a first base and a plurality of first protrusions projecting out from the first base. Each first protrusion includes a first bore fluidly coupled with a first cavity within the first base. The sound attenuation passage extends within the core and is fluidly coupled with the combustion volume through an attenuation passage aperture in the first skin. The sound attenuation passage is fluidly decoupled from the plenum by the second skin.

Abstract: An acoustic supercell may comprise a facesheet having a plurality of perforations, a backplate parallel to the facesheet, a cell wall contacting the facesheet and the back plate, and a periodic structure. The supercell may be custom-tailored to meet specific acoustic wavelength absorption targets. The custom-tailored supercell may be arranged with a plurality of other custom-tailored supercells into an acoustic panel.