REQUIREMENTS FOR LONG RANGE -LONG ENDURANCE AIRCRAFT

Propulsion system requirements of long range, long endurance aircraft are described with emphasis on turbofan engines. The factors influencing the optimum design bypass ratio of a turbofan engine are discussed, and some effects of laminar flow control and cargo space requirements upon optimum turbofan engine design are shown. A parametric study of airplane performance is used to compare a series of industry study engines as a means of showing the relationship between airplane design and engine design. Clean airplane designs require significantly higher bypass ratios for maximum range and endurance.