The existence and crucial role played by large-scale, organized motions in turbulent flows are now recognized by industrial, applied and fundamental researchers alike. It has become increasingly evident that coherent structures influence mixing, noise, vibration, heat transfer, drag, etc... The accelera tion of the development of both experimental and computational programs devoted to this topic has been evident at several recent international meet ings. One of the first questions which experimentalists or numerical analysts are faced with is: how can these structures be separated from the background turbulence? This is a nontrivial task because the coherent structures are gen erally embedded in a random field and the technique used to determine when and where certain structures are passing, or their averaged characteristics (in the more probable or dominant role sense) is directly related to the definition of the coherent structure. Several methods or approaches are available and the choice of a particular one is generally dependent on the desired informa tion. This choice depends not only on the definition of the structure, but also on the experimental and numerical capabilities available to the researcher.

The existence and crucial role played by large-scale, organized motions in turbulent flows are now recognized by industrial, applied and fundamental researchers alike. It has become increasingly evident that coherent structures influence mixing, noise, vibration, heat transfer, drag, etc. This volume contains selected papers from the IUTAM symposium entitled Eddy Structure Identification in Free Turbulent Shear Flows' which was held in Poitiers, France, October 12--14, 1992. The purpose of the IUTAM symposium was to address some important questions, which are documented in this volume: What is the state of the art of structure identification? How do these approaches work? How do the results from different techniques compare with one another? What kind of information can be obtained from the various methods (e.g., instantaneous results, vorticity, averages, statistics, etc...)? What are the new directions in detection methods and, correspondingly, what are their implications for turbulent flow analysis and prediction methods? /LIST This book will contribute to the knowledge of coherent structure identification processes and will help guide future experimental, numerical and theoretical research in this area. Turbulence researchers will find this volume an invaluable reference."