Dual-mode plug nozzle

A gas turbine engine for a supersonic aircraft, the gas turbine engine having a nozzle for directing exhaust flow to atmosphere, the nozzle comprising:

• a centerbody extending along a longitudinal axis and including, sequentially, a sloping forward section, a maximum diameter section, and an aft section;
• an annular inner shroud having an outer surface and an inner surface, the inner surface including a middle section of decreased diameter relative to the remainder of the inner surface, the annular inner shroud terminating at an aft edge and being selectively moveable along the longitudinal axis between forward and aft positions relative to the centerbody;
• an annular outer shroud having an inner surface and an outer surface, the annular outer shroud being selectively movable between forward and aft positions relative to the centerbody;
• and
• actuators operable to independently translate the annular inner shroud and the annular outer shroud between the respective forward and aft positions of the annular inner shroud and the annular outer shroud,
• wherein, when the annular inner shroud is in the forward position, the aft edge of the annular inner shroud is forward of the maximum diameter section of the centerbody, such that a throat area of the nozzle is formed between the aft edge of the annular inner shroud and the sloping forward section of the centerbody, and
• wherein, when the annular outer shroud is in the forward position, an aft edge of the annular outer shroud is forward of the maximum diameter section of the centerbody, such that an exit area of the nozzle is formed between the aft edge of the annular outer shroud and the centerbody.

A gas turbine engine for a supersonic aircraft, the gas turbine engine comprising:

• a compressor, a combustor, and a turbine disposed in series flow sequence along a longitudinal axis;
• a nozzle disposed downstream of the turbine, including:
• a centerbody extending along the longitudinal axis and including, sequentially, a sloping forward section, a maximum diameter section, and an aft section;
• an annular inner shroud having an outer surface and an inner surface, the inner surface including a middle section of decreased diameter relative to the remainder of the inner surface, the annular inner shroud terminating at an aft edge and being selectively moveable along the longitudinal axis between forward and aft positions relative to the centerbody;
• an annular outer shroud having an inner surface and an outer surface, the annular outer shroud being selectively movable between forward and aft positions relative to the centerbody;
• and
• actuators operable to independently translate the annular inner shroud and the annular outer shroud parallel to the longitudinal axis,
• wherein, when the annular inner shroud is in the forward position, the aft edge of the annular inner shroud is forward of the maximum diameter section of the centerbody, such that a throat area of the nozzle is formed between the aft edge of the annular inner shroud and the sloping forward section of the centerbody, and
• wherein, when the annular outer shroud is in the forward position, an aft edge of the annular outer shroud is forward of the maximum diameter section of the centerbody, such that an exit area of the nozzle is formed between the aft edge of the annular outer shroud and the centerbody.