涵道比对运输机发动机性能和经济性影响分析

Analysis of effect of bypass radio on the performance and economy of transport aeroengine

基于现有核心机研究了不同涵道比发动机总体性能方案。随着涵道比增加,发动机耗油率减小,起飞推力增加,同时发动机重量和尺寸增加,在同一涵道比条件下,存在最佳风扇外涵压比使发动机耗油率最小。研究了不同涵道比发动机对飞机起飞重量的影响。结果表明:存在最佳涵道比使得飞机的起飞重量最轻,且航程越长,最佳涵道比越大。分析了不同涵道比发动机对飞机经济性的影响,同样也存在最佳涵道比,使飞机的成本最低,该最佳涵道比的大小受到航程、燃油价格和飞机使用频率的影响。

The general aeroengine performance schemes with different bypass ratios （BPR） are investigated based on the core engine. With the BPR increasing, specified fuel consume （SFC） is reduced, takeoff thrust enhanced, and the total weight and the size of aeroengine are increased. On the condition of one BPR, there is an optimal BPR which minimizes the SFC. The effect of aeroengine with different BPRs on the takeoff weight of aircraft has been studied. The result shows that there is an optimal BPR which minimizes the take- off weight;moreover, the longer the flight distance gets, the bigger the optimal BPR is. The effect of aero- engine with different BPR on the flight economy has also been studied. There is an optimal BPR which minimizes the flight cost. The optimal BPR is affected by flight distance, fuel price and the frequency of mission.