Download or read book Numerical Simulation of Disperse Two phase Flows written by Thorsten Bosse and published by . This book was released on 2005 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical simulation of disperse two phase flows settling and break up of suspension drops particle settling in homogeneous turbulence written by Thorsten Bosse and published by . This book was released on 2005 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transport Phenomena in Dispersed Media written by G. I. Kelbaliyev and published by CRC Press. This book was released on 2019-09-26 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transport Phenomena in Dispersed Media addresses the main problems associated with the transfer of heat, mass and momentum. The authors focus on the analytical solutions of the mass and heat transfer equations; the theoretical problems of coalescence, coagulation, aggregation and fragmentation of dispersed particles; the rheology of structured aggregate and kinetically stable disperse systems; the precipitation of particles in a turbulent flow; the evolution of the distribution function; the stochastic counterpart of the mass transfer equations; the dissipation of energy in disperse systems; and many other problems that distinguish this book from existing publications. Key Selling Features Covers all technological processes taking place in the oil and gas complex, as well as in the petrochemical industry Presents new original solutions for calculating design as well as for the development and implementation of processes of chemical technology Organized to first provide an extensive review of each chapter topic, solve specific problems, and then review the solutions with the reader Contains complex mathematical expressions for practical calculations Compares results obtained on the basis of mathematical models with experimental data
Download or read book Direct Numerical Investigations of Dilute Dispersed Flows in Homogeneous Turbulence written by Aditya U. Karnik and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The motivation for the present work is to investigate particle-laden turbulent flows using accurate numerical simulations. In the present work, the carrier phase is modeled using direct numerical simulations (DNS) and the particles are tracked in a Lagrangian sense. Investigations of both one-way and two-way coupled particulate flows in homogeneous isotropic turbulence have been carried out. The phenomenon of interest in one-way coupled simulations is preferential accumulation, which refers to the tendency of heavy particles in isotropic turbulence to collect in regions of high strain and low vorticity. Several measures and mechanisms of accumulation have been reported in the literature often showing conflicting scaling with particle and fluid parameters. In the present study, accumulation has been quantified using several indicators to give a unified picture. The present work addresses the scaling of preferential accumulation with Reynolds number and suggests that while the spacing between particle clusters does exhibit a dependence on Reynolds number, the structure of particle clusters as viewed by individual particles shows little dependence on Reynolds number. The effect of adding a gravitational settling force on the particles has also been explored. While the gravity force tends to homogenize the particle distribution at low Stokes numbers, at high Stokes numbers it tends to arrange the originally random distribution into streaks in the direction of gravity. The ability of the Lorentz force to limit preferential accumulation has been the focus of the next part of the study. Charges are placed on particles to produce an electric field when the particles are inhomogeneously distributed. The electric field and thereby the Lorentz force tend to homogenize the particle distribution. It is interesting to note that the particle distribution attains a stationary state determined by the total amount of charge contained in the domain. It is demonstrated that in the presence of gravity, less amount of charge is required to homogenise particle distribution. Good agreement is observed for simulations of settling charged particles with experimental work. The modification of carrier phase turbulence by particles is studied formono-sized particles. The non-uniform modification of the fluid energy spectrum by particles has been demonstrated. It is seen that there is an increase in energy at high wave numbers for microparticles (St k
Download or read book Particles in Wall Bounded Turbulent Flows Deposition Re Suspension and Agglomeration written by Jean-Pierre Minier and published by Springer. This book was released on 2016-07-26 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents an up-to-date review of turbulent two-phase flows with the dispersed phase, with an emphasis on the dynamics in the near-wall region. New insights to the flow physics are provided by direct numerical simuation and by fine experimental techniques. Also included are models of particle dynamics in wall-bounded turbulent flows, and a description of particle surface interactions including muti-layer deposition and re-suspension.
Download or read book Theory and Modeling of Dispersed Multiphase Turbulent Reacting Flows written by Lixing Zhou and published by Butterworth-Heinemann. This book was released on 2018-01-25 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theory and Modeling of Dispersed Multiphase Turbulent Reacting Flows gives a systematic account of the fundamentals of multiphase flows, turbulent flows and combustion theory. It presents the latest advances of models and theories in the field of dispersed multiphase turbulent reacting flow, covering basic equations of multiphase turbulent reacting flows, modeling of turbulent flows, modeling of multiphase turbulent flows, modeling of turbulent combusting flows, and numerical methods for simulation of multiphase turbulent reacting flows, etc. The book is ideal for graduated students, researchers and engineers in many disciplines in power and mechanical engineering. Provides a combination of multiphase fluid dynamics, turbulence theory and combustion theory Covers physical phenomena, numerical modeling theory and methods, and their applications Presents applications in a wide range of engineering facilities, such as utility and industrial furnaces, gas-turbine and rocket engines, internal combustion engines, chemical reactors, and cyclone separators, etc.
Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Dispersed Multiphase Flows written by Balachandar, S. and published by Cambridge University Press. This book was released on 2024-03-07 with total page 1090 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Statistical Treatment of Turbulent Polydisperse Particle Systems written by J.S. Shrimpton and published by Springer. This book was released on 2014-06-20 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book we will introduce the modeling process of turbulent particulate flows which are encountered in many engineering and environmental applications. These types of flows usually also involve heat and mass transfer and turbulence adds another dimension to the complexity of the problem and hence a rigorous mathematical treatment is usually required. This required mathematical background makes the learning curve for new research students and practicing engineers extremely steep. Therefore modeling process for new or existing problems is extremely slow and is usually restricted to minor improvements to the to the available models. In this book we try to gather the required mathematical knowledge and introduce them more intuitively. Many numerical simulations of basic processes and equation will be given to provide the reader with a physical understanding of the different terms in the underlying equations. We will start the modeling process from a mesoscopic level which deals with the system of an intermediate length scale between the size of the atoms or molecules and the bulk of the material. This provides a unique opportunity for the reader to intuitively add different phenomena to their models and equipped with the necessary mathematical tools derive the final models for their problems.
Download or read book Multiphase Flows with Droplets and Particles Second Edition written by Clayton T. Crowe and published by CRC Press. This book was released on 2011-08-26 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the publication of the first edition of Multiphase Flow with Droplets and Particles, there have been significant advances in science and engineering applications of multiphase fluid flow. Maintaining the pedagogical approach that made the first edition so popular, this second edition provides a background in this important area of fluid mechanics to those new to the field and a resource to those actively involved in the design and development of multiphase systems. See what’s new in the Second Edition: Chapter on the latest developments in carrier-phase turbulence Extended chapter on numerical modeling that includes new formulations for turbulence and Reynolds stress models Review of the fundamental equations and the validity of the traditional "two-fluid" approach Expanded exercises and a solutions manual A quick look at the table of contents supplies a snapshot of the breadth and depth of coverage found in this completely revised and updated text. Suitable for a first-year graduate (5th year) course as well as a reference for engineers and scientists, the book is clearly written and provides an essential presentation of key topics in the study of gas-particle and gas-droplet flows.
Download or read book Multiphase Particulate Systems in Turbulent Flows written by Wioletta Podgórska and published by CRC Press. This book was released on 2019-09-17 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiphase Particulate Systems in Turbulent Flows: Fluid-Liquid and Solid-Liquid Dispersions provides methods necessary to analyze complex particulate systems and related phenomena including physical, chemical and mathematical description of fundamental processes influencing crystal size and shape, suspension rheology, interfacial area of drops and bubbles in extractors and bubble columns. Examples of mathematical model formulation for different processes taking place in such systems is shown. Discussing connections between turbulent mixing mechanisms and precipitation, it discusses influence of fine-scale structure of turbulence, including its intermittent character, on breakage of drops, bubbles, cells, plant cell aggregates. An important aspect of the mathematical modeling presented in the book is multi-fractal, taking into account the influence of internal intermittency on different phenomena. Key Features Provides detailed descriptions of dispersion processes in turbulent flow, interactions between dispersed entities, and continuous phase in a single volume Includes simulation models and validation experiments for liquid-liquid, gas-liquid, and solid-liquid dispersions in turbulent flows Helps reader learn formulation of mathematical models of breakage or aggregation processes using multifractal theory Explains how to solve different forms of population balance equations Presents a combination of theoretical and engineering approaches to particulate systems along with discussion of related diversity, with exercises and case studies
Download or read book Multiphase Flow Handbook written by Clayton T. Crowe and published by CRC Press. This book was released on 2005-09-19 with total page 1146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because of the importance of multiphase flows in a wide variety of industries, including power, petroleum, and numerous processing industries, an understanding of the behavior and underlying theoretical concepts of these systems is critical. Contributed by a team of prominent experts led by a specialist with more than thirty years of experience, the Multiphase Flow Handbook provides such an understanding, and much more. It covers all aspects of multiphase flows, from fundamentals to numerical methods and instrumentation. The book begins with an introduction to the fundamentals of particle/fluid/bubble interactions followed by gas/liquid flows and methods for calculating system parameters. It includes up-to-date information on practical industrial applications such as boiling and condensation, fluidized beds, aerosols, separation systems, pollution control, granular and porous media flow, pneumatic and slurry transport, and sprays. Coverage then turns to the most recent information on particle/droplet-fluid interactions, with a chapter devoted to microgravity and microscale flows and another on basic multiphase interactions. Rounding out the presentation, the authors discuss numerical methods, state-of-the art instrumentation, and advanced experimental techniques. Supplying up-to-date, authoritative information on all aspects of multiphase flows along with numerous problems and examples, the Multiphase Flow Handbook is the most complete reference available for understanding the flow of multiphase mixtures.
Download or read book Dispersion of Finite Size Droplets and Solid Particles in Isotropic Turbulence written by Michele Rosso and published by . This book was released on 2016 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent disperse two-phase flows, of either fluid/fluid or fluid/solid type, are common in natural phenomena and engineering devices. Notable examples are atmospheric clouds, i.e. dispersed liquid water droplets and ice particles in a complex turbulent flow, and spray of fuel droplets in the combustion chamber of internal combustion engines. However, the physics of the interaction between a dispersed phase and turbulence is not yet fully understood. The objective of this study is to compare the dispersion of deformable finite size droplets with that of solid particles in a turbulent flow in the absence of gravity, by performing Direct Numerical Simulation (DNS). The droplets and the particles have the same diameter, of the order of the Taylor's microscale of turbulence, and the same density ratio to the carrier flow. The solid particle-laden turbulence is simulated by coupling a standard projection method with the Immersed Boundary Method (IBM). The solid particles are fully resolved in space and time without considering particle/particle collisions (two-way coupling). The liquid droplet-laden turbulence is simulated by coupling a variable-density projection method with the Accurate Conservative Level Set Method (ACLSM). The effect of the surface tension is accounted for by using the Ghost Fluid Method (GFM) in order to avoid any numerical smearing, while the discontinuities in the viscous term of the Navier-Stokes equation are smoothed out via the Continuum Surface Force approach. Droplet/droplet interactions are allowed (four-way coupling). The results presented here show that in isotropic turbulence the dispersion of liquid droplets in a given direction is larger than that of solid particles due to the reduced decay rate of turbulence kinetic energy via the four-way coupling effects of the droplets.
Download or read book Particulate Two phase Flow written by M. C. Roco and published by Butterworth-Heinemann. This book was released on 1993 with total page 1032 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of 28 contributions on basic phenomena and advanced methods of investigation for particulate two-phase flow. Written by leading scientists in the field, this book covers new measurement methods, experimental results on particulate two-phase flow microstructure at low and large Reynolds numbers, micromechanical, probabilistic, and numerical simulations, as well as production of ultrafine particles via aerosols and colloids for materials with controlled microstructure. Each chapter is focused on the qualitative progress made in the field in the last several years and has an extensive review section and original results. This unique volume assembles information previously found only in journals and specialized publications. It is an invaluable reference for researchers and engineers from academia and industry.
Download or read book Numerical Simulation of Particulate Two phase Flow written by Neelesh Ashok Patankar and published by . This book was released on 1997 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Numerical Simulation of Droplet laden Isotropic Turbulence written by Michael S. Dodd and published by . This book was released on 2017 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interaction of liquid droplets with turbulence is important in numerous applications ranging from rain formation to oil spills to spray combustion. The physical mechanisms of droplet-turbulence interaction are largely unknown, especially when compared to that of solid particles. Compared to solid particles, droplets can deform, break up, coalesce and have internal fluid circulation. The main goal of this work is to investigate using direct numerical simulation (DNS) the physical mechanisms of droplet-turbulence interaction, both for non-evaporating and evaporating droplets. To achieve this objective, we develop and couple a new pressure-correction method with the volume-of-fluid (VoF) method for simulating incompressible two-fluid flows. The method's main advantage is that the variable coefficient Poisson equation that arises in solving the incompressible Navier-Stokes equations for two-fluid flows is reduced to a constant coefficient equation. This equation can then be solved directly using, e.g., the FFT-based parallel Poisson solver. For a $1024^3$ mesh, our new pressure-correction method using a fast Poisson solver is ten to forty times faster than the standard pressure-correction method using multigrid. Using the coupled pressure-correction and VoF method, we perform direct numerical simulations (DNS) of 3130 finite-size, non-evaporating droplets of diameter approximately equal to the Taylor lengthscale and with 5~\% droplet volume fraction in decaying isotropic turbulence at initial Taylor-scale Reynolds number $\Rey_\lambda=83$. In the droplet-laden cases, we vary one of the following three parameters: the droplet Weber number based on the r.m.s. velocity of turbulence ($0.1 \leq \Webrms \leq 5$), the droplet- to carrier-fluid density ratio ($1 \leq \rho_d/\rho_c \leq 100$) or the droplet- to carrier-fluid viscosity ratio ($1 \leq \mu_d/\mu_c \leq 100$). We derive the turbulence kinetic energy (TKE) equations for the two-fluid, carrier-fluid and droplet-fluid flow. These equations allow us to explain the pathways for TKE exchange between the carrier turbulent flow and the flow inside the droplet. We also explain the role of the interfacial surface energy in the two-fluid TKE equation through work performed by surface tension. Furthermore, we derive the relationship between the power of surface tension and the rate of change of total droplet surface area. This link allows us to explain how droplet deformation, breakup and coalescence play roles in the temporal evolution of TKE. We then extend the code for non-evaporating droplets and develop a combined VoF method and low-Mach-number approach to simulate evaporating and condensing droplets. The two main novelties of the method are: (i) the VOF algorithm captures the motion of the liquid gas interface in the presence of mass transfer due to evaporation and condensation without requiring a projection step for the liquid velocity, and (ii) the low-Mach-number approach allows for local volume changes caused by phase change while the total volume of the liquid-gas system is constant. The method is verified against an analytical solution for a Stefan flow problem, and the $D^2$ law is verified for a single droplet in quiescent gas. Finally, we perform DNS of an evaporating liquid droplet in forced isotropic turbulence. We show that the method accurately captures the temperature and vapor fields in the turbulent regime, and that the local evaporation rate can vary along the droplet surface depending on the structure of the surrounding vapor cloud. We also report the time evolution of the mean Sherwood number, which indicates that turbulence enhances the vaporization rate of liquid droplets.
Download or read book Multiphase Flow Handbook Second Edition written by Efstathios Michaelides and published by CRC Press. This book was released on 2016-10-26 with total page 1559 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Multiphase Flow Handbook, Second Edition is a thoroughly updated and reorganized revision of the late Clayton Crowe’s work, and provides a detailed look at the basic concepts and the wide range of applications in this important area of thermal/fluids engineering. Revised by the new editors, Efstathios E. (Stathis) Michaelides and John D. Schwarzkopf, the new Second Edition begins with two chapters covering fundamental concepts and methods that pertain to all the types and applications of multiphase flow. The remaining chapters cover the applications and engineering systems that are relevant to all the types of multiphase flow and heat transfer. The twenty-one chapters and several sections of the book include the basic science as well as the contemporary engineering and technological applications of multiphase flow in a comprehensive way that is easy to follow and be understood. The editors created a common set of nomenclature that is used throughout the book, allowing readers to easily compare fundamental theory with currently developing concepts and applications. With contributed chapters from sixty-two leading experts around the world, the Multiphase Flow Handbook, Second Edition is an essential reference for all researchers, academics and engineers working with complex thermal and fluid systems.
