Primary nozzle with chevrons for bypass turboreactor engine of an aircraft and aircraft with such a nozzle

The pipe has an internal skin (2) inside which circulates a primary air flow (FP) and which comprises chevrons (4), at an external end. An external skin (3) partially surrounds the internal skin and along which flows a secondary air flow (FS). The external skin is movable along the internal skin. A sliding device (5) is placed between the internal skin and the external skin. An independent claim is also included for an aircraft with turbofan engine.