Differential equations, especially nonlinear, present the most effective way for describing complex physical processes. Methods for constructing exact solutions of differential equations play an important role in applied mathematics and mechanics. This book aims to provide scientists, engineers and students with an easy-to-follow, but comprehensive, description of the methods for constructing exact solutions of differential equations.

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 any number of applications for information regarding transition location and the details of the subsequent turbulent flow. The JUT AM Symposium on Laminar-Turbulent Transition, co-hosted by Arizona State University and the University of Arizona, was held in Sedona, Arizona. Although four previous JUT AM Symposia bear the same appellation (Stuttgart 1979, Novosibirsk 1984, Toulouse 1989, and Sendai 1994) the topics that were emphasized at each were different and reflect the evolving nature of our understanding of the transition process. The major contributions of Stuttgart 1979 centered on nonlinear behavior and later stages of transition in two-dimensional boundary layers. Stability of closed systems was also included with Taylor vortices in different geometries. The topics of Novosibirsk 1984 shifted to resonant wave interactions and secondary instabilities in boundary layers. Pipe- and channel-flow transition were discussed as model problems for the boundary layer. Investigations of free shear layers were presented and a heavy dose of supersonic papers appeared for the first time. The character of Toulouse 1989 was also different in that 3-D boundary layers, numerical simulations, streamwise vortices, and foundation papers on receptivity were presented. Sendai 1994 saw a number of papers on swept wings and 3-D boundary layers. Numerical simulations attacked a broader range of problems.

This book is devoted to recent developments in the field of rotating fluids, in particular the study of Taylor--Couette flow, spherical Couette flow, planar Couette flow, as well as rotating annulus flow. Besides a comprehensive overview of the current state of the art, possible future directions in this research field are investigated. The first part of this volume presents several new results in the classical Taylor--Couette system covering diverse theoretical, experimental and numerical work on bifurcation theory, influence of boundary conditions, counter-rotating flows, spiral vortices and many others. The second part focuses on spherical Couette flows, including isothermal flows, thermal convective motion, as well as magnetohydrodynamics in spherical shells. The remaining parts are devoted to Goertler vortices, rotating annulus flows, as well as superfluid Couette flows. The present book will be of interest to all researchers and graduate students working actively in the field.

The subject of wave phenomena is well-known for its inter-disciplinary nature. Progress in this field has been made both through the desire to solve very practical problems, arising in acoustics, optics, radiophysics, electronics, oceanography, me teorology and so on, and through the development of mathematical physics which emphasized that completely different physical phenomena are governed by the same (or similar) equations. In the immense literature on physics of waves there is no lack of good presentations of particular branches or general textbooks on mathematical physics. But if one restricts the attention to pulse propagation phenomena, one no tices that many useful facts are scattered among the various books and journals, and their connections are not immediately apparent. For example, the problems involv ing acoustic pulse propagation in bubbly liquids and those related to electromagnetic pulses in resonant media are usually treated without much cross reference in spite of their obvious connections. The authors of this book have attempted to write a coherent account of a few pulse propagation problems selected from different branches of applied physics. Although the basic material on linear pulse propagation is included, some topics have their own unique twists, and a comprehensive treatment of this body of material can hardly be found in other sources. First of all, the problem of pulse propagation in non equilibrium media (unstable or admitting attenuation) is far more delicate than it is apparent at a first glance."

The survival of the Aeronautical Industries of Europe in the highly competitive World Aviation Market is strongly dependent on such factors as time-to-market of a new or derivative aircraft and on its manufacturing costs but also on the achievement of a competitive technological advantage by which an increased market share can be gained. Recognizing this, cooperative research is continuously encouraged and co-financed by the European Union in order to strengthen the scientific and technological base of the Aeronautical Industries thus providing - among others - the technological edge needed for survival. Corresponding targets of research within Area 3, Technologies for Transport Means, and here in particular Area 3A, Aeronautics Technologies, of the Industrial and Materials Technologies Program ( Brite -EuRam III, 1994 -1998) have been identified to be aircraft efficiency, cost effectiveness and environmental impact. Concerning aircraft efficiency - relevant to the present research - a reduction in aircraft drag of 10%, a reduction in aircraft fuel consumption of 30%, and a reduction in airframe, engine and system weight of 20% are envisaged. Meeting these objectives has, of course, also a strong positive impact on the environment.

The need to predict, understand, and optimize complex physical and c- mical processes occurring in and around the earth, such as groundwater c- tamination, oil reservoir production, discovering new oil reserves, and ocean hydrodynamics, has been increasingly recognized. Despite their seemingly disparate natures, these geoscience problems have many common mathe- tical and computational characteristics. The techniques used to describe and study them are applicable across a broad range of areas. The study of the above problems through physical experiments, mat- matical theory, and computational techniques requires interdisciplinary col- boration between engineers, mathematicians, computational scientists, and other researchers working in industry, government laboratories, and univ- sities. By bringing together such researchers, meaningful progress can be made in predicting, understanding, and optimizing physical and chemical processes. The International Workshop on Fluid Flow and Transport in Porous - dia was successfully held in Beijing, China, August 2{6, 1999. The aim of this workshop was to bring together applied mathematicians, computational scientists, and engineers working actively in the mathematical and nume- cal treatment of ?uid ?ow and transport in porous media. A broad range of researchers presented papers and discussed both problems and current, state-of-the-art techniques.

This volume contains the proceedings of the CEASlDragNet European Drag Reduction Conference held on 19-21 June 2000 in Potsdam, Germany. This conference, succeeding the First and Second European Forum on Laminar Flow Technology 1992 and 1996 respectively, was initiated by the European Drag Reduction Network (DragNet) and organised by DGLR (Deutsche Gesellschaft fUr Luft- und Raumfahrt - Lilienthal Oberth e. V. ) under the auspices ofCEAS (Confederation of European Aerospace Societies). The development of aerodynamic drag reduction technologies is driven by predictions of remarkable fuel savings, promising substantial improvements not only of aircraft efficiency but also of environmental compatibility. However, considerable efforts on an European scale are needed in order to develop, qualifY and demonstrate the means for their practical realisation. The primary aim of this conference was to provide a comprehensive survey of the current status of research, development and application in all disciplines of aerodynamic drag re- duction including laminar flow technology, adaptive wing concepts, turbulence and se- paration control, induced drag reduction and supersonic flow aspects. Besides aerodynamic topics the Call for Papers addressed also interdisciplinary aspects of design & system inte- gration, structures, materials, manufacturing, operations and maintenance. The Programme Committee (PC), responsible for the scientific preparation of the conference, consisted of CEAS representatives and DragNet board members (see following page).

Results of experimental research on aerodynamic and acoustic control of subsonic turbulent jets by acoustic excitation are presented. It was demonstrated that these control methods, originated by authors, not only can intensify mixing (by acoustic irradiation at low frequency), but also notably ease it (at high-frequency irradiation). This research monograph presents the updated results of the authors supplemented by other investigations conducted in USA, Germany and Great Britain. The methods for the numerical simulation of subsonic turbulent jets under acoustic excitation are described in detail, and examples are reviewed of practical applications, including reduction of turbojet engine noise and acoustic control of self-sustained oscillations in wind tunnels.

This well-written book explains the theory of spectral methods and their application to the computation of viscous incompressible fluid flows in clear and elementary terms. It begins with an introduction to the fundamentals of spectral methods and then moves on to cover, in particular, the Fourier and Chebyshev methods. Examples are included. Chapters 6 and 7 handle streamfunction-vorticity and velocity-pressure fomulations of the Navier-Stokes equations. Chapter 8 and 9 address special topics such as self- adaptive coordinate transform, treatment of singularities, and domain decomposition. The work will be useful to those teaching in the field at the graduate level, as well as to researchers working in the area.

Experts in rheology and polymer processing present up-to-date, fundamental and applied information on the rheological properties of polymers, in particular those relevant to processing, contributing to the physical understanding and the mathematical modelling of polymer processing sequences. Basic concepts of non-Newtonian fluid mechanics, micro-rheological modelling and constitutive modelling are reviewed, and rheological measurements are described. Topics with practical relevance are debated, such as linear viscoelasticity, converging and diverging flows, and the rheology of multiphase systems. Approximation methods are discussed for the computer modelling of polymer melt flow. Subsequently, polymer processing technologies are studied from both simulation and engineering perspectives. Mixing, crystallization and reactive processing aspects are also included. Audience: An integrated and complete view of polymer processing and rheology, important to institutions and individuals engaged in the characterisation, testing, compounding, modification and processing of polymeric materials. Can also support academic polymer processing engineering programs.

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 book provides a broad overview of the full spectrum of state-of-the-art computational activities in multiphase flow as presented by top practitioners in the field. It starts with well-established approaches and builds up to newer methods. These methods are illustrated with applications to a broad spectrum of problems involving particle dispersion and deposition, turbulence modulation, environmental flows, fluidized beds, bubbly flows, and many others.

The Origin of Species Charles Darwin The origin of turbulence in fluids is a long-standing problem and has been the focus of research for decades due to its great importance in a variety of engineering applications. Furthermore, the study of the origin of turbulence is part of the fundamental physical problem of turbulence description and the philosophical problem of determinism and chaos. At the end of the nineteenth century, Reynolds and Rayleigh conjectured that the reason of the transition of laminar flow to the 'sinuous' state is in stability which results in amplification of wavy disturbances and breakdown of the laminar regime. Heisenberg (1924) was the founder of linear hydrody namic stability theory. The first calculations of boundary layer stability were fulfilled in pioneer works of Tollmien (1929) and Schlichting (1932, 1933). Later Taylor (1936) hypothesized that the transition to turbulence is initi ated by free-stream oscillations inducing local separations near wall. Up to the 1940s, skepticism of the stability theory predominated, in particular due to the experimental results of Dryden (1934, 1936). Only the experiments of Schubauer and Skramstad (1948) revealed the determining role of insta bility waves in the transition. Now it is well established that the transition to turbulence in shear flows at small and moderate levels of environmental disturbances occurs through development of instability waves in the initial laminar flow. In Chapter 1 we start with the fundamentals of stability theory, employing results of the early studies and recent advances."

This volume contains 27 contributions to the Second Russian-German Advanced Research Workshop on Computational Science and High Performance Computing presented in March 2005 at Stuttgart, Germany. Contributions range from computer science, mathematics and high performance computing to applications in mechanical and aerospace engineering.

Capillary Forces in Microassembly discusses the use of capillary forces as a gripping principle in microscale assembly. Clearly written and well-organized, this text brings together physical concepts at the microscale with practical applications in micromanipulation. Throughout this work, the reader will find a review of the existing gripping principles, elements to model capillary forces as well as descriptions of the simulation and experimental test bench developed to study the design parameters. Using well-known concepts from surface science (such as surface tension, capillary effects, wettability, and contact angles) as inputs to mechanical models, the amount of effort required to handle micro-components is then predicted.

Researchers and engineers involved in micromanipulation and precision assembly will find this a highly useful reference for microassembly system design and analysis.

Hyposonic fluid flows, characterized by a low Mach number, are mainly linked with geophysical and environmental fluid flows. In addition they are relevant to engineers because of their connection with aerodynamics. The books brings together insights derived from mathematically rigorous results and combines them with a number of realistic fluid flow situations. Asymptotic analytic solutions for the low-Mach number cases are developed to provide both insights into the underlying physics as well as benchmarks for numerical computations.

This volume contains contributions to the First Kazakh-German Advanced Research Workshop on Computational Science and High Performance Computing presented in September 2005 at Almaty, Kazakhstan. The workshop was organized by the High Performance Computing Center Stuttgart (Stuttgart, Germany), al-Farabi Kazakh National University (Almaty, Kazakhstan) and the Institute of Computational Technologies SB RAS (Novosibirsk, Russia) in the framework of activities of the German-Russian Center for Computational Technologies and High Performance

The importance of mathematics in the study of problems arising from the real world, and the increasing success with which it has been used to model situations ranging from the purely deterministic to the stochastic, is well established. The purpose of the set of volumes to which the present one belongs is to make available authoritative, up to date, and self-contained accounts of some of the most important and useful of these analytical approaches and techniques. Each volume provides a detailed introduction to a specific subject area of current importance that is summarized below, and then goes beyond this by reviewing recent contributions, and so serving as a valuable reference source. The progress in applicable mathematics has been brought about by the extension and development of many important analytical approaches and techniques, in areas both old and new, frequently aided by the use of computers without which the solution of realistic problems would otherwise have been impossible.

This textbook discusses the fundamental principles of sediment transport in the geophysical context of rivers and is intended as both a course textbook and as a guide for the practical engineer. We begin by describing phenomena such as bed load and suspension transport from a classical perspective by applying the mean wall shear stress approach while additionally incorporating a statistical description of the inherent wall shear stress fluctuations. Concepts from turbulent flow regime are introduced to address the limitations of the classical approach to various aspects of sediment transport, such as for example, the Newtonian description of dense suspensions, or the description of the self-organization processes for developing bed forms, or the prediction of transport in very rough bed conditions. In this context coherent structures and flow separation mechanisms are developed as important new elements, which allow using topological rules for the formulation of transport especially for developing bed forms. Since the most up-to-date research findings in the field are presented, this book serves as both a support in the formulation of academic research programs, and as a practical text for engineers seeking to simulate complex problems or special aspects of sediment transport. This book will therefore be of interest and of use to both students and to the professional scientist.

First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering

From the foreword to the third edition written by Charles Meneveau: ..". this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."

This volume contains the contributions to the 10th DGLR I AG ST AB-Symposium held at the German Aerospace Research Establishment (DLR) -Braunschweig Research Centre - November, 11 to 13, 1996. AG STAB is the German Aerospace AerodynapIics Association, founded at the end of the 70', while DGLR is the German Society for Aeronautics and Astronautics (Deutsche Gesellschaft fur Luft- und Raumfahrt, LilienthaI Oberth Gesellschaft). In the AG STAB German scientists and engineers from universities, research-establishments and industries are involved, who are doing research and project work in numerical and experimental fluidmechanics and aerodynamics for aerospace and other applications. About 20 years ago it became obvious for this community that a joint effort of members of universities, the DLR and industry was necessary to counter-act declining budgets in the field. It was decided to approach high-level persons in industry, ministries and the parliament for help to shift the trend with its negative effects for research and industry. From the begin it was clear that an effort should be built around a central theme. ''Flow with Separation" became the topic of the AG STAB (Arbeitsgemeinschaft Stromung mit Ablosung), which developed fast into a lively association, with, however, a larger scope than just flow with separation."

This book contains lecture notes and invited contributions presented at the NATO Advanced Study Institute and EPS Liquid State Conference on PHYSICOCHEMICAL HYDRODYNAMICS-PCH: INTERFACIAL PHENOMENA that were held July 1-15, 1986, in LA RABIDA (Huelva) SPAIN. Although we are aware of the difficulty in organizing the contents due to the broad and multidisciplinary aspects of PCH-Interfacial Phenomena, we have tried to accomodate papers by topics and have not followed the order in the presentation at the meetings. There is also no distinction between the ASI notes and Conference papers. We have done our best to offer a coverage as complete as possible of the field. However, we had difficulties coming from the fact that some authors were so busy that either did not find time to submit their contribution or did not have time to write a comprehensive paper. We also had to cope with very late arrivals, postdeadline valuable contributions that we felt had to be included here. Our gratitude goes to the NATO Scientific Affairs Division for its economic support and to the EPS Liquid State Committee for its sponsorship. Financial support also came from Asociacion Industrias Quimicas-Huelva (Spain), Caycit-Ministerio De Educacion Y Ciencia (Spain), Canon-Espana (Spain), Citibank-Espana (Spain), CNLS-Los Alamos Nat. Lab. (U. S. A. ), CSIC (Spain), EPS, ERT (Spain), ESA, Fotonica (Spain), IBM-Espana (Spain), Junta De Andalucia (Spain), NATO, NSF (U. S. A. ), ONR-London (U. S. A.

Ideals are simple and able to be easily understood, but never exist in reality. In this book a theory based on the second law of thermodynamics and its applications are described. In thermodynamics there is a concept of an ideal gas which satisfies a mathematical formula PV = RT. This formula can appro- mately be applied to the real gas, so far as the gas has not an especially high pressure and low temperature. In connection with the second law of thermo- namics there is also a concept of reversible and irreversible processes. The reversible process is a phenomenon proceeding at an infinitely low velocity, while the irreversible process is that proceeding with a finite velocity. Such a process with an infinitely slow velocity can really never take place, and all processes observed are always irreversible, therefore, the reversible process is an ideal process, while the irreversible process is a real process. According to the first law of thermodynamics the energy increase dU of the thermodynamic system is a sum of the heat dQ added to the system and work dW done in the system. Practically, however, the mathematical formula of the law is often expressed by the equation , or some similar equations derived from this formula, is applied to many phenomena. Such formulae are, however, th- retically only applicable to phenomena proceeding at an infinitely low velocity, that is, reversible processes or ideal processes.

Combustion systems are confined fields of compressible fluids where exothermic processes of combustion take place, subject to boundary conditions imposed at its borders. The subject of Dynamics of Combustion Systems is presented in three parts:

Part 1. Exothermicity considering the thermodynamic effects due to evolution of exothermic energy in a combustion system

Chapter 1. Thermodynamic Aspects
Chapter 2. Evolutionary Aspects
Chapter 3. Heat Transfer Aspects
Chapter 4. Chemical Kinetic Aspects

Part 2. Field exposing the dynamic properties of flow fields where the exothermic energy is deposited

Chapter 5. Aerodynamic Aspects
Chapter 6. Random Vortex Method
Chapter 7. Gasdynamic Aspects
Chapter 8. Gasdynamic Fronts

Part 3. Explosions revealing the dynamic features of fields and fronts due to rapid deposition of exothermic energy

Chapter 9. Blast Wave Theory
Chapter 10. Self-Similar Solution
Chapter 11. Phase Space Method
Chapter 12. Detonation

Fluid Mechanics, as a scientific discipline in a modern sense, was established between the last third of the 17th century and the first half of the 18th century. This book analyses its genesis from two lines: resistance and discharge. This approach highlights the existence of a remarkable experimental aspect in the aforementioned research lines, together with their link with problems of a practical nature, such as ballistics, hydraulics, fluid-using machines or naval theory.