An experimental investigation into the wall jets created by a single inclined, twin inclined and a four inclined jet impingement arrangement is described. Wall jet velocity profiles were recorded at various azimuthal and radial locations for a range of nozzle heights at jet pressures representative of current V/Stol technology. Use was made of wall jet properties established for a normal jet impingement to provide a means of comparing the attributes of the various configurations. Non-splayed twin inclined impinging jets generate symmetry plane reinforcement and weakening in regions remote from the interaction. Splayed jet geometries show significant height effects on ground plane flow development. The four-jet configuration also demonstrates velocity reinforcement at the lines of wall jet interaction, together with a weakening of the flows remote from the interaction planes. Reinforcement velocities for the four-jet case are significantly lower than those expected from the constituent twin-jet flows.

A model of the viscous flow past a flexible sail section operating near the ideal incidence is described. Viscous effects are calculated via weak viscous-inviscid interaction of a panel method and an integral boundary layer method, and a new model for the leading edge separation bubble is introduced. The flexible section is allowed to deform in response to the pressure and shear stresses acting on it. Results are presented for the effect of incidence, excess length and Reynolds number on the development of the boundary layers on each side of the section and the consequences for the lift and drag of the section are described. The numerical model is compared with experimental results, giving in general good agreement and shedding light on the physics of the viscous flow past flexible membranes.

This paper describes a concept study of the Spacecab Demonstrator project, which is a small two seat aeroplane capable of routine “zoom-climbs” to space altitude. It is powered by a jet engine and a rocket motor. It would be the first sub-orbital spaceplane since the X-15 of thirty years ago. The study shows that Spacecab Demonstrator should be a simple robust development using existing technology. It would be used as a spaceplane technology testbed, as a reusable sounding rocket for space research and for specialised commercial applications. More importantly, it would serve as a pathfinder for the Spacecab orbital spaceplane, which is designed to be the first fully reusable launch vehicle. Spacecab uses existing engines and proven materials and is designed with provision for certification to airliner standards. Enlarged and mature developments of Spacecab would reduce the cost of sending people into space by three orders of magnitude compared with the cost today, and this could probably be achieved in about 15 years.

The results of a computational fluid dynamics analysis of three prominent World War II fighter aircraft, the Supermarine Spitfire, North American P-51 Mustang and Focke Wulf Fwl90 are presented. The goal of this analysis was to learn the strengths and weaknesses inherent in the aerodynamics of these aircraft. Design features covered include comparisons of the wing designs and calculated total wetted areas along with a look at specific details of the aerodynamics of each aircraft. This information, while historical, still has relevance in today's world of aircraft design.

Unlike commercial air transport and military aircraft, the high performance glider was developed as an end in itself so that individual pilots could achieve extended flights using only energy present in the air. From modest beginnings in the first two decades of this century the best gliders available today are able to fly 60 miles from a height of about 6000 ft in no wind and without upcurrents. Using thermals and other available lift in the air these gliders are capable of flying a distance of 1000 miles in a day. The realisation of such performance efficient gliders was possible because the design problems attracted top quality aerodynamicists. Germany led, and still leads, because German universities saw, in glider development, a fine training ground for young aeronautical engineers — initially encouraged, of course, by the Versailles Treaty which forbade the manufacture of powered aircraft at the end of WW1. Now superb gliders exist but because of their cost, complexity and size they can be afforded and/or flown by only a relatively small number of pilots. This paper follows the historical development of gliders, the arrival of hang gliders and paragliders and considers the way forward for motorless flight.