Waves: easy to appreciate

Turbulent flows are ubiquitous and of far-ranging practical significance in many facets of engineering and common experience. Like the waviness of the seas, they are easy to appreciate but more difficult to define and rationalise. The subject may be described, taught and practised at a range of levels from simple phenomenology to advanced numerical simulation.

This book seeks to provide "a solid grounding" and may be best used by advanced course students - a group for which it was initially intended. A more advanced text is promised from the same authors in the future. But the current text largely succeeds in its aim, which is to provide broad coverage of the subject, including examples, without resorting to undue mathematical expansion and rigour.

There are eight self-standing chapters that are interrelated. The book can be read from the beginning as a primer, or each chapter can be used as a focus for a detailed examination of the approaches to the subject.

Chapter one is a general introduction, dealing with physical aspects and some practical consequences. Two following chapters address the application of statistical tools and the important issue of time and length scales. Chapter four reviews the important "basic theory" including single point selection of statistical formulations. Classical models of jet, waves and boundary layers, which are of major practical interest, are covered in chapter five. Chapters six and seven treat spectral analysis of turbulent flows and a number of theories of turbulence based upon consideration of spectral characteristics. The final chapter deals with numerical simulation, including the commonly practised approximation provided by large-eddy simulation methods.

The chapters are well balanced and self-contained and the reader is naturally guided through the subject. Each has sufficient referencing to allow an expansion of the basic material - clearly a deliberate intention of the authors, who deserve credit for dealing with many complex subjects in a clear and sympathetic manner. This is the good feature of the book. It provides a balanced introduction to the main elements of the study of turbulence in an uncluttered and literary fashion.

The downside is that the student and practitioner will not find the text substantial enough to go out and deal directly with specific complex problems. The subject is too broad and subtle in its nature and the potential methods of approach too large to allow for this in a single text.

But the authors' compromise is sensible and the book does provide an easily digestible introduction to turbulent flows.

Brian Briscoe is professor of interface engineering, Imperial College, London.