The aeronautics industry is presently aiming for faster design cycles and shorter time to market of new aircraft. It is looking at the same time for improved aerodynamic performance, for evident competitive reasons. Advanced, computer based design systems, including fast and reliable numerical flow solvers, have been developed in the last decade including new turbulence models. On the experimental side, measurement techniques in general have also been improved significantly, however the data evaluation process remains still very time consuming, and unsteady effects and turbulence are often not being captured with sufficient accuracy and detail. The development of Particle Image Velocimetry (PIV) has helped to improve the analysis of the flow fields. After investigations in laboratory scale wind tunnels, a joint initiative on PIV research, by the European Aerospace Research Establishments, within GARTEUR have enabled a wide breakthrough of this new technology in Europe. Within the Research Framework Program of the European Union, the joint research project EUROPIV aimed to apply PIV technology to problems of industrial interest.

Despite the fact that fluid dynamics and filtration through porous media and mathematics, there are classical research areas in engineering, physics, are still many industrial processes that require the study of new mathemat ical models for flows of particular complexity, due to the peculiar properties of the systems involved. The aim of this book is to provide a number of examples showing how frequently such situations arise in various branches of industrial technology. The selection of the subjects was motivated not only by their industrial rel evance and mathematical interest. What I had in mind was a collection of problems having a really distinctive character, thus bringing some fresh air into one of the oldest and most revered domains of applied mathematics. The incredible richness of nonstandard flow problems in industrial appli cations has always been, and still is, a constant surprise to me. Therefore I tried to offer a very large spectrum of subjects, with special attention devoted to those problems in which the modeling phase is far from being obvious, and the mathematical content is absolutely nontrivial. With such a view to diversity, topics have been selected from a variety of sources (such as glass industry, polymers science, coffee brewing, fuels pipelining), and contributors from different backgrounds (mathematics, physics, chemical engineering) have been included. Consequently, the mathematical nature of the problems formulated spans over a large range, so that their theoret ical investigation and numerical computation require a variety of different techniques."

Environmental Tracers in Subsurface Hydrology synthesizes the research of specialists into a comprehensive review of the application of environmental tracers to the study of soil water and groundwater flow. The book includes chapters which cover ionic tracers, noble gases, chlorofluorocarbons, tritium, chlorine-36, oxygen-18, deuterium, and isotopes of carbon, strontium, sulphur and nitrogen. Applications of the tracers include the estimation of vertical and horizontal groundwater velocities, groundwater recharge rates, inter-aquifer leakage and mixing processes, chemical processes and palaeohydrology. Practicing hydrologists, soil physicists and hydrology professors and students will find the book to be a valuable support in their work.

The practical importance of turbulence led the U.K. Royal Academy of Engineering to launch an Initiative on Turbulence, the most important outcome of which was the definition and agreement of the 1999 Newton Institute Research Programme on Turbulence. The main aim of the- month programme, held at the institute in Cambridge, was to bring together the mathematics and engineering communities involved in the turbulence area to address the many problems and to map out future strategy. As a part of the Research Programme, a Symposium on Direct and Large-Eddy Simulation was jointly organised with ERCOFfAC through their Large-Eddy Simulation Interest Group and took place in May 1999. Two previous ERCOFf AC Workshops had already taken place on these closely related varieties of turbulence simulation, at The University of Surrey in 1994 and at Universite Joseph Fourier, Grenoble in 1996. The Symposium at Cambridge was therefore the third in the ERCOFTAC series, enhanced by the presence of leading figures in the field from Europe and the USA who were resident at INI for that period of the Research Programme. Professors M. Germano, A. Leonard, J. Jimenez, R. Kerr and S. Sarkar gave the invited lectures, text versions of which will be found in this volume. As occurred at the previous two ERCOFT AC workshops, there were almost one hundred participants mostly from Europe but including some from Japan and the USA, including on this occasion resident scientists of the INI Research Programme.

This book describes an engineering approach based on interactive boundary-layer and stability-transition theories, both developed by the author, for calculating aerodynamic flows. The contents include two-dimensional and three-dimensional steady and unsteady flows with and without compressibility effects. The former theory is based on the numerical solutions of the reduced Navier-Stokes equations in which Euler and boundary-layer equations are coupled with an interaction law. The latter theory is based on the linear stability theory and employs the so-called en method. The book details applications of this approach to airfoils, wings and high lift systems. It is intended for undergraduate and graduate students and practicing engineers interested in aerodynamics, hydrodynamics and modern numerical methods and computer programs for solving linear and nonlinear ordinary and parabolic partial differential equations.

This single-volume work gives an introduction to the fields of transition, turbulence, and combustion modeling of compressible flows and provides the physical background for today's modeling approaches in these fields. It presents basic equations and discusses fundamental aspects of hydrodynamical instability.

Rapid advances in Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES) of turbulence provide opportunities for improved prediction of incompressible and compressible turbulent flows. The book includes five invited and thirty-eight contributed papers presented at the Second AFOSR International Conference on DNS and LES held at Rutgers - The State University of New Jersey, on June 7-9, 1999. A broad range of topics in DNS and LES are presented, including new developments in LES modeling, numerical algorithms for LES and DNS, DNS and LES of reacting flows, and DNS and LES for supersonic and hypersonic boundary layers. The book provides a extensive view of the state of the art in DNS and LES.

This book provides a compilation of important optical techniques applied to experiments in heat and mass transfer, multiphase flow and combustion. The emphasis of this book is on the application of these techniques to various engineering problems. The contributions are aiming to provide practicing engineers, both in industry and research, with the recent state-of-science in the application of advanced optical measurements. The book is written by selected specialists representing leading experts in this field who present new information for the possibilities of these techniques and give stimulation of new ideas for their application.

This volume contains the Proceedings of the IUTAM Symposium on Mechanics of Passive and Active Flow Control, held at the DLR, GAttingen, in September 1998. This follows an earlier IUTAM Symposium on Turbulence Management and Relaminarisation which was held in Bangalore in 1987. The last decade has witnessed significant advances and research activity in the area of flow control/management, triggered by technological applications as well as scientific curiosity in understanding the structure of complex flows. This volume contains both review and contributed papers in the area of flow control, with emphasis on fluid dynamical mechanisms underlying different passive and active control techniques used in a variety of flows such as bumps, roughnesses, riblets, vortex generators, suction blowing, sound and MEMS; issues such as new control concepts and control strategies are also addressed. The application areas include drag reduction, transition, turbulence and separation, many relevant to aeronautical systems. This volume is very timely and contains a wealth of information on current research in the broad subject of flow control concepts and applications; it should be of particular interest to scientists, engineers and students pursuing research in flow control.

The subject of the book is directly related to environmental noise and vibration phenomena (sound emission by vibrating structures, prediction and reduction, ...). Transportation noise is one of the main applications. The book presents an overview of the most recent knowledge on interaction phenomena between a structure and a fluid, including nonlinear aspects. It covers all aspects of the phenomena, from the mathematical modeling up to the applications to automotive industrial problems. The aim is to provide readers with a good understanding of the physical phenomena as well as the most recent knowledge of predictive methods.

This book is designed to fulfill a dual role. On the one hand it provides a description of the rheological behavior of molten poly mers. On the other, it presents the role of rheology in melt processing operations. The account of rheology emphasises the underlying principles and presents results, but not detailed deriva tions of equations. The processing operations are described qualita tively, and wherever possible the role of rheology is discussed quantitatively. Little emphasis is given to non-rheological aspects of processes, for example, the design of machinery. The audience for which the book is intended is also dual in nature. It includes scientists and engineers whose work in the plastics industry requires some knowledge of aspects of rheology. Examples are the polymer synthetic chemist who is concerned with how a change in molecular weight will affect the melt viscosity and the extrusion engineer who needs to know the effects of a change in molecular weight distribution that might result from thermal degra dation. The audience also includes post-graduate students in polymer science and engineering who wish to acquire a more extensive background in rheology and perhaps become specialists in this area. Especially for the latter audience, references are given to more detailed accounts of specialized topics, such as constitutive relations and process simulations. Thus, the book could serve as a textbook for a graduate level course in polymer rheology, and it has been used for this purpose."

The Second Monte Verita Colloquium Fundamental Problematic Issues in Turbu lence was held in Monte Verita, Switzerland, on March 23-27, 1998. The main goal of the Colloquium was to bring together in the relaxed atmo sphere of Monte Verita a group of leading scientists (consisting of representatives of different generations) and to discuss informally and free of the influence of funding agencies and/or other "politics" of nonscientific nature the basic issues of turbulence. The intention was to put major emphasis on the exposition of the problematic aspects and discussion(s) - not mere reporting of results, i. e. not hav ing just one more meeting. For this purpose it was originally thought to leave all the afternoons free of formal presentations at all. However, this intention became unrealistic due to a number of reasons, and, in the first place, due to strong pres sure from various parts of the scientific community and non-scientific constraints to broaden the scope and to increase the number of participants as compared to the First Colloquium held in 1991. This resulted in a considerable reduction of time for discussions. Nevertheless, the remaining time for discussions was much larger than usually allocated at scientific conferences. On the scientific side the main idea was to bring together scientists work ing in turbulence from different fields, such as mathematics, physics, engineering and others. In this respect the Colloquium was definitely very successful and re sulted in a number of interesting interactions and contacts."

This book presents a critical and modern analysis of the conceptual foundations of statistical mechanics as laid down in Boltzmann's works. The author emphasises the relation between microscopic reversibility and macroscopic irreversibility. Students will find a clear and detailed explanation of fundamental concepts such as equipartition, entropy and ergodicity. They will learn about Brownian motion, the modern treatment of the thermodynamic limit phase transitions, the microscopic and macroscopic theory of the coexistence of phases, statistical mechanics of stationary states, and fluctuations and dissipation in chaotic motions.

In 1999, the International Centre for Mechanical Sciences celebrates t hirty years of activity. For this celebration CISM has organized a ser ies of courses and meetings on environmental problems, one of the lead ing subjects today of theoretical and applied research all over the wo rld. The results obtained directly influence our daily life, particula rly in applications for protection from pollution and natural hazards. The most significant of the events was the Conference on Environment al Applications of Mechanics and Computer Science, where prominent sci entists in the field present significant examples of the scientific ap proach to large scale phenomena involved in environmental problems.

This monograph aims to fill the gap between the mathematical literature which significantly contributed during the last decade to the understanding of the collapse phenomenon, and applications to domains like plasma physics and nonlinear optics where this process provides a fundamental mechanism for small scale formation and wave dissipation. This results in a localized heating of the medium and in the case of propagation in a dielectric to possible degradation of the material. For this purpose, the authors have chosen to address the problem of wave collapse by several methods ranging from rigorous mathematical analysis to formal asymptotic expansions and numerical simulations.

Turbulence modeling both addresses a fundamental problem in physics, 'the last great unsolved problem of classical physics, ' and has far-reaching importance in the solution of difficult practical problems from aeronautical engineering to dynamic meteorology. However, the growth of supercom puter facilities has recently caused an apparent shift in the focus of tur bulence research from modeling to direct numerical simulation (DNS) and large eddy simulation (LES). This shift in emphasis comes at a time when claims are being made in the world around us that scientific analysis itself will shortly be transformed or replaced by a more powerful 'paradigm' based on massive computations and sophisticated visualization. Although this viewpoint has not lacked ar ticulate and influential advocates, these claims can at best only be judged premature. After all, as one computational researcher lamented, 'the com puter only does what I tell it to do, and not what I want it to do. ' In turbulence research, the initial speculation that computational meth ods would replace not only model-based computations but even experimen tal measurements, have not come close to fulfillment. It is becoming clear that computational methods and model development are equal partners in turbulence research: DNS and LES remain valuable tools for suggesting and validating models, while turbulence models continue to be the preferred tool for practical computations. We believed that a symposium which would reaffirm the practical and scientific importance of turbulence modeling was both necessary and timely."

Micropolar fluids are fluids with microstructure belonging to a class of fluids with nonsymmetrical stress sensor referred to as polar fluids. Physically, they represent fluids consisting of randomly oriented particles suspended in a viscous medium, and they are important to engineers and scientists working with hydrodynamic-fluid problems and phenomena.

The goal of this volume is to provide a comprehensive exposition of the principles and methods of micropolar fluids for a broad readership in the science and engineering of fluid mechanics. Organized into three parts, the first part of the book presents the basic model of micropolar fluids, with necessary background information. Provided in the second part is a thorough presentation of the analysis of the mathematics of motion of micropolar fluids, with many detailed examples. Some select and important applications in the topics of lubrication theory and porous media are discusssed in the third part.

Topics and Features:

* Comprehensive and unified view of the subject, with clear foundations for the basic model

* Chapter exercises and carefully chosen examples to reinforce the material

* Coverage of numerical algorithm for behavior of micropolar fluids in a bounded domain

* Discussions of exact solutions for microrotation and velocity fields for some classical fluids flows

This study serves as an up-to-date and comprehensive reference for mathematicians, scientists, and engineers. Micropolar Fluids is an essential resource for anyone wishing to understand and needing to use concepts and methods when working with the hydrodynamics of miropolar fluids.

This book provides a general introduction to fluid mechanics in the form of biographies and popular science. Based on the author's extensive teaching experience, it combines natural science and human history, knowledge inheritance and cognition law to replace abstract concepts of fluid mechanics with intuitive and understandable physical concepts. In seven chapters, it describes the development of fluid mechanics, aerodynamics, hydrodynamics, computational fluid dynamics, experimental fluid dynamics, wind tunnel and water tunnel equipment, the mystery of flight and aerodynamic principles, and leading figures in fluid mechanics in order to spark beginners' interest and allow them to gain a comprehensive understanding of the field's development. It also provides a list of references for further study.

1. Objective and Scope Bubbles, drops and rigid particles occur everywhere in life, from valuable industrial operations like gas-liquid contracting, fluidized beds and extraction to such vital natural processes as fermentation, evaporation, and sedimentation. As we become increasingly aware of their fundamental role in industrial and biological systems, we are driven to know more about these fascinating particles. It is no surprise, therefore, that their practical and theoretical implications have aroused great interest among the scientific community and have inspired a growing number of studies and publications. Over the past ten years advances in the field of small Reynolds numbers flows and their technological and biological applications have given rise to several definitive monographs and textbooks in the area. In addition, the past three decades have witnessed enormous progress in describing quantitatively the behaviour of these particles. However, to the best of our knowledge, there are still no available books that reflect such achievements in the areas of bubble and drop deformation, hydrodynamic interactions of deformable fluid particles at low and moderate Reynolds numbers and hydrodynamic interactions of particles in oscillatory flows. Indeed, only one more book is dedicated entirely to the behaviour of bubbles, drops and rigid particles ["Bubbles, Drops and Particles" by Clift et al. (1978)] and the authors state its limitations clearly in the preface: "We treat only phenomena in which particle-particle interactions are of negligible importance. Hence, direct application of the book is limited to single-particle systems of dilute suspensions.

This book is devoted to an investigation of some important problems of mod ern filtering theory concerned with systems of 'any nature being able to per ceive, store and process an information and apply it for control and regulation'. (The above quotation is taken from the preface to 27]). Despite the fact that filtering theory is l'argely worked out (and its major issues such as the Wiener-Kolmogorov theory of optimal filtering of stationary processes and Kalman-Bucy recursive filtering theory have become classical) a development of the theory is far from complete. A great deal of recent activity in this area is observed, researchers are trying consistently to generalize famous results, extend them to more broad classes of processes, realize and justify more simple procedures for processing measurement data in order to obtain more efficient filtering algorithms. As to nonlinear filter ing, it remains much as fragmentary. Here much progress has been made by R. L. Stratonovich and his successors in the area of filtering of Markov processes. In this volume an effort is made to advance in certain of these issues. The monograph has evolved over many years, coming of age by stages. First it was an impressive job of gathering together the bulk of the impor tant contributions to estimation theory, an understanding and moderniza tion of some of its results and methods, with the intention of applying them to recursive filtering problems."

TUrbulence modeling encounters mixed evaluation concerning its impor tance. In engineering flow, the Reynolds number is often very high, and the direct numerical simulation (DNS) based on the resolution of all spatial scales in a flow is beyond the capability of a computer available at present and in the foreseeable near future. The spatial scale of energetic parts of a turbulent flow is much larger than the energy dissipative counterpart, and they have large influence on the transport processes of momentum, heat, matters, etc. The primary subject of turbulence modeling is the proper es timate of these transport processes on the basis of a bold approximation to the energy-dissipation one. In the engineering community, the turbulence modeling is highly evaluated as a mathematical tool indispensable for the analysis of real-world turbulent flow. In the physics community, attention is paid to the study of small-scale components of turbulent flow linked with the energy-dissipation process, and much less interest is shown in the foregoing transport processes in real-world flow. This research tendency is closely related to the general belief that universal properties of turbulence can be found in small-scale phenomena. Such a study has really contributed much to the construction of statistical theoretical approaches to turbulence. The estrangement between the physics community and the turbulence modeling is further enhanced by the fact that the latter is founded on a weak theoretical basis, compared with the study of small-scale turbulence."

Recent advances in boundary-layer theory have shown how modern analytical and computational techniques can and should be combined to deepen the understanding of high Reynolds number flows and to design effective calculation strategies. This is the unifying theme of the present volume which addresses laminar as well as turbulent flows.

Speckle photography is an advanced experimental technique used for quantitatve determination of density, velocity and temperature fields in gas, liquid, and plasma flows. This book presents the most important equations for the diffraction theory of speckle formation and the statistical properties of speckle fields. It also describes experimental set-ups and the equipment needed to implement these methods. Speckle photography methods for automatic data acquisition and processing are considered and examples for their use are given.

Twenty-one years have passed since the first symposium in this series was held in Paris (1976). Since then there have been meetings in Lausanne (1980), Cambridge (1984), Aachen (1987), Beijing (1989), Notre Dame (1991) and Fukuoka (1994). During this period a tremendous development in the field of unsteady aerodynamics and aeroelasticity in turbomachines has taken place. As steady-state flow conditions become better known, and as blades in the turbomachine are constantly pushed towards lower weight, and higher load and efficiency, the importance of unsteady phenomena appear more clearly. th The 8 Symposium was, as the previous ones, of high quality. Furthermore, it presented the audience with the latest developments in experimental, numerical and theoretical research. More papers than ever before were submitted to the conference. As the organising committee wanted to preserve the uniqueness of the symposium by having single sessions, and thus mingle speakers and audience with different backgrounds in this interdisciplinary field, only a limited number of papers could be accepted. 54 papers were accepted and presented at the meeting, all of which are included in the present proceedings.

This collection of classic papers in shock compression science makes available not only some of the most important classic papers on shock waves by Poisson, Rankine, Earnshaw, Riemann, and Hugoniot, which remain important references, but also some pathbreaking papers from the 1940s and 1950s on shocks in solids and fluids by such theorists as Bethe, and Weyl. Although their ideas and results remain of current interest, many of these papers have been hard to find, since the journals in which they were published are not available in many libraries. The editors have also translated papers written in French to make them accessible to a wider audience. This collection is thus not only a valuable historical resource but also a vital reference for those working in the field.