Method and apparatus for variable exhaust nozzle exit area

A nozzle effective exit area control system is created with a convergent - divergent nozzle (10) with a divergent portion (14) of the nozzle having a wall at a predetermined angle of at least 12° from the freestream direction. Disturbance generators (24,26) are located substantially symmetrically oppositely on the wall to induce flow separation from the wall with the predetermined wall angle inducing flow separation to extend upstream from each disturbance generator (24,26) substantially to a throat of the nozzle pressurizing the wall and reducing the effective area of the jet flow at the nozzle exit.