高经济性静音中航程民机设计方法讨论

 人们已愈来愈重视工业产品对环境的影响。人们直接感受民机对环境的影响首先是机场周边的噪声。静音飞机预案的研究目标是设计一种飞机，在机场周边听不见其响声，且油耗和排污指标优于现有的和正在设计的其他飞机。通过介绍SAX（Silent Aircraft eXperiment）三代概念机的研究进程，讨论了静音飞机设计的方法和使用的关键技术，包括具有一定准确度的快速翼身融合体准三维设计方法；具有最佳中央体外形的融合体气动外形设计；可平滑下弯的外翼前缘和后缘刷；分布、埋入式多风扇可吞吸边界层的发动机组；喷口截面可变的推力矢量喷管；先进的隔音衬管；整流的起落架等。最终的概念机SAX-40实现了在机场周边的最大噪声计算值为61 dBA，接近于稠密居民区的背景噪声，且使机场周边的人们不易感觉到飞机的起飞/进场。其油耗经济性亦达到了124座 哩/加仑的优异指标。

Discussion of Design Methods for Silent and Fuel Efficient Medium Range Civil Transport

People are more and more concerned about the influence of industrial products on environment.Aircraft noise around airports is the complained environmental impact of civil aviation.The goal of silent aircraft initiative is to design a conceptual aircraft,which is inaudible outside the airport perimeter and also in fuel efficiency and emission control superior to present and future conventional aircraft.By introducing three generations of conceptual silent aircraft experiment(SAX),this paper discussed the design method and enabling technology,including a quasi-3D design method with fast turnaround time and adequate fidelity;aerodynamic design of the blended wing body by optimally shaping its centerbody;deployed drooped leading edge and trailing edge brushes of the outer wing;distributed multi-fan embedded turbofan with boundary layer ingestion;thrust vectoring nozzle with variable exit area;advanced acoustic linears;and faired undercarriage,etc.Finally,the resulting conceptual aircraft design,SAX-40,yields a calculated noise level of 61 dBA at the airport perimeter,which is close to the background noise in a well populated area and imperceptible to the human ear on takeoff and landing.SAX-40 also has the potential for a reduced fuel burn of 124 passenger-miles per gallon.