Download or read book A Study of Taylor Bubbles in Vertical and Inclined Slug Flow Using Multiphase CFD with Level Set written by Enrique Lizarraga-García and published by . This book was released on 2016 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Slug flow commonly occurs in gas and oil systems. Current predictive methods are based on mechanistic models, which require the use of closure relations to complement the conservation equations to predict integral flow parameters such as liquid holdup (or void fraction) and pressure gradient. These closure relations are typically developed either empirically or from semi-empirical models assuming idealized geometry of the interface, thus they carry the highest uncertainties in the mechanistic models. In this work, sensitivity analysis has determined that Taylor bubble velocity in slug flow is one such closure relation which significantly affects the calculation of these parameters. The main objective is to develop a unified higher-fidelity closure relation for Taylor bubble velocity. Here, we employ a novel approach to overcome the experimental limitations: validated 3D Computational Multiphase Fluid Dynamics (CMFD) with Interface Tracking Methods (ITMs) where the interface is tracked with a Level-Set method implemented in the commercial code TransAT®. In the literature, the Taylor bubble velocity is modeled based on two different contributions: (i) the drift velocity, i.e., the velocity of propagation of a Taylor bubble in stagnant liquid, and (ii) the liquid flow contribution. Here, we first analyze the dynamics of Taylor bubbles in stagnant liquid by generating a large numerical database that covers the most ample range of fluid properties and pipe inclination angles explored to date (Eo [epsilon] [10, 700], Mo [epsilon] [1 . 10-6, 5 . 103], and [theta] [epsilon] [0°, 90°]). A unified Taylor bubble velocity correlation, proposed for use as a slug flow closure relation in the mechanistic model, is derived from that database. The new correlation predicts the numerical database with 8.6% absolute average relative error and a coefficient of determination R2 = 0.97, and other available experimental data with 13.0% absolute average relative error and R2 = 0.84. By comparison, the second best correlation reports absolute average relative errors of 120% and 37%, and R2 = 0.40 and 0.17, respectively. Furthermore, two key assumptions made in the CMFD simulations are justified with simulations and experiments: (i) the lubricating liquid film formed above the bubble as the pipe inclines with respect to the horizontal does not breakup, i.e., the gas phase never touches the pipe wall and triple line is not formed; and (ii) the Taylor bubble length does not affect its dynamics in inclined pipes. To verify the robustness of the first assumption, the gravity-induced film drainage is analytically modeled and experimentally validated. From this model, a criterion to avoid film breakup is obtained, which holds in the simulations performed. The second assumption is validated with both experiments and simulations. Finally, simulations of Taylor bubbles in upward and downward fluid flow in vertical and inclined pipes are performed, from where it is concluded that an improvement of the current velocity prediction models is needed. In particular, Taylor bubbles in vertical downward flow where the bubble becomes non-axisymmetric at high enough liquid flows are remarkably ill-predicted by current correlations.
Download or read book The Rise of Taylor Bubbles in Vertical and Inclined Pipes written by Enass Z. Massoud and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dimensionless analysis shows that different governing parameters appear according to the range of pipe inclination angle. The adopted CFD model shows good results for the dynamics of the Taylor bubble covering three main regions the bubble nose, the bubble body and the bubble wake regions.
Download or read book Direct Numerical Simulations of Gas Liquid Multiphase Flows written by Grétar Tryggvason and published by Cambridge University Press. This book was released on 2011-03-10 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurately predicting the behaviour of multiphase flows is a problem of immense industrial and scientific interest. Modern computers can now study the dynamics in great detail and these simulations yield unprecedented insight. This book provides a comprehensive introduction to direct numerical simulations of multiphase flows for researchers and graduate students. After a brief overview of the context and history the authors review the governing equations. A particular emphasis is placed on the 'one-fluid' formulation where a single set of equations is used to describe the entire flow field and interface terms are included as singularity distributions. Several applications are discussed, showing how direct numerical simulations have helped researchers advance both our understanding and our ability to make predictions. The final chapter gives an overview of recent studies of flows with relatively complex physics, such as mass transfer and chemical reactions, solidification and boiling, and includes extensive references to current work.
Download or read book Multiphase Flow Analysis Using Population Balance Modeling written by Guan Heng Yeoh and published by Butterworth-Heinemann. This book was released on 2013-08-19 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by leading multiphase flow and CFD experts, this book enables engineers and researchers to understand the use of PBM and CFD frameworks. Population balance approaches can now be used in conjunction with CFD, effectively driving more efficient and effective multiphase flow processes. Engineers familiar with standard CFD software, including ANSYS-CFX and ANSYS–Fluent, will be able to use the tools and approaches presented in this book in the effective research, modeling and control of multiphase flow problems. - Builds a complete understanding of the theory behind the application of population balance models and an appreciation of the scale-up of computational fluid dynamics (CFD) and population balance modeling (PBM) to a variety of engineering and industry applications in chemical, pharmaceutical, energy and petrochemical sectors - The tools in this book provide the opportunity to incorporate more accurate models in the design of chemical and particulate based multiphase processes - Enables readers to translate theory to practical use with CFD software
Download or read book Experimental Investigation of the Flow Field in the Wake of a Taylor Bubble and Its Effect on the Motion of a Consecutive Bubble in Vertical Slug Flow written by Anna Gulitski and published by . This book was released on 2005 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigation of Taylor Bubble Acceleration Mechanism in Slug Flow written by Eugenia-Teodora Tudose and published by . This book was released on 1997 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bubbly Flows written by Martin Sommerfeld and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book summarises the outcom of a priority research programme: 'Analysis, Modelling and Computation of Multiphase Flows'. The results of 24 individual research projects are presented. The main objective of the research programme was to provide a better understanding of the physical basis for multiphase gas-liquid flows as they are found in numerous chemical and biochemical reactors. The research comprises steady and unsteady multiphase flows in three frequently found reactor configurations, namely bubble columns without interiors, airlift loop reactors, and aerated stirred vessels. For this purpose new and improved measurement techniques were developed. From the resulting knowledge and data, new and refined models for describing the underlying physical processes were developed, which were used for the establishment and improvement of analytic as well as numerical methods for predicting multiphase reactors. Thereby, the development, lay-out and scale-up of such processes should be possible on a more reliable basis.
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 The Transition from Two Phase Bubble Flow to Slug Flow written by Nick Anthony Radovcich and published by . This book was released on 1962 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: The process of transition from bubble to slug flow in a vertical pipe has been studied analytically and experimentally. An equation is presented which gives the agglomeration time as a function of void fraction, channel diamet r, initial bubble diameter and liquid purity. A dependent function which also appears in the equation was evaluated using experimental data. A reasonably good correlation of data was achieved. (Author).
Download or read book Experimental Investigation of Taylor Bubble Acceleration Mechanism in Slug Flow written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bubbles Drops and Particles written by R. Clift and published by Courier Corporation. This book was released on 2013-04-22 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume offers a unified treatment and critical review of the literature related to the fluid dynamics, heat transfer, and mass transfer of single bubbles, drops, and particles. 1978 edition.
Download or read book Gas liquid Flows written by Barry J. Azzopardi and published by Begell House Publishers. This book was released on 2006-01-01 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiphase Science and Technology written by G.F. Hewitt and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the second volume of Multiphase Science and TechnoJogy, a new international series of books intended to provide authoritative overviews of im portant areas in multiphase systems. The alm is to have systematic and tutorial presentations of the state of knowledge in various areas. The objective of the chapters is to allow the nonspecialist reader to gain an up-to-date idea of the present state of development in a given subject. The response to Volume 1 of the se ries has been very positive, and we believe that the present volume will be equally weil received. Volume 1 was concerned entirely with gas-liquid systems, and the first four chapters of the present volume also relate to such systems. However, the inten tion of the se ries is to cover a wide range of multiphase systems, and we are, therefore, pleased to include in the present volume chapters that refer to liquid liquid and gas-solid multiphase flows, respectively. The first chapter in the present volume is by Professor A. E. Dukler of the University of Houston, Texas, and Professor Y. Taitel of Tel-Aviv University, Israel.
Download or read book Two Phase Flow written by Cl Kleinstreuer and published by CRC Press. This book was released on 2003-05-23 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This graduate text provides a unified treatment of the fundamental principles of two-phase flow and shows how to apply the principles to a variety of homogeneous mixture as well as separated liquid-liquid, gas-solid, liquid-solid, and gas-liquid flow problems, which may be steady or transient, laminar or turbulent. Each chapter contains several sample problems, which illustrate the outlined theory and provide approaches to find simplified analytic descriptions of complex two-phase flow phenomena. This well-balanced introductory text will be suitable for advanced seniors and graduate students in mechanical, chemical, biomedical, nuclear, environmental and aerospace engineering, as well as in applied mathematics and the physical sciences. It will be a valuable reference for practicing engineers and scientists. A solutions manual is available to qualified instructors.
Download or read book Numerical Methods for Fluid Dynamics written by Institute of Mathematics and Its Applications and published by . This book was released on 1982 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Studies of Millimeter sized Bubbles in an Electrolytic Solution written by Ying Hang Tsang and published by . This book was released on 2005 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Multiphase Flow Study of Bubbles Traveling Through Bifurcations for a Novel Gas Embolotherapy Application written by Andres Javier Calderon and published by . This book was released on 2006 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:
