Variable area nozzle assembly for an aircraft propulsion system

A variable area nozzle assembly for an aircraft propulsion system, the variable area nozzle assembly comprising:

• a center plug disposed along an axis, the center plug includes a plug body and a seal, and the seal extends circumferentially about the plug body;
• an outer nozzle extending circumferentially about the axis and the center plug;
• and
• an inner nozzle extending circumferentially about the axis and the center plug, the inner nozzle is disposed radially between the center plug and the outer nozzle, the inner nozzle includes an inner nozzle body, the inner nozzle body forms a secondary duct for a secondary gas stream radially between the inner nozzle body and the center plug, the inner nozzle body includes an outer radial portion, an inner converging portion, and an inner radial portion, the outer radial portion and the inner converging portion form a primary duct for a primary gas stream radially between the inner nozzle body and the outer nozzle, the inner converging portion extends between and to the outer radial portion and the inner radial portion, the inner radial portion is radially spaced inward of the outer radial portion, the inner radial portion includes an outer radial surface and an inner radial surface, the outer radial surface faces the inner converging portion, the inner radial surface faces the center plug and contacts the seal, the inner radial surface forms a nozzle outlet for the secondary gas stream downstream of the seal between the inner radial surface and the center plug, the inner radial portion forms a plurality of apertures extending between and to the outer radial surface and the inner radial surface, and the plurality of apertures are disposed at and in fluid communication with the secondary duct.

A propulsion system for an aircraft, the propulsion system comprising:

• a gas turbine engine disposed along an axial centerline, and the gas turbine engine forms a core flow path;
• a nacelle extending circumferentially about and housing the gas turbine engine, and the nacelle forms a bypass flow path radially between the nacelle and the gas turbine engine;
• and
• a variable area nozzle assembly comprising:
• a fixed center plug disposed along the axial centerline, the fixed center plug includes a plug body and a seal, and the seal extends circumferentially about the plug body;
• a fixed outer nozzle extending circumferentially about the axial centerline and the fixed center plug, the fixed outer nozzle includes a distal end;
• and
• an inner nozzle extending circumferentially about the axial centerline and the fixed center plug, the inner nozzle is disposed radially between the fixed center plug and the fixed outer nozzle, the inner nozzle includes an inner nozzle body, the inner nozzle body forms a primary duct radially between the inner nozzle and the fixed outer nozzle, the primary duct is configured to receive a core combustion gas flow from the gas turbine engine along the core flow path, the primary duct includes an exit plane at the distal end, the inner nozzle body forms a secondary duct, the secondary duct is disposed radially between the inner nozzle body and the fixed center plug upstream of the seal, the secondary duct is configured to receive at least a portion of a bypass air flow along the bypass flow path, the inner nozzle body forms a plurality of apertures, and the inner nozzle body is axially translatable between and to a first axial position and a second axial position relative to the axial centerline,
• in the first axial position, the primary duct has a first cross-sectional area at the exit plane and the plurality of apertures are isolated from a nozzle outlet of the secondary duct by the seal, and
• in the second axial position, the primary duct has a second cross-sectional area at the exit plane, the second cross-sectional area is less than the first cross-sectional area, and the plurality of apertures are connected in fluid communication with the nozzle outlet to direct the bypass air flow from the secondary duct and into the nozzle outlet.