Making Turbofan Engines More Energy Efficient

Abstract

A review of transport aircraft gas turbine engine development and evolution during the past two decades is presented in terms of energy consumption. The interaction and effects of cycle pressure ratio, firing temperature, bypass ratio, and component efficiencies on installed fuel consumption are reviewed. The possibilities for further substantial improvement in energy efficiency with improved operating economics and with improved environmental characteristics are identified and evaluated. Parametric data are presented showing trade-offs in the areas of efficiency and economics. Environmental considerations are also discussed. The balance of these factors in a cost-effective advanced turbofan is discussed. In conclusion, projections are made for the capability of an advanced turbofan engine compared with the goals established by NASA for their Energy Efficient Engine Program. The characteristics of this more efficient, cost-effective power plant, that can be operational in the late 1980’s, are shown in relationship to current turbofan engines.