Published online by Cambridge University Press: 20 April 2006
The publication of this 25th Anniversary Issue of the Journal of Fluid Nechanics is a fitting moment to consider some of the new ways in which fuid flow has been controlled and exploited and the relationship between these practical developments and the kind of scientific studies reported in this journal. From Leonard0 to Lanchester to Lighthill the application of the understanding of fluid motions to the study and practice of flight, whether man-made or natural, has gone hand-in-hand with the scientific development of the subject. But, although from the earliest times fluid motion has been controlled and exploited for industrial and environmental purposes, the connection between these applications of fluid flow and its scientific study is nothing like as direct or as widespread, perhaps because the costs and dangers of failure in these fields are somewhat less. It is particularly appropriate to discuss these aspects of fluid flow, because one of J F M's most noticeable features has been the publication of papers on new ideas which already have had or may have some interesting non-aeronautical applications.