Variable-Geometry Exhaust Nozzles and Their Effects on Airplane Performance

The development of exhaust nozzles and their application in operational military aircraft are discussed. Prime consideration is given to installation factors such as engine bay and nozzle cooling, inlet-engine flow matching, and aerodynamic effects on external afterbody drag. Examples of various operational exhaust systems are given which show how the aircraft-exhaust nozzle characteristics are integrated to achieve maximum system compatibility and performance. Results from one flight test program are presented which show how an aircraft-exhaust nozzle system was integrated to achieve maximum installed performance.