Mechanical And Thermodynamical Modeling Of Fluid Interfaces

This book constitutes a comprehensive survey of the balance equations for mass, momentum and energy for the interfaces in pure fluids and mixtures. Constitutive laws are presented for many situations in engineering science, and examples are provided, including surface viscosity effects, variable surface tension and vapor recoil. In addition, some extensions of existing theory are given: stretch effect in premixed flames, relaxation zones downstream two-phase shock waves, and effective surface tension for steep gradient zones. Contents: Thermodynamics and Kinematics of Interfaces; Interface Balance Laws; Constitutive Relations Deduced from Linear Irrevesible Thermodynamics for the Two-Dimensional Interfaces; Classical Three-Dimensional Constitutive Relations Deduced from Linear Irreversible Thermodynamics and Their Consequences for Interfaces; Second Gradient Theory Applied to Interfacial Medium; Typical Problems Involving Surface Tensions and Other Surface Properties. Readership: Graduates, physicists, applied mathematicians and engineers seeking classical knowledge in continuum mechanics and thermodynamics, especially in the thermodynamics of irreversible processes.

This book constitutes a comprehensive survey of the balance equations for mass, momentum and energy for the interfaces in pure fluids and mixtures. Constitutive laws are presented for many situations in engineering science, and examples are provided, including surface viscosity effects, variable surface tension and vapor recoil. In addition, some extensions of existing theory are given: stretch effect in premixed flames, relaxation zones downstream two-phase shock waves, and effective surface tension for high gradient zones.

This third volume describes continuous bodies treated as classical (Boltzmann) and spin (Cosserat) continua or fluid mixtures of such bodies. It discusses systems such as Boltzmann continua (with trivial angular momentum) and Cosserat continua (with nontrivial spin balance) and formulates the balance law and deformation measures for these including multiphase complexities. Thermodynamics is treated in the spirit of Müller–Liu: it is applied to Boltzmann-type fluids in three dimensions that interact with neighboring fluids on two-dimensional contact surfaces and/or one-dimensional contact lines. For all these situations it formulates the balance laws for mass, momenta, energy, and entropy. Further, it introduces constitutive modeling for 3-, 2-, 3-d body parts for general processes and materially objective variable sets and their reduction to equilibrium and non-equilibrium forms. Typical (reduced) fluid spin continua are liquid crystals. Prominent nematic examples of these include the Ericksen–Leslie–Parodi (ELP) formulation, in which material particles are equipped with material unit vectors (directors). Nematic liquid crystals with tensorial order parameters of rank 1 to n model substructure behavior better, and for both classes of these, the book analyzes the thermodynamic conditions of consistency. Granular solid–fluid mixtures are generally modeled by complementing the Boltzmann laws with a balance of fluctuation (kinetic) energy of the particles. The book closes by presenting a full Reynolds averaging procedure that accounts for higher correlation terms e.g. a k-epsilon formulation in classical turbulence. However, because the volume fraction is an additional variable, the theory also incorporates ‘k-epsilon equations’ for the volume fraction.

Interfaces are present in most fluid mechanics problems. They not only denote phase separations and boundary conditions, but also thin flames and discontinuity waves. Fluid Mechanics at Interfaces 1 focuses on the science of interfaces, in particular, using various scientific methods of analysis relating to space, speed and time. Our investigation takes us from the microscopic or small scale (starting with molecular and nanoscopic scales) to the macroscopic (including meso and interstellar scales), and also explores the laws of interfaces (classical mechanics, quantum mechanics and relativistic mechanics). Chapter 1 examines the questions raised by modeling interfaces in the presence of one or more fluid phases. Chapter 2 discusses the action of turbulence in liquid–vapor flows that contain both small, dispersed bubbles as well as large bubbles, with heat exchanges at the interfaces. In addition, a new model is presented, using large eddy simulation (LES). Chapter 3 studies an original method for calculating the drag force and thermal transfers in flows around networks of spherical particles, while Chapter 4 focuses on the relationships between interfaces and critical fluids. Chapter 5 examines shearing, which causes anomalies in the Brownian motion of particles in strongly fluctuating near-critical mixtures, and Chapter 6 introduces basic concepts related to combustion interfaces, raising the question of the combustion of solids, before ending with a brief presentation of the Rankine–Hugoniot theory and a historical overview of the research carried out in the field of combustion.

The aim of this book is to relate fluid flows to chemical reactions. It focuses on the establishment of consistent systems of equations with their boundary conditions and interfaces, which allow us to model and deal with complex situations. Chapter 1 is devoted to simple fluids, i.e. to a single chemical constituent. The basic principles of incompressible and compressible fluid mechanics, are presented in the most concise and educational manner possible, for perfect or dissipative fluids. Chapter 2 relates to the flows of fluid mixtures in the presence of chemical reactions. Chapter 3 is concerned with interfaces and lines. Interfaces have been the subject of numerous publications and books for nearly half a century. Lines and curvilinear media are less known Several appendices on mathematical notation, thermodynamics and mechanics methods are grouped together in Chapter 4. This summary presentation of the basic equations of simple fluids, with exercises and their solutions, as well as those of chemically reacting flows, and interfaces and lines will be very useful for graduate students, engineers, teachers and scientific researchers in many domains of science and industry who wish to investigate problems of reactive flows. Portions of the text may be used in courses or seminars on fluid mechanics.

The modeling of reactive flows has progressed mainly with advances in aerospace, which gave birth to a new science called aerothermochemistry, as well as through developments in chemical and process engineering. This work examines basic concepts and methods necessary to study reactive flows and transfer phenomena in areas such as fluid mechanics, thermodynamics, and chemistry. The book presents tools of interest to graduate students, researchers in mathematical physics, and engineers who wish to investigate problems of reactive flows. Portions of the text may be used in courses on the physics of liquids or in seminars on mechanics.

Interfacial Fluid Mechanics: A Mathematical Modeling Approach provides an introduction to mathematical models of viscous flow used in rapidly developing fields of microfluidics and microscale heat transfer. The basic physical effects are first introduced in the context of simple configurations and their relative importance in typical microscale applications is discussed. Then, several configurations of importance to microfluidics, most notably thin films/droplets on substrates and confined bubbles, are discussed in detail. Topics from current research on electrokinetic phenomena, liquid flow near structured solid surfaces,evaporation/condensation, and surfactant phenomena are discussed in the later chapters.

In this book fluid mechanics and thermodynamics (F&T) are approached as interwoven, not disjoint fields. The book starts by analyzing the creeping motion around spheres at rest: Stokes flows, the Oseen correction and the Lagerstrom-Kaplun expansion theories are presented, as is the homotopy analysis. 3D creeping flows and rapid granular avalanches are treated in the context of the shallow flow approximation, and it is demonstrated that uniqueness and stability deliver a natural transition to turbulence modeling at the zero, first order closure level. The difference-quotient turbulence model (DQTM) closure scheme reveals the importance of the turbulent closure schemes’ non-locality effects. Thermodynamics is presented in the form of the first and second laws, and irreversibility is expressed in terms of an entropy balance. Explicit expressions for constitutive postulates are in conformity with the dissipation inequality. Gas dynamics offer a first application of combined F&T. The book is rounded out by a chapter on dimensional analysis, similitude, and physical experiments.