Engine exhaust nozzle with acoustic attenuation

An assembly for a gas turbine engine, comprising:

• an exhaust nozzle extending circumferentially about an axial centerline, the exhaust nozzle extending axially along the axial centerline to a trailing edge, the exhaust nozzle extending radially between an exterior inner surface and an exterior outer surface, the exterior inner surface configured to form an outer peripheral boundary of a core flowpath of the gas turbine engine through the exhaust nozzle, and the exterior outer surface configured to form an inner peripheral boundary for bypass air directed out of a bypass flowpath of the gas turbine engine outside of the exhaust nozzle;
• the exhaust nozzle including an inner skin, an outer skin, a first bulkhead, a second bulkhead, a first cavity and a second cavity;
• the inner skin forming the exterior inner surface and comprising a plurality of perforations;
• the outer skin connected to the inner skin at an intersection at the trailing edge;
• the first bulkhead extending radially between and connected to the inner skin and the outer skin, the first bulkhead disposed at an upstream end of the outer skin;
• the second bulkhead extending radially between and connected to the inner skin and the outer skin;
• the first cavity disposed radially between and formed by the inner skin and the outer skin, the first cavity extending axially within the exhaust nozzle uninterrupted from the first bulkhead to the second bulkhead, and the first cavity fluidly coupled with the plurality of perforations;
• the second cavity disposed radially between and formed by the inner skin and the outer skin, and the second cavity extending axially within the exhaust nozzle uninterrupted from the second bulkhead to the intersection at the trailing edge;
• and
• the exhaust nozzle further including a plurality of baffles, each of the plurality of baffles extending radially between the inner skin and the outer skin, each of the plurality of baffles extending axially between the first bulkhead and the second bulkhead, and the plurality of baffles including a first baffle and a second baffle, and the first cavity extending circumferentially within the exhaust nozzle between the first baffle and the second baffle.