Since 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.

An implicit cell-vertex upwind method is presented for the solution of the two-dimensional Euler equations for supersonic flows. It is based on the two-point difference scheme introduced by S.F. Wornom, but contains many significant developments. Particular attention is given to the implementation of boundary conditions, to ensure that no “numerical” boundary conditions are required, and “image” cells are avoided, making the scheme ideal for use in conjunction with a multiblock approach. Examples are given for quasi-one-dimensional nozzle flows, and in two dimensions, oblique shock reflection, a shock interaction problem, and a supersonic intake problem. The accuracy and efficiency of the scheme is demonstrated, along with its ease of use.

Convective heat transfer data is frequently obtained from transient surface temperature measurements. Thin film resistance gauges, thermocouples, and thermochromic liquid crystals, are used in various situations to measure the surface temperature history. By assuming that uniform semi-infinite flat plate conditions apply, it is possible to express the instantaneous surface heat flux as an analytical function of the transient surface temperature(1). Various approaches can be used to account for the presence of multi-layered substrates and finite thickness substrate effects (Schultz and Jones(1); Doorly and Oldfield(2); Guo et al(3)), however, the effects of surface curvature are usually neglected.

What is of central importance in progressing new materials through from development to use is not technology but the creative efficiency of the team. What results is technology, both a competence and a confidence in handling the new material that makes the clarity of the demonstration of its potential a delight. It requires a holistic approach. Clear concepts require functionally direct embodiment, and equally expressive robust detailing. No amount of additional detail will retrieve a bad concept. Growing a team that has enough insight to tell the difference and the courage not to settle for less than the best is the challenge.

The flight test phase of the Nasa-Army UH-60A Airloads Program was completed in February 1994. The objective of the project was to measure the airloads in flight on an UH-60A Black Hawk using 221 blade pressure transducers installed in nine radial arrays. In addition, 21 transducers were installed along the blade leading edge to better identify blade-vortex interaction phenomena. This paper briefly describes the program's background and history, instrumentation, and data acquisition. Airloads data are presented for two test conditions with different levels of complexity: steady, level flight and a diving turn. These flight data provide useful information of relatively simple and complex nonlinear flow for the validation of theoretical analyses. Evidence of shock waves, reverse flow, dynamic stall and blade vortex interactions are presented.