Simulation and Identification of Organized Structures in Flows. Edited by J. N. SORENSEN, E. J. HOPFINGER & N. AUBRY. Kluwer, 1999. 515 pp. ISBN 0 7923 56039. NLG 395 or US$237 or £104.

Abstract

This book is the Proceedings of the IUTAM Symposium on ‘‘Simulation and Identification of Organised Structures in Flows,’’ held in Lyngby, Denmark, May 25‐29, 1997. The symposium was one of those specialized symposia in the field of mechanics that the International Union of Theoretical and Applied Mechanics (IUTAM) organizes every year. The IUTAM Symposia are normally reserved to invited participants, and usually provide the state-of-the-art assessment of a particular problem by leading professionals. This book is no exception. It presents a useful overview of organized structures in fluid mechanical applications. It covers a wider range of issues than did a previous Symposium on a similar topic held in October 1992 in Poitiers, France. Selected papers from that Symposium—‘‘Eddy Structure Identification in Free Turbulent Shear Flows’’—were published in a Proceedings edited by J. P. Bonnet and M. N. Glauser (1993). Information on organized structures in flows and their interactions with flow boundaries is of considerable hydraulic engineering importance. For instance, work underway at New Zealand’s National Institute of Water and Atmospheric Research (NIWA) on periphyton (attached aquatic microalgae) interactions with turbulence is revealing significant mechanisms of mass transfer in the near-bed region. Such mechanisms appear to influence periphyton growth and losses. ADV measurements of turbulence in the NIWA outdoor ecohydraulics flume (Fig. 1) show that the appearance of periphyton on a cobble bed does not change appreciably the velocity spectra above the cobble. However, its appearance reduces the total spectral energy and generates a wide spectral peak in the region below cobble tops. Most probably, this peak is formed by penetration of sweep events into that region, ‘‘filtered’’ by the periphyton tufts. Thus, organized structures may be the main mechanism responsible for the delivery of nutrients from the outer region to the biologically active near-bed layer.