Patent ID: 7600384

Claim:
A gas exhaust nozzle for a bypass turbomachine, the nozzle comprising an annular central body centered on a longitudinal axis of the nozzle, an annular primary cowl surrounding the central body coaxially so as to co-operate therewith to define a primary annular channel, and an annular secondary cowl surrounding the primary cowl coaxially so as to co-operate therewith to define a secondary annular channel coaxial with the primary channel, wherein the secondary cowl comprises a stationary portion and a movable portion extending the stationary portion longitudinally and capable of moving longitudinally upstream and downstream relative to the stationary portion and relative to the primary cowl so as to vary the exhaust section and/or the throat section of the nozzle, the stationary portion of the secondary cowl presenting a plurality of repetitive patterns circumferentially spaced apart and longitudinally extending its trailing edge, and the moving portion of the secondary cowl having in its outside surface a plurality of indentations of shapes complementary to the patterns of the stationary portion.