An experimental investigation into the wall jetscreated by a single inclined, twin inclined and afour inclined jet impingement arrangement isdescribed. Wall jet velocity profiles were recordedat various azimuthal and radial locations for arange of nozzle heights at jet pressuresrepresentative of current V/Stol technology. Use wasmade of wall jet properties established for a normaljet impingement to provide a means of comparing theattributes of the various configurations.Non-splayed twin inclined impinging jets generatesymmetry plane reinforcement and weakening inregions remote from the interaction. Splayed jetgeometries show significant height effects on groundplane flow development. The four-jet configurationalso demonstrates velocity reinforcement at thelines of wall jet interaction, together with aweakening of the flows remote from the interactionplanes. Reinforcement velocities for the four-jetcase are significantly lower than those expectedfrom the constituent twin-jet flows.

A model of the viscous flow past a flexible sailsection operating near the ideal incidence isdescribed. Viscous effects are calculated via weakviscous-inviscid interaction of a panel method andan integral boundary layer method, and a new modelfor the leading edge separation bubble isintroduced. The flexible section is allowed todeform in response to the pressure and shearstresses acting on it. Results are presented for theeffect of incidence, excess length and Reynoldsnumber on the development of the boundary layers oneach side of the section and the consequences forthe lift and drag of the section are described. Thenumerical model is compared with experimentalresults, giving in general good agreement andshedding light on the physics of the viscous flowpast flexible membranes.

This paper describes a concept study of the SpacecabDemonstrator project, which is a small two seataeroplane capable of routine “zoom-climbs” to spacealtitude. It is powered by a jet engine and a rocketmotor. It would be the first sub-orbital spaceplanesince the X-15 of thirty years ago. The study showsthat Spacecab Demonstrator should be a simple robustdevelopment using existing technology. It would beused as a spaceplane technology testbed, as areusable sounding rocket for space research and forspecialised commercial applications. Moreimportantly, it would serve as a pathfinder for theSpacecab orbital spaceplane, which is designed to bethe first fully reusable launch vehicle. Spacecabuses existing engines and proven materials and isdesigned with provision for certification toairliner standards. Enlarged and mature developmentsof Spacecab would reduce the cost of sending peopleinto space by three orders of magnitude comparedwith the cost today, and this could probably beachieved in about 15 years.

The results of a computational fluid dynamics analysisof three prominent World War II fighter aircraft,the Supermarine Spitfire, North American P-51Mustang and Focke Wulf Fwl90 are presented. The goalof this analysis was to learn the strengths andweaknesses inherent in the aerodynamics of theseaircraft. Design features covered includecomparisons of the wing designs and calculated totalwetted areas along with a look at specific detailsof the aerodynamics of each aircraft. Thisinformation, while historical, still has relevancein today's world of aircraft design.

Unlike commercial air transport and military aircraft,the high performance glider was developed as an endin itself so that individual pilots could achieveextended flights using only energy present in theair. From modest beginnings in the first two decadesof this century the best gliders available today areable to fly 60 miles from a height of about 6000 ftin no wind and without upcurrents. Using thermalsand other available lift in the air these glidersare capable of flying a distance of 1000 miles in aday. The realisation of such performance efficientgliders was possible because the design problemsattracted top quality aerodynamicists. Germany led,and still leads, because German universities saw, inglider development, a fine training ground for youngaeronautical engineers — initially encouraged, ofcourse, by the Versailles Treaty which forbade themanufacture 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/orflown by only a relatively small number of pilots.This paper follows the historical development ofgliders, the arrival of hang gliders and paraglidersand considers the way forward for motorlessflight.