An acoustic absorption structure comprising a plurality of resonators. Each resonator comprises a first chamber which has a first mouthpiece delimited by an edge pressed against an inner surface of a porous zone of a skin so that the first chamber and the skin delimit a first cavity, a second chamber, in which is positioned the first chamber, which delimits, with the first chamber, a second cavity, at least one acoustic orifice passing through the first chamber, at least one drainage orifice passing through the first chamber and at least one drainage hole passing the second chamber, each drainage orifice and each drainage hole being configured to limit an accumulation of fluid in the resonator. Also, an aircraft propulsive assembly or an aircraft comprising the acoustic absorption structure are provided.

Certain aspects of the present disclosure provide a nacelle for an engine, including a plurality of acoustic fairing assemblies disposed within an aft fan duct of the nacelle, wherein each acoustic fairing assembly of the plurality of acoustic fairing assemblies comprises: a fairing body comprising a plurality of acoustic cells; and a fairing face sheet comprising a plurality of perforations and configured to be attached to the fairing body.

Certain aspects of the present disclosure provide a nacelle for an engine, including a plurality of acoustic fairing assemblies disposed within an aft fan duct of the nacelle, wherein each acoustic fairing assembly of the plurality of acoustic fairing assemblies comprises: a fairing body comprising a plurality of acoustic cells; and a fairing face sheet comprising a plurality of perforations and configured to be attached to the fairing body.

A sound attenuating cell includes a first sound attenuating cavity defined between a first sidewall and a second sidewall. The first sidewall is opposite the second sidewall. The first sidewall includes a first undulating surface and the second sidewall includes a second undulating surface. A deflector is coupled to the first undulating surface. The deflector extends from the first undulating surface toward the second undulating surface. The first undulating surface is axially offset from the second undulating surface to define a tortuous path between the first sidewall and the second sidewall. The first sound attenuating cavity has a first end and a second end. The first end is opposite the second end, and an inlet and an outlet of the first sound attenuating cavity is defined at the first end. The sound attenuating cell includes a second sound attenuating cavity nested within the first sound attenuating cavity.

A sound attenuating cell includes a first sound attenuating cavity defined between a first sidewall and a second sidewall. The first sidewall is opposite the second sidewall. The first sidewall includes a first undulating surface and the second sidewall includes a second undulating surface. A deflector is coupled to the first undulating surface. The deflector extends from the first undulating surface toward the second undulating surface. The first undulating surface is axially offset from the second undulating surface to define a tortuous path between the first sidewall and the second sidewall. The first sound attenuating cavity has a first end and a second end. The first end is opposite the second end, and an inlet and an outlet of the first sound attenuating cavity is defined at the first end. The sound attenuating cell includes a second sound attenuating cavity nested within the first sound attenuating cavity.

A thermal barrier coating disposed on a substrate comprising a plurality of surface features formed on the substrate proximate an inner side of the substrate, each of the plurality of surface features comprising a metallic column having a top with rounded edges; a dense layer disposed in a valley located between each of the plurality of surface features, and the dense layer disposed on the top and covering the rounded edges; a thermally insulating topcoat disposed over the plurality of surface features.

A thermal barrier coating disposed on a substrate comprising a plurality of surface features formed on the substrate proximate an inner side of the substrate, each of the plurality of surface features comprising a metallic column having a top with rounded edges; a dense layer disposed in a valley located between each of the plurality of surface features, and the dense layer disposed on the top and covering the rounded edges; a thermally insulating topcoat disposed over the plurality of surface features.

A system and method that uses one or more jet engines to remove unmanned aircraft from restricted airspace. Generally, the force created by a jet engine can be used to remove drones or other unwanted objects from the restricted airspace. Once the system determines the presence of an unauthorized aircraft or object within the restricted airspace, the jet engine(s) can be activated and used to pull the drone or flying object towards the jet engine though the force created by the intake of the jet engine(s), or to expel the drone or object from the restricted area through the force created by the exhaust of the jet engine(s).

A system and method that uses one or more jet engines to remove unmanned aircraft from restricted airspace. Generally, the force created by a jet engine can be used to remove drones or other unwanted objects from the restricted airspace. Once the system determines the presence of an unauthorized aircraft or object within the restricted airspace, the jet engine(s) can be activated and used to pull the drone or flying object towards the jet engine though the force created by the intake of the jet engine(s), or to expel the drone or object from the restricted area through the force created by the exhaust of the jet engine(s).

An acoustic attenuator comprises a first attenuation unit, a second attenuation unit, a welded section, and a communication part. A first acoustic damper is provided on an outer surface of a first acoustic liner, which faces toward a side opposite from an object, to form a first damper space that communicates with an internal space of the object. The second attenuation unit is attached to an outer surface of the object. The welded section is provided at least between the first acoustic damper and a second acoustic damper. The welded section secures the second attenuation unit to the first acoustic liner. The communication part is disposed in a position farther from an outer surface of the object than the welded section, allowing communication between the first damper space and a second damper space.