The rear of a sectioned Rolls-Royce Turboméca Adour turbofan displayed at the Musée de l’Air in Paris, France. Air flow is from right to left.
The photo shows the mechanism responsible for varying the nozzle geometry, so it can be adapted to the flow rate and exhaust gas speed (most strikingly during afterburner use).
<a href="//commons.wikimedia.org/wiki/User:Ariadacapo" title="User:Ariadacapo">Olivier Cleynen</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>