Introductory Remarks

Abstract

The history of research in turbulent compressible flows is somewhat checkered, in that shifts in national and international priorities have had a large impact on the continuity of effort. The high level of activity that lasted from the end of the Second World War to about 1965 was largely driven by the wish to fly at supersonic speeds, and to solve the problems associated with re-entry. Once these problems were “solved” (in an engineering sense), the funding dried up, and further efforts became severely restricted. The recent upsurge in activity has been mainly driven by a new set of priorities such as the projected need for a low-cost supersonic transport aircraft, and the desire to fly at hypersonic speeds. However, much of the fundamental knowledge required to attain hypersonic flight is not yet available, and “generic” hypersonic research is now receiving considerable attention. In a similar way, the next generation of supersonic transports will need to be highly fuel efficient, cause minimum ozone depletion and minimum noise levels. The understanding of compressibility effects on turbulence will undoubtedly have a significant impact on the development of engineering solutions to these problems.