Fluid Mechanics at Interfaces 1: Methods and Diversity

Description

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. Cover Half-Title Page Title Page Copyright Page Contents Preface 1. Modeling Interfaces with Fluid Phase List of symbols 1.1. The concept of an interface 1.1.1. Interface in physics and geometric surfaces 1.1.2. The concept of equilibrium in the domain of interfaces 1.2. Some examples of interfaces 1.2.1. Fluid phase change and separation interface 1.2.2. Solidification interface 1.2.3. Generalized interfaces 1.3. Mathematical description of an interfacial layer 1.3.1. Normal gradient and tangential gradient 1.3.2. Structure and kinematics of an interfacial layer 1.3.3. Bulk and surface quantities 1.3.4. Interface balances 1.3.5. Constitutive laws 1.4. Some additional information and examples of application 1.4.1. Effective surface tension between two miscible liquids 1.4.2. Terms that come into play in interface balance laws 1.4.3. Normal shockwave 1.4.4. Combustion waves 1.4.5. Thin premixed flame 1.4.6. Boundary layers 1.5. Conclusion 1.6. References Further references 2. Simulations of Turbulent Two-Phase Flows with Phase Change Using a Multifield Approach Combined with LES List of symbols 2.1. Introduction 2.2. Computational model 2.2.1. Two-fluid model 2.2.2. Large Bubble Model 2.3. Filtered two-fluid equations 2.4. A priori LES study 2.4.1. Presentation of the test case 2.4.2. Order of magnitude of the subgrid terms 2.4.3. Comparison of turbulence models 2.4.4. ADM order 2.4.5. Effect of the filter 2.5. Comparison of turbulence models with true LES 2.5.1. Presentation of the METERO experiment 2.5.2. Presentation of the test case 2.5.3. Simulation results 2.5.4. Comparison between RANS and LES 2.5.5. ADM implementation 2.6. New phase change model for large interfaces 2.6.1. Implementation of the new heat flux model 2.6.2. Validation of the new heat transfer model 2.6.3. Sucking problem 2.6.4. Stefan problem 2.7. Conclusion 2.8. References 3. An Original Approach to Extract Momentumand Heat Transfers from Particle-Resolved Simulations ofParticulate Flows 3.1. Introduction 3.2. Numerical methodology 3.2.1. Viscous penalty method 3.2.2. Drag force and heat flux computation using Aslam extension 3.3. Isolated stationary sphere passed by a uniform flow 3.3.1. Drag force computation 3.3.2. Heat transfer computation 3.4. Face-centered cubic arrangement of stationary sphere passed by a uniform flow 3.4.1. Monodispersed face-centered cubic periodic arrangement of spheres 3.4.2. Bidisperse face-centered cubic periodic arrangement of spheres 3.5. Conclusion 3.6. Acknowledgments 3.7. References 4. Interfaces and Critical Fluids List of symbols 4.1. Thermostatics of fluids in the vicinity of the critical point 4.1.1. Real fluids 4.1.2. A van der Waals fluid 4.1.3. Other laws for gases and dense liquids 4.2. Thermodynamics of fluids in the vicinity of the critical point 4.2.1. Universal exponents 4.2.2. Isobaric evolutions 4.2.3. Valid expressions of varying distance from the critical point 4.2.4. Summary of theoretical approaches 4.3. A specific mode of heat transmission: the piston effect 4.4. Expansion of a “drop” at critical pressure 4.5. Behavior of a pocket of supercritical fluid immersed into a high-temperature environment 4.6. Boiling near the critical point2 4.7. Conclusion 4.8. References 5. Shear-Induced Anomalies in the Brownian Motion of Particles in Strongly Fluctuating Near-Critical Mixtures 5.1. Introduction 5.2. Theoretical background 5.2.1. Miscibility critical point in binary mixtures 5.2.2. Effect of shear flow 5.2.3. Colloid Brownian motion and shear flow 5.3. Experiments and methods 5.4. Results and discussion 5.5. Concluding remarks 5.6. Acknowledgements 5.7. Appendix: Light scattering (photon beating spectroscopy) 5.8. References 6. Basics on Interfaces in Combustion List of symbols 6.1. Introduction 6.2. Non-premixed laminar combustion 6.2.1. Overview of a candle flame 6.2.2. Analytical solution of a diffusion flame: the Burke–Schumann problem 6.2.3. Numerical solutions 6.3. Turbulent non-premixed combustion 6.4. Premixed combustion 6.4.1. Propagation of a premixed flame 6.4.2. The combustion rate of the adiabatic, planar premixed flame 6.4.3. Concepts in turbulent premixed combustion 6.5. Plate combustion 6.6. Powders 6.6.1. Thermites 6.6.2. Solid propellant rockets 6.6.3. Spin-like combustion 6.7. Sprays and fireworks 6.8. Conclusion 6.9. Acknowledgments 6.10. Appendices 6.10.1. Appendix A: The Rankine–Hugoniot theory 6.10.2. Appendix B: Historical overview of research on combustion 6.11. References List of Authors Index Summary of Volume 2 Other titles from iSTE in Fluid Mechanics