Two-dimensional nozzle

A two-dimensional exhaust nozzle construction for aircraft powered by a turbine type power plant receiving the fluid working medium exhausting in the ambient, a collapsible plug centrally mounted in said two-dimensional nozzle, at least one flap adjacent said nozzle and in spaced relationship defining a wall of said two-dimensional nozzle, said flap being a rigid member and said flap and said plug defining a passageway for conducting the fluid in said two-dimensional nozzle exhausting to ambient, said flap and said plug defining a throat angle and (throat are in the passageway, said flap movable in concomitant radial and axial directions to define a first geometry for optimizing the exhaust stream in a subsonic condition by making the throat angle substantially perpendicular at the exit of said flap relative to the plug surface and a second geometry for optimizing the exhaust stream in a supersonic condition by moving the throat within the flap and having its angle greater than the perpendicular relative to the plug surface, and means for scheduling the throat angle and throat area independent of each other.