Trends in Military Aircraft Propulsion

Abstract

The major factors determining the choice of engine cycle for a combat aircraft are the requirements of the design mission and those of aircraft speed and agility. The requirement for jet-borne flight in short take-off vertical landing (STOVL) aircraft imposes further demands on cycle and configuration. The changing nature of combat aircraft requirements is the reason for changes in engine design. Specific thrust is shown to be the major parameter defining engine suitability for a particular role. An examination of mixed turbofan characteristics shows that specific thrust is also the key to understanding the relationships between engine characteristics. The future development of combat engines is discussed, in particular the implications of stoichiometric limits on cycle temperatures and the benefits of variable cycle engines are examined. Recent work on advanced STOVL (ASTOVL) aircraft is reviewed and aircraft/engine concepts designed to meet the requirements of the role are assessed. Experience shows that the technology for these advanced engines must be fully demonstrated before production to minimize the risks and costs of the development programme.

Optimization of gas turbines for sustainable turbojet propulsion

“…Other research works studied the effects compressor pressure ratio on thrust and other performance parameters [13]. In military applications there were special studies on the factors which determine the proper choice of engine cycle for a combat aircraft to suit the requirements of the designed mission [14]. Some researchers used energy and exergy analyses with a turbojet engine over flight altitudes ranging from sea level to 15000 m to determine the relative effects of operating variables [15].…”

Method for Propulsion Technology Impact Evaluation via Thermodynamic Work Potential

“…This approach can be very accurate and effective, and has been a standard method for evaluation of technology impact for many years. Czysz et al 2 and Denning 3 give interesting examples of this approach to investigate potential payoffs of variable geometry engines in fighter aircraft.…”