In order to assess the effects of bypass ratio on the cost and environmental performance of the civil aircraft with consideration of engine installation

a multidisciplinary analysis procedure was established

in which propulsion

geometry

aerodynamics

mass

mission performance

cost

noise and emissions analysis module were integrated. A typical wide body civil aircraft was used to illustrate the procedure

in which the cost and enviromental performance of wide body aircraft was analyzed with different engine bypass ratios ranging from 8 to 14. The results show that the civil aircraft with the highest bypass ratio engine achieves the lowest noise and landing-takeoff NOx emissions. However

the civil aircraft with the engine of moderate bypass ratio (around 11) has the lowest cash operating cost and flight NOx emissions.