涵道比对大型客机经济性和环保性的影响

为了综合评估配装发动机的涵道比对客机的经济性和环保性的影响，建立了一套包括动力、几何、气动、质量、性能、经济性、噪声、排放分析模型的多学科分析流程.以典型宽体客机为应用算例，分析了不同涵道比（8~14）发动机对宽体客机经济性和环保指标的影响.综合分析结果表明:增大发动机涵道比有利于降低客机噪声和起降循环氮氧化合物污染物的排放；而发动机涵道比为11左右时，客机的现金使用成本最低，航线氮氧化合物污染物排放量最少. 

Effects of bypass ratio on the cost and environmental performance of large civil aircraft

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.