Design Study for a Fuel Efficient Turbofan Engine

Abstract

An engine design study is presented in which the target is a 15 percent reduction in installed specific fuel consumption over the large engines currently in service while still meeting anticipated noise and emissions regulations. The fuel saving is achieved with a low specific thrust (bypass ratio 10) and a high overall cycle pressure ratio (42 at cruise). A three-shaft design is proposed, employing highly loaded components in order to reduce the number of turbomachinery stages and hence keep down cost and weight. It is argued that this approach is the one most compatible with projected technological advances. The engine configuration is given and the key features explained, highlighting areas where further research would be of particular advantage. Finally, the predicted engine performance is given, together with an estimate of the savings in direct operating cost.