Future large aircraft design — the delta with suction

Abstract

AbstractSince the 1970s, large passenger aircraft design has evolved by modest, but commercially significant, incremental change following the underwing pod concept pioneered by the Boeing 707. In the 21st century, the market is likely to require greater passenger capacity to deal with air-side congestion and higher performance and operational efficiency to justify investment and conserve finite fossil fuel resources. Public opinion will require far greater emphasis on control of noise and engine exhaust pollution. There is likely to be much increased emphasis on pollution in the upper-atmosphere and its environmental impact. In such a situation, it is questionable whether the evolutionary design route can produce the necessary advances and this must stimulate the search for radical design alternatives.A revolutionary approach, involving the delta planform combined with wing laminar flow control and its impact on overall design, is given a preliminary study in this paper. This has been carried out by assuming that major improvements in drag can be obtained by extensive laminarisation. Using non-dimensional methods, the resulting broad interactive impacts on airframe and engine design and performance are derived. The effect of assuming varying quantities of low-energy air sucked from the foot of the boundary layer is studied and suction-system performance examined.In addition to the large potential improvements in range, a strong relationship between lower drag, lower cruising altitude and lower cruise engine size is identified. In the study, several factors emerge which may combine to drive large aircraft design towards low aspect ratio and the integrated delta wing planform. This paper is intended as a stimulus and a basis for further study and research.