Turbulence at high Reynolds number is interesting from a fundamental point of view, in that most theories of turbulence make very specific predictions regarding the behaviour of turbulence with increasing Reynolds number. From a more practical point of view, many very important applications of high Reynolds number flow pertain to the motion of large vehicles, atmospheric and other geophysical flows where the understanding of climate changes and the prediction of destructive weather effects hinges to a significant extent on our appreciation of high-Reynolds number turbulence behaviour. This volume contains selected papers from the IUTAM Symposium entitled Reynolds Number Scaling in Turbulent Flow, held on September 11-13, 2002 in Princeton, NJ, USA. The purpose of the symposium was to bring together many of the world’s experts in this area to appraise the new experimental results, discuss new scaling laws and turbulence models, and to enhance our mutual understanding of turbulence. This book should contribute to the knowledge of turbulence, and help guide future experimental, numerical and theoretical research in this area.