An Informal Introduction To Turbulence

To Turbulence by ARKADY TSINOBER Department of Fluid Mechanics, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel KLUWER ACADEMIC PUBLISHERS NEW YORK, BOSTON, DORDRECHT, LONDON, MOSCOW eBookISBN: 0-306-48384-X Print ISBN: 1-4020-0110-X ©2004 Kluwer Academic Publishers NewYork, Boston, Dordrecht, London, Moscow Print ©2001 Kluwer Academic Publishers Dordrecht All rights reserved No part of this eBook maybe reproducedor transmitted inanyform or byanymeans, electronic, mechanical, recording, or otherwise, without written consent from the Publisher Created in the United States of America Visit Kluwer Online at: http://kluweronline. com and Kluwer's eBookstoreat: http://ebooks. kluweronline. com TO My WITS TABLE OF CONTENTS 1 INTRODUCTION 1 Brief history 1 1. 1 1. 2 Nature and major qualitative universal features of turbulent flows 2 1. 2. 1 Representative examples of turbulent flows 2 1. 2. 2 In lieu of definition: major qualitative universal f- tures of turbulent flows 15 1. 3 Why turbulence is so impossibly difficult? The three N's 19 On the Navier-Stokes equations 19 1. 3. 1 1. 3. 2 On the nature of the problem 21 1. 3. 3 Nonlinearity 22 1. 3. 4 Noninegrability 22 Nonlocality 1. 3. 5 23 1. 3. 6 On physics of turbulence 24 1. 3. 7 On statistical theories 24 1. 4 Outline of the following material 25 1. 5 In lieu of summary 26 2 ORIGINS OF TURBULENCE 27 2. 1 Instability 27 2. 2 Transition to turbulence versus routes to chaos 29 2.

This fully revised second edition focuses on physical phenomena and observations in turbulence, and is focused on reversing misconceptions and ill-defined concepts. New topics include ergodicity, Eulerian versus Lagrangian descriptions, theory validation, and anomalous scaling.

Based on a taught by the author at the University of Cambridge, this comprehensive text on turbulence and fluid dynamics is aimed at year 4 undergraduates and graduates in applied mathematics, physics, and engineering, and provides an ideal reference for industry professionals and researchers. It bridges the gap between elementary accounts of turbulence found in undergraduate texts and more rigorous accounts given in monographs on the subject. Containing many examples, the author combines the maximum of physical insight with the minimum of mathematical detail where possible. The text is highly illustrated throughout, and includes colour plates; required mathematical techniques are covered in extensive appendices. The text is divided into three parts: Part I consists of a traditional introduction to the classical aspects of turbulence, the nature of turbulence, and the equations of fluid mechanics. Mathematics is kept to a minimum, presupposing only an elementary knowledge of fluid mechanics and statistics. Part II tackles the problem of homogeneous turbulence with a focus on describing the phenomena in real space. Part III covers certain special topics rarely discussed in introductory texts. Many geophysical and astrophysical flows are dominated by the effects of body forces, such as buoyancy, Coriolis and Lorentz forces. Moreover, certain large-scale flows are approximately two-dimensional and this has led to a concerted investigation of two-dimensional turbulence over the last few years. Both the influence of body forces and two-dimensional turbulence are discussed.

Beginning with a description of turbulence, its various manifestations, and a brief history of study, this text also incorporates modern perspectives on turbulence. The text also covers such topics as intermittency and the resultant conditional sampling and averaging of turbulent flows, the role of large scale computation of the fundamental equations of fluid mechanics in providing information on variables, and asymptotic methods which are used to expose important features of turbulent flows. Meaningful exercises are included in every section.

This book offers a unique multidisciplinary integration of the physics of turbulence and remote sensing technology. Remote Sensing of Turbulence provides a new vision on the research of turbulence and summarizes the current and future challenges of monitoring turbulence remotely. The book emphasizes sophisticated geophysical applications, detection, and recognition of complex turbulent flows in oceans and the atmosphere. Through several techniques based on microwave and optical/IR observations, the text explores the technological capabilities and tools for the detection of turbulence, their signatures, and variability. FEATURES Covers the fundamental aspects of turbulence problems with a broad geophysical scope for a wide audience of readers Provides a complete description of remote-sensing capabilities for observing turbulence in the earth’s environment Establishes the state-of-the-art remote-sensing techniques and methods of data analysis for turbulence detection Investigates and evaluates turbulence detection signatures, their properties, and variability Provides cutting-edge remote-sensing applications for space-based monitoring and forecasts of turbulence in oceans and the atmosphere This book is a great resource for applied physicists, the professional remote sensing community, ecologists, geophysicists, and earth scientists.

Now in its second edition, this book clearly, concisely and comprehensively outlines the essence of turbulence. In view of the absence of a theory based on first principles and adequate tools to handle the problem, the “essence” of turbulence, i.e. what turbulence really is from a fundamental point of view, is understood empirically through observations from nature, laboratories and direct numerical simulations rather than explained by means of conventional formalistic aspects, models, etc., resulting in pertinent issues being described at a highly theoretical level in spite of the mentioned lack of theory. As such, the book highlights and critically reexamines fundamental issues, especially those of paradigmatic nature, related to conceptual and problematic aspects, key misconceptions and unresolved matters, and discusses why the problem is so difficult. As in the previous edition, the focus on fundamental issues is also a consequence of the view that without corresponding advances in fundamental aspects there is little chance of progress in any applications. More generally there is a desperate need for physical fundamentals of a great variety of processes in nature and technology in which turbulence plays a central role. Turbulence is omnipresent throughout the natural sciences and technology, but despite the vast sea of information available the book retains its brevity without oversimplifications, making it of interest to a broad audience.

This book provides state-of-the-art results and theories in homogeneous turbulence, including anisotropy and compressibility effects with extension to quantum turbulence, magneto-hydodynamic turbulence and turbulence in non-newtonian fluids. Each chapter is devoted to a given type of interaction (strain, rotation, shear, etc.), and presents and compares experimental data, numerical results, analysis of the Reynolds stress budget equations and advanced multipoint spectral theories. The role of both linear and non-linear mechanisms is emphasized. The link between the statistical properties and the dynamics of coherent structures is also addressed. Despite its restriction to homogeneous turbulence, the book is of interest to all people working in turbulence, since the basic physical mechanisms which are present in all turbulent flows are explained. The reader will find a unified presentation of the results and a clear presentation of existing controversies. Special attention is given to bridge the results obtained in different research communities. Mathematical tools and advanced physical models are detailed in dedicated chapters.

Most natural and industrial flows are turbulent. The atmosphere and oceans, automobile and aircraft engines, all provide examples of this ubiquitous phenomenon. In recent years, turbulence has become a very lively area of scientific research and application, attracting many newcomers who need a basic introduction to the subject. An Introduction to Turbulent Flow, first published in 2000, offers a solid grounding in the subject of turbulence, developing both physical insight and the mathematical framework needed to express the theory. It begins with a review of the physical nature of turbulence, statistical tools, and space and time scales of turbulence. Basic theory is presented next, illustrated by examples of simple turbulent flows and developed through classical models of jets, wakes, and boundary layers. A deeper understanding of turbulence dynamics is provided by spectral analysis and its applications. The final chapter introduces the numerical simulation of turbulent flows. This well-balanced text will interest graduate students in engineering, applied mathematics, and the physical sciences.