For the past several decades, the study of free boundary problems has been a very active subject of research occurring in a variety of applied sciences. What these problems have in common is their formulation in terms of suitably posed initial and boundary value problems for nonlinear partial differential equations. Such problems arise, for example, in the mathematical treatment of the processes of heat conduction, filtration through porous media, flows of non-Newtonian fluids, boundary layers, chemical reactions, semiconductors, and so on. The growing interest in these problems is reflected by the series of meetings held under the title "Free Boundary Problems: Theory and Applications" (Ox ford 1974, Pavia 1979, Durham 1978, Montecatini 1981, Maubuisson 1984, Irsee 1987, Montreal 1990, Toledo 1993, Zakopane 1995, Crete 1997, Chiba 1999). From the proceedings of these meetings, we can learn about the different kinds of mathematical areas that fall within the scope of free boundary problems. It is worth mentioning that the European Science Foundation supported a vast research project on free boundary problems from 1993 until 1999. The recent creation of the specialized journal Interfaces and Free Boundaries: Modeling, Analysis and Computation gives us an idea of the vitality of the subject and its present state of development. This book is a result of collaboration among the authors over the last 15 years."

The primary objective of this monograph is to develop an elementary and se- containedapproachtothemathematicaltheoryofaviscousincompressible?uid n in a domain ? of the Euclidean spaceR , described by the equations of Navier- Stokes. The book is mainly directed to students familiar with basic functional analytic tools in Hilbert and Banach spaces. However, for readers' convenience, in the ?rst two chapters we collect, without proof some fundamental properties of Sobolev spaces, distributions, operators, etc. Another important objective is to formulate the theory for a completely general domain ?. In particular, the theory applies to arbitrary unbounded, non-smooth domains. For this reason, in the nonlinear case, we have to restrict ourselves to space dimensions n=2,3 that are also most signi?cant from the physical point of view. For mathematical generality, we will develop the l- earized theory for all n? 2. Although the functional-analytic approach developed here is, in principle, known to specialists, its systematic treatment is not available, and even the diverseaspectsavailablearespreadoutintheliterature.However,theliterature is very wide, and I did not even try to include a full list of related papers, also because this could be confusing for the student. In this regard, I would like to apologize for not quoting all the works that, directly or indirectly, have inspired this monograph.

This is the first volume of a set of two devoted to the operator approach to linear problems in hydrodynamics. It presents functional analytical methods applied to the study of small movements and normal oscillations of hydromechanical systems having cavities filled with either ideal or viscous fluids. The work is a sequel to and at the same time substantially extends the volume "Operator Methods in Linear Hydrodynamics: Evolution and Spectral Problems" by N.D. Kopachevsky, S.G. Krein and Ngo Zuy Kan, published in 1989 by Nauka in Moscow. It includes several new problems on the oscillations of partially dissipative hydrosystems and the oscillations of visco-elastic or relaxing fluids. The work relies on the authors' and their students' works of the last 30-40 years. The readers are not supposed to be familiar with the methods of functional analysis. In the first part of the present volume, the main facts of linear operator theory relevant to linearized problems of hydrodynamics are summarized, including elements of the theories of distributions, self-adjoint operators in Hilbert spaces and in spaces with an indefinite metric, evolution equations and asymptotic methods for their solutions, the spectral theory of operator pencils. The book is particularly useful for researchers, engineers and students in fluid mechanics and mathematics interested in operator theoretical methods for the analysis of hydrodynamical problems.

Free surface flows arise in the natural world, physical and biological sciences and in some areas of modern technology and engineering. Exam ples include the breaking of sea waves on a harbour wall, the transport of sloshing fluids in partly filled containers, and the design of micronozzles for high speed ink-jet printing. Apart from the intrinsic mathematical challenge in describing and solving the governing equations, there are usually important environmental, safety and engineering features which need to be analysed and controlled. A rich variety of techniques has been developed over the past two decades to facilitate this analysis; singular perturbations, dynamical systems, and the development of sophisticated numerical codes. The extreme and sometimes violent nature of some free surface flows taxes these methods to the limit. The work presented at the symposium addressed these limits and can be loosely classified into four areas: (i) Axisymmetric free surface flows. There are a variety of problems in the printing, glass, fertiliser and fine chemical industries in which threads of fluid are made and controlled. Presentations were made in the areas of pinch-off for inviscid and viscous threads of fluid, recoil effects after droplet formation and the control of instability by forced vibration. (ii) Dynamic wetting. The motion of three phase contact lines, which are formed at the junction between two fluids and a solid, plays an important role in fluid mechanics."

Mathematical modeling and numerical simulation in fluid mechanics are topics of great importance both in theory and technical applications. The present book attempts to describe the current status in various areas of research. The 10 chapters, mostly survey articles, are written by internationally renowned specialists and offer a range of approaches to and views of the essential questions and problems. In particular, the theories of incompressible and compressible Navier-Stokes equations are considered, as well as stability theory and numerical methods in fluid mechanics. Although the book is primarily written for researchers in the field, it will also serve as a valuable source of information to graduate students.

Controlling turbulence is an important issue for a number of technological applications. Several methods to modulate turbulence are currently being investigated. All of them are based on the introduction of some sort of perturbation into the flow field which affects turbulence coherent structures responsible for turbulence transfer mechanisms.The book describes several aspects of turbulence structure and modulation and explains and discusses the most promising techniques in detail.

The goal of this book is to present the new trend of Computational Fluid Dynamics (CFD) for the 21 st Century. It consists of papers presented at a symposium honoring Prof. No buyuki Satofuka on the occasion of his 60th birthday. The symposium entitled Computational Fluid Dynamics fOT the 21st Century was held at Kyoto Institute of Technology (KIT) in Kyoto, Japan on July 15-17,2000. The symposium was hosted by KIT as a memorial event celebrating the 100 year anniversary of this establishment. The invited speakers were from Ja pan as weil as from the international community in Asia, Europe and North America. It is a great pleasure to dedicate this book to Prof. Satofuka in appreciation ofhis contributions to this field. During the last 30 years, Prof. Satofuka made many important contributions to CFD ad vancing the numerics and our understanding of flow physics in different regimes. The details of his contributions are discussed in the first chapter. The book contains chapters covering re lated topics with emphasis on new promising directions for the 21 st Century. The chapters of the book reflect the 10 sessions of the symposium on both the numerics and the applications including grid generation and adaptation, new numerical schemes, optimi zation techniques and parallel computations as weil as applications to multi-sc ale and multi physics problems, design and flow control and new topics beyond aeronautics. In the follow ing, the chapters of the book are introduced."

Crystal growth, casting, soldering, welding, high-energy surface treatment, nuclear safety systems and geophysical flows are just a few examples where solidification and convection occur together. These processes are interactive on micro- and macroscales: flow affects the distribution of heat and species and hence the freezing process, while solidification evolves flow boundaries, as in crusting, for example, and hence can radically alter the convection. Mathematical modellers, experimentalists and applied scientists were invited to this colloquium with the aim of consolidating our understanding of such interactions, of identifying key outstanding issues, and of developing new approaches in this important area of fundamental research. Both invited and contributed papers focus on both fundamental and technologically relevant problems.

This book provides a comprehensive overview of the recent developments in river, coastal and estuarine morphodynamics through a collection of review papers written by well-recognized experts in the field. Apart from geoscientists, it is also of special interest to people involved in fluid mechanics who want to understand near wall turbulence and the effects of coherent structures on the mechanisms of sediment transports. Though aimed at geomorphologists and sedimentologists, the terminology employed in the book makes it generally accessible to engineers, physicists and applied mathematicians at the postgraduate level. The contributions are well-illustrated with splendid pictures of various morphodynamic natural patterns.

The book focuses on the main physical ideas and mathematical methods of the microscopic theory of fluids, starting with the basic principles of statistical mechanics. The detailed derivation of results is accompanied by explanation of their physical meaning. The same approach refers to several specialized topics of the liquid state, most of which are recent developments, such as: a perturbation approach to the surface tension, an algebraic perturbation theory of polar nonpolarizable fluids and ferrocolloids, a semi-phenomenological theory of the Tolman length and some others. The book addresses researchers as well as graduate students in physics and chemistry with research interests in the statistical physics of fluids.

Computation of Unsteady Internal Flows provides an in-depth understanding of unsteady flow modeling and algorithms. This understanding enables suitable algorithms and approaches for particular fields of application to be selected. In addition, the understanding of the behavior of algorithms gained allows practitioners to use them more safely in existing codes, enabling meaningful results to be produced more economically. Features of Computation of Unsteady Internal Flows: Specialized unsteady flow modeling algorithms, their traits, and practical tips relating to their use are presented. Case studies considering complex, practically significant problems are given. Source code and set-up files are included. Intended to be of a tutorial nature, these enable the reader to reproduce and extend case studies and to further explore algorithm performances. Mathematical derivations are used in a fashion that illuminates understanding of the physical implications of different numerical schemes. Physically intuitive mathematical concepts are used. New material on adaptive time stepping is included. GBP/LISTGBP Audience: Researchers in both the academic and industrial areas who wish to gain in-depth knowledge of unsteady flow modeling will find Computation of Unsteady Internal Flows invaluable. It can also be used as a text in courses centered on computational fluid dynamics.

This volume contains the proceedings of the CEAS/DragNet European Drag Reduction Conference 2000. The conference addressed the recent advances in all areas of drag reduction research, development, validation and demonstration including laminar flow technology, adaptive wing concepts, turbulent and induced drag reduction, separation control and supersonic flow aspects. This volume is of particular interest to engineers, scientists and students working in the aeronautics industry, research establishments or academia.

This book offers to students, engineers, CFD modelers, and scientists a detailed synthetic presentation of turbulence physics and modeling with the possibility to find a quick route through the jungle of publications and models. Chapters 1 to 4 show that turbulence models may be derived and analyzed in a physically sound manner with their potential merits and drawbacks. Chapters 5 and 6 review the physics of (inhomogenous) turbulent flows starting from the most simple flow cases and adding more and more complexity. The status and uncertainties of available experimental data and the practical performance of currently available turbulent models are discussed.

This book is concerned with the methods of solving the nonlinear Boltz mann equation and of investigating its possibilities for describing some aerodynamic and physical problems. This monograph is a sequel to the book 'Numerical direct solutions of the kinetic Boltzmann equation' (in Russian) which was written with F. G. Tcheremissine and published by the Computing Center of the Russian Academy of Sciences some years ago. The main purposes of these two books are almost similar, namely, the study of nonequilibrium gas flows on the basis of direct integration of the kinetic equations. Nevertheless, there are some new aspects in the way this topic is treated in the present monograph. In particular, attention is paid to the advantages of the Boltzmann equation as a tool for considering nonequi librium, nonlinear processes. New fields of application of the Boltzmann equation are also described. Solutions of some problems are obtained with higher accuracy. Numerical procedures, such as parallel computing, are in vestigated for the first time. The structure and the contents of the present book have some com mon features with the monograph mentioned above, although there are new issues concerning the mathematical apparatus developed so that the Boltzmann equation can be applied for new physical problems. Because of this some chapters have been rewritten and checked again and some new chapters have been added."

This volume contains the papers presented at the IUTAM Symposium on Geometry and Statistics of Turbulence, held in November 1999, at the Shonan International Village Center, Hayama (Kanagawa-ken), Japan. The Symposium was proposed in 1996, aiming at organizing concen trated discussions on current understanding of fluid turbulence with empha sis on the statistics and the underlying geometric structures. The decision of the General Assembly of International Union of Theoretical and Applied Mechanics (IUTAM) to accept the proposal was greeted with enthusiasm. Turbulence is often characterized as having the properties of mixing, inter mittency, non-Gaussian statistics, and so on. Interest is growing recently in how these properties are related to formation and evolution of struc tures. Note that the intermittency is meant for passive scalars as well as for turbulence velocity or rate of dissipation. There were eighty-eight participants in the Symposium. They came from thirteen countries, and fifty-seven papers were presented. The presenta tions comprised a wide variety of fundamental subjects of mathematics, statistical analyses, physical models as well as engineering applications. Among the subjects discussed are (a) Degree of self-similarity in cascade, (b) Fine-scale structures and degree of Markovian property in turbulence, (c) Dynamics of vorticity and rates of strain, (d) Statistics associated with vortex structures, (e) Topology, structures and statistics of passive scalar advection, (f) Partial differential equations governing PDFs of velocity in crements, (g) Thermal turbulences, (h) Channel and pipe flow turbulences, and others.

This symposium continues a long tradition for IUGGjIUTAM symposia going back to "Fundamental Problems in Thrbulence and their Relation to Geophysics" Marseille, 1961. The five topics that were emphasized were: turbulence modeling, statistics of small scales and coherent structures, con vective turbulence, stratified turbulence, and historical developments. The objective was to consider the ubiquitous nature of turbulence in a variety of geophysical problems and related flows. Some history of the contribu tions of NCAR and its alumni were discussed, including those of Jackson R Herring, who has been a central figure at NCAR since 1972. To the original topics we added rotation, which appeared in many places. This includes rotating stratified turbulence, rotating convective turbulence, horizontal rotation that appears in flows over terrain and the role of small scale vorticity in many flows. These complicated flows have recently begun to be simulated by several groups from around the world and this meeting provided them with an excellent forum for exchanging results, plus inter actions with those doing more fundamental work on rotating stratified and convective flows. New work on double diffusive convection was given in two presentations. The history of Large Eddy Simulations was presented and several new approaches to this field were given. This meeting also spawned some interesting interactions between observational side and how to inter pret the observations with modeling and simulations around the theme of particle dispersion in these flows."

A detailed look at some of the more modern issues of hydrodynamic stability, including transient growth, eigenvalue spectra, secondary instability. It presents analytical results and numerical simulations, linear and selected nonlinear stability methods. By including classical results as well as recent developments in the field of hydrodynamic stability and transition, the book can be used as a textbook for an introductory, graduate-level course in stability theory or for a special-topics fluids course. It is equally of value as a reference for researchers in the field of hydrodynamic stability theory or with an interest in recent developments in fluid dynamics. Stability theory has seen a rapid development over the past decade, this book includes such new developments as direct numerical simulations of transition to turbulence and linear analysis based on the initial-value problem.

This is the first book to present a model, based on rational mechanics of electrorheological fluids, that takes into account the complex interactions between the electromagnetic fields and the moving liquid. Several constitutive relations for the Cauchy stress tensor are discussed. The main part of the book is devoted to a mathematical investigation of a model possessing shear-dependent viscosities, proving the existence and uniqueness of weak and strong solutions for the steady and the unsteady case. The PDS systems investigated possess so-called non-standard growth conditions. Existence results for elliptic systems with non-standard growth conditions and with a nontrivial nonlinear r.h.s. and the first ever results for parabolic systems with a non-standard growth conditions are given for the first time. Written for advanced graduate students, as well as for researchers in the field, the discussion of both the modeling and the mathematics is self-contained.

Since the computing revolution, modelling has become the most important way in which we further our knowledge about how the sea moves and how the processes in the sea operate. The coast and the continental shelf are two of the most important areas of the sea to understand. Coastal and Shelf Sea Modelling is therefore very timely and important. In this text, modelling the processes that occur in the sea is motivated continually through real life examples. Sometimes these are incorporated naturally within the text, but there are also a number of case studies taken from the recent research literature. These will be particularly valuable to students as they are presented in a style more readily accessible than that found in a typical research journal. The motivation for modelling is care for the environment. The well publicised problem of global warming, the phenomenon of El Nino, more localised pollution scares caused by tanker accidents and even smaller scale coastal erosion caused by storms all provide motivation for modelling and all get coverage in this text. Particularly novel features of the book include a systematic treatment of the modelling process in a marine context, the inclusion of diffusion in some detail, ecosystems modelling and a brief foray into wave prediction. The final chapter provides the reader with the opportunity to do some modelling; there are many worked examples followed by exercises that readers can try themselves. All answers are provided. Throughout, the style is informal and the technicalities in term of mathematics are kept to a minimum. Coastal and Shelf Sea Modelling is particularly suitable for graduate marine and oceanographic modelling courses, but will also prove useful to coastal engineers and students at any level interested in the quantitative modelling of marine processes. It is stressed that only a minimal level of mathematics (first year calculus or less) is required; the style and content is introductory.

Segregation is a pervasive phenomenon whereby a flowing granular mass consisting of particles with diverse physical properties becomes spatially inhomogeneous. In the industrial sector that deals with the handling and processing of bulk solids, this non-uniformity is highly undesirable since blend homogeneity is generally a stringent requirement of most products. In the arena of geophysical flows, segregation can enhance the destructive capabilities of natural events such as avalanches and landslides. During the last 15 years, these issues have provided motivation and fostered collaborations between the communities of mathematicians, engineers, industrial researchers, and physicists to develop predictive models of segregation by integrating the perspectives and approaches of each. The collection of unique papers brings to light many of the perplexing scientific and technical issues in our current understanding of this complex phenomenon. It addresses advances in experiment, computational modeling and theory. This volume is one of the very few books devoted entirely to problems of segregation of particulate solids.

The origins of turbulent flow and the transition from laminar to turbulent flow are among the most important unsolved problems of fluid mechanics and aerodynamics. Besides being a fundamental question of fluid mechanics, there are many practical applications for information regarding transition location and the details of the subsequent turbulent flow. This proceedings volume contains the papers of two keynote lectures as well as of 104 technical presentations and posters that were presented at the IUTAM Symposium on Laminar-Turbulent Transition in Sedona, Arizona, September 13-17, 1999. The papers published in the present volume document the state of the art in transition research, and therefore, increased emphasis on the various topics covered in this meeting can be expected in the future.

Some words about SCART 2000. SCART stands for science and art. SCART meetings are organized in a loose time sequence by an international group of scientists, most of them fluid-dynamicists. The first meeting was held in Hong-Kong, the second one in Berlin, and the third, and latest, one in Zurich. SCART meetings include a scientific conference and a number of art events. The intention is to restart a dialogue between scientists and artists which was so productive in the past. To achieve this goal several lectures given by scientists at the conference are intended for a broader public. In the proceedings they are denoted as SCART lectures. The artists in tum address the main theme of the conference with their contributions. The lectures at SCART 2000 covered the entire field of fluiddynamics, from laminar flows in biological systems to astrophysical events, such as the explosion of a neutron star. The main exhibition by Dutch and Swiss artists showed video and related art under the title 'Walking on Air'. Experimental music was performed in two concerts.

It is true that "Nothing is more practical than theory" as Boltzmann said. Provided - however - that the assumptions on which The theory is founded are well understood. But. indeed. engineering costly experience shows that "Nothing can be more disastrous than a theory" when applied To a real task outside of practical limits of the assumptions made. Because of an homonymous identity with the considered problem. J.T.P The growing interest in Isodyne Stress Analysis and the related experience of the author show that the major monograph and reference book on the subject, Isodyne Stress Analysis by Jerzy T. Pindera and Marek-Jerzy Pindera, [27], does not of contain sufficiently detailed data on the theories and techniques experimentation. The purpose of this work is to close this gap. Thus, this work is an extension of Isodyne Stress Analysis and complementary to it. Consequently, only a short outline of the theory ofisodynes is given in Chapter 2. Only the basic concepts and relations are presented to provide the link between the underlying analytical and optical theories and the experimental techniques. One of the major purposes of a preface is to formulate and explain the chosen frame of reference in a condensed form, even when some components of it are discussed in the text. A main issue of the underlying frame of reference pertains to the roles of the abstract thinking and of the observation in cognition of reality.

This book describes in detail the current, state-of-the-art numerical treatment and simulation of multiphase flows in porous media. The porous media considered range from ordinary to fractured and deformable media, the models treated from single-phase compressible flow to multiphase multicomponent flow with mass interchange, while the computational algorithms encompass everything from classical iterative solvers to modern multigrid and domain decomposition approaches. Addressing many problems originating from the applied geosciences, the book focuses on their common mathematical and computational aspects. It will serve as an excellent research reference for all geoscientists, mathematicians, physicists, and engineers who work in the mathematical modeling and numerical simulation of multiphase flows in porous media.

The active field of multi-phase flow has undergone fundamental changes in the last decade. Many salient complex interfacial dynamics of such flows are now understood at a basic level with precise mathematical and quantitative characterization. This is quite a departure from the traditional empirical approach. At an IUTAM Symposium at Notre Dame, in 1999, some of the leading researchers in the field gathered to review the progress thus far and to contemplate future directions. Their reports are summarized in this Proceedings. Topics covered include solitary wave dynamics on viscous film flows, sheet formation and drop entrainment in stratified flow, wetting and dewetting dynamics, self-similar drop formation dynamics, waves in bubbly and suspension flow, and bubble dynamics. It is a unique and essential reference for applied mathematicians, physicists, research engineers, and graduate students to keep abreast of the latest theoretical and numerical developments that promise to transform multi-phase flow research.