What is the function of the exhaust nozzle in a jet engine?

The exhaust nozzle accelerates the exhaust gases to produce thrust by converting pressure energy to kinetic energy. Nozzle types include: Convergent nozzles for subsonic exhaust (most commercial engines), Convergent-divergent (C-D) nozzles for supersonic exhaust (military, rockets), and Variable-area nozzles for optimizing performance across operating conditions. The nozzle pressure ratio determines if flow is choked (Mach 1 at throat) or supersonic. Proper nozzle design maximizes thrust coefficient while meeting noise, weight, and cooling requirements. Thrust reversers and mixer/ejector systems are integrated into the nozzle assembly.