Variable-geometry convergent-divergent exhaust nozzle

A variable-geometry convergent-divergent exhaust nozzle for a gas turbine engine, the variable-geometry convergent-divergent exhaust nozzle comprising:

• an exhaust duct configured to receive an exhaust flow of gas from a combustor of the gas turbine engine;
• a first flap assembly comprising a first proximal flap and a first distal flap;
• and
• a second flap assembly comprising a second proximal flap and a second distal flap,
• wherein the first proximal flap is rotatably coupled to the exhaust duct and comprises a first entry surface that in part defines a nozzle passageway, the nozzle passageway being configured to convey the exhaust flow of gas to an exterior of the gas turbine engine,
• wherein the second proximal flap is rotatably coupled to the exhaust duct and comprises a second entry surface that in part defines the nozzle passageway,
• wherein the first distal flap is rotatably coupled to the first proximal flap,
• wherein the second distal flap is rotatably coupled to the second proximal flap,
• wherein the first distal flap comprises a first converging surface and a first diverging surface angled with respect to the first converging surface,
• wherein the second distal flap comprises a second converging surface and a second diverging surface angled with respect to the second converging surface,
• wherein the first converging surface and the second converging surface define at least in part a convergent portion of the nozzle passageway,
• wherein the first diverging surface and the second diverging surface define at least in part a divergent portion of the nozzle passageway.