Download or read book Modeling Gas liquid Bubble Flow and Computational Fluid Dynamics Simulation of Interfacial Area Concentration in Bubble Columns written by Asem M. Al Jarrah and published by . This book was released on 2006 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was found that, in a fully developed turbulent flow bubble column, the liquid and gas velocity profiles far from the wall are approximately flat. Close to the wall, the velocity profiles are very sharp. In general, the velocity profiles for the gas and the liquid are similar to the velocity profile of one fluid flow in a pipe.
Download or read book Computational Fluid Dynamics Simulation of Interfacial Area Concentration in a Bubble Column written by Mohammad A. Aliedeh and published by . This book was released on 2004 with total page 460 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 Computational Fluid Dynamics Simulations of Phase Distribution in Adiabatic Upward Bubbly Flows Using Interfacial Area Transport Equation written by Xia Wang and published by . This book was released on 2007 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In analyzing gas-liquid two-phase flows, it is imperative to take into account the bubble-bubble and bubble-eddy interactions, which may result in bubble coalescence and/or disintegration. The bubble coalescence and disintegration will further affect the interfacial structure, which could, to a first-order approximation, be characterized by the interfacial area concentration and void fraction. In this thesis, a one-group interfacial area transport equation (IATE) that was developed in the literature to describe the evolution of the interfacial area concentration in bubbly flows was implemented into a computational fluid dynamics (CFD) code, namely, FLUENT. Previous studies demonstrated that the following three bubble interaction mechanisms were essential in bubby flows of interest: coalescence of bubbles due to bubble random collisions driven by turbulence, coalescence of bubbles due to wake entrainment, and disintegration of bubbles caused by turbulent eddy impact. These three mechanisms have been taken into account in the one-group IATE. The current study focuses on examining the capability of FLUENT with the one-group IATE in predicting the phase distribution in adiabatic bubbly flows. Eulerian multiphase model in FLUENT 6.2.16 is applied, in which two sets of conservation equations are applied to each phase separately but coupled through interfacial transfer terms. The constitutive relations of the interfacial transfers are provided using the interfacial area concentration described through the IATE. CFD simulations of adiabatic upward bubbly flows in a circular pipe have been carried out in this study. In the simulation, the interfacial area concentration is first introduced into FLUENT as a user- defined scalar and then the corresponding IATE is solved for the interfacial area concentration. In addition, the associated modifications to the interfacial drag force model and turbulence model are made to reflect the evolution of the bubble size by replacing the constant bubble diameter in those models with the Sauter mean diameter, which is a function of the void fraction and interfacial area concentration. With comparisons between the simulation results and available experimental data, satisfactory agreement has been achieved, which demonstrates that FLUENT code with the one-group IATE provide valuable simulation tool for bubbly two-phase flows.
Download or read book Reactive Bubbly Flows written by Michael Schlüter and published by Springer Nature. This book was released on 2021-07-29 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents experimental and numerical methods that have been developed during six years of targeted research within the DFG priority program SPP 1740, elucidating the interaction between hydrodynamics, mass transfer and transport as well as chemical reactions in bubbly flows. A special feature of this book is its focus on an interdisciplinary research approach with contributions from chemistry, mathematics and engineering sciences, providing enhanced or novel experimental methods, models and numerical simulations. This book provides fundamental knowledge to students about the current state of knowledge regarding transport processes in reactive bubbly flows as well as to scientists, emphasizing pressing research questions and further current demands for fundamental research. Engineers from the chemical industries will get valuable insights into relevant gas-liquid processes and benefit from recommendations concerning the design of gas-liquid reactors and laboratory experiments for studying the performance of gas-liquid reactions in their own lab.
Download or read book Multiphase Flows for Process Industries written by Vivek V. Ranade and published by John Wiley & Sons. This book was released on 2022-03-30 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover the cutting-edge in multiphase flows used in the process industries In Multiphase Flows for Process Industries: Fundamentals and Applications, a team of accomplished chemical engineers delivers an insightful and complete treatment of the state-of-the-art in commonly encountered multiphase flows in the process industries. After discussing the theoretical background, experimental methods, and computational methods applicable to multiphase flows, the authors explore specific examples from the process industries. The book covers a wide range of multiphase flows, including gas-solid fluidized beds and flows with phase change. It also provides direction on how to use current advances in the field to realize efficient and optimized processes. Filling the gap between theory and practice, this unique reference also includes: A thorough introduction to multiphase flows and the process industry Practical discussions of flow regimes, lower order models and correlations, and the chronological development of mathematical models for multiphase flows Comprehensive explorations of experimental methods for characterizing multiphase flows, including flow imaging and visualization In-depth examinations of computational models for simulating multiphase flows Perfect for chemical and process engineers, Multiphase Flows for Process Industries: Fundamentals and Applications is required reading for graduate and doctoral students in the engineering sciences, as well as professionals in the chemical industry.
Download or read book Modelling of Hydrodynamics in Heterogeneous Bubble Column written by Mohd Shahimie Selamat and published by . This book was released on 2010 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The applications of bubble columns are very important as multiphase contactors and reactors in process industry. They are wide and extensively used in chemical, petrochemical and biochemical industries. The advantages of bubble column are low maintenance and operating cost due to the compactness and no moving part. They also have an excellent mass and heat transfer characteristic or high heat and mass transfer coefficients, and high durability of catalyst or packing material. It is important to understand the nature of hydrodynamics and operational parameters to characterize their operation including pressure drop, gas superficial velocity, bubble rise velocity, etc., to do the design and scale-up process. Although experimental methods are available to elucidate the multiphase flow in bubble column by the means of advanced experimental methods i.e. X-ray tomography and laser doppler anemometry, the experimental setup is often expensive to develop. Alternatively, the computational fluid dynamics can be used to evaluate the performance of bubble column at lower cost compared to experimental setup. In this work commercial CFD software, FLUENT 6.3 was employed for modeling of gasliquid flow in a bubble column. Multiphase simulations were performed using an Eulerian-Eulerian two-fluid model and the drag coefficient of spherical and distorted bubbles was modeled using the Tomiyama (1995) and Schiller-Naumann (1935) models. The effect of the void fractions on the drag coefficient was modeled using the correlation by Behzadi (2004). The CFD predictions were compared to the experimental measurement adopted from literature. The CFD predicts the turbulent kinetic energy, gas hold-up and the liquid axial velocity fairly well, although the results seem to suggest that further improvement on the interfacial exchange models and possibly further refinement on the two-fluid modeling approaches are necessary especially for the liquid axial velocity and turbulent kinetic energy. It is clear from the modeling exercise performed in this work that CFD is a great method for modeling the performance of bubble column. Furthermore, the CFD method is certainly less expensive than the experimental characterization studies.
Download or read book Development of a Computationally Efficient Bubble Column Simulation Approach by Way of Statistical Bubble Micro flow Modelling written by Waldo Coetzee and published by . This book was released on 2013 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermo fluid Dynamics of Two Phase Flow written by Mamoru Ishii and published by Springer Science & Business Media. This book was released on 2006-09-28 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book has been written for graduate students, scientists and engineers who need in-depth theoretical foundations to solve two-phase problems in various technological systems. Based on extensive research experiences focused on the fundamental physics of two-phase flow, the authors present the detailed theoretical foundation of multi-phase flow thermo-fluid dynamics as they apply to a variety of scenarios, including nuclear reactor transient and accident analysis, energy systems, power generation systems and even space propulsion.
Download or read book An Experimental and Computational Study of Hydrodynamics and Mass Transfer in Gas liquid Bubble Columns written by Houman Shirzadi and published by . This book was released on 2012 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Methods in Multiphase Flow VIII written by P. Vorobieff and published by WIT Press. This book was released on 2015-04-20 with total page 549 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest research in one of the most challenging, yet most universally applicable areas of technology. Multiphase flows are found in all areas of technology, at all length scales and flow regimes, involving compressible or incompressible linear or nonlinear fluids. The range of related problems of interest is vast, including astrophysics, biology, geophysics, atmospheric process, and many areas of engineering. The solution of the equations that describe such complex problems often requires a combination of advanced computational and experimental methods. For example, any models developed must be validated through the application of expensive and difficult experimental techniques. Numerous problems in the area thus remain as yet unsolved, including modelling nonlinear fluids, modelling and tracking interfaces, dealing with multiple length scales, characterising phase structures, and treating drop break-up and coalescence. The papers contained in the book were presented at the eighth in a well established series of biennial conferences that began in 2001. They represent close interaction between numerical modellers and other researchers working to gradually resolve the many outstanding issues in understanding of multiphase flow. The papers in the book cover such topics as: Multiphase Flow Simulation; Bubble and Drop Dynamics; Interface Behaviour; Experimental Measurements; Energy Applications; Compressible Flows; Flow in Porous Media; Turbulent Flow; Image Processing; Heat Transfer; Atomization; Hydromagnetics; Plasma; Fluidised Beds; Cavitation.
Download or read book Chemical Engineering in the Pharmaceutical Industry Active Pharmaceutical Ingredients written by David J. am Ende and published by John Wiley & Sons. This book was released on 2019-03-28 with total page 1168 pages. Available in PDF, EPUB and Kindle. Book excerpt: A guide to the development and manufacturing of pharmaceutical products written for professionals in the industry, revised second edition The revised and updated second edition of Chemical Engineering in the Pharmaceutical Industry is a practical book that highlights chemistry and chemical engineering. The book’s regulatory quality strategies target the development and manufacturing of pharmaceutically active ingredients of pharmaceutical products. The expanded second edition contains revised content with many new case studies and additional example calculations that are of interest to chemical engineers. The 2nd Edition is divided into two separate books: 1) Active Pharmaceutical Ingredients (API’s) and 2) Drug Product Design, Development and Modeling. The active pharmaceutical ingredients book puts the focus on the chemistry, chemical engineering, and unit operations specific to development and manufacturing of the active ingredients of the pharmaceutical product. The drug substance operations section includes information on chemical reactions, mixing, distillations, extractions, crystallizations, filtration, drying, and wet and dry milling. In addition, the book includes many applications of process modeling and modern software tools that are geared toward batch-scale and continuous drug substance pharmaceutical operations. This updated second edition: • Contains 30new chapters or revised chapters specific to API, covering topics including: manufacturing quality by design, computational approaches, continuous manufacturing, crystallization and final form, process safety • Expanded topics of scale-up, continuous processing, applications of thermodynamics and thermodynamic modeling, filtration and drying • Presents updated and expanded example calculations • Includes contributions from noted experts in the field Written for pharmaceutical engineers, chemical engineers, undergraduate and graduate students, and professionals in the field of pharmaceutical sciences and manufacturing, the second edition of Chemical Engineering in the Pharmaceutical Industry focuses on the development and chemical engineering as well as operations specific to the design, formulation, and manufacture of drug substance and products.
Download or read book Computational Techniques for Multiphase Flows written by Guan Heng Yeoh and published by Elsevier. This book was released on 2009-10-07 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixed or multiphase flows of solid/liquid or solid/gas are commonly found in many industrial fields, and their behavior is complex and difficult to predict in many cases. The use of computational fluid dynamics (CFD) has emerged as a powerful tool for the understanding of fluid mechanics in multiphase reactors, which are widely used in the chemical, petroleum, mining, food, beverage and pharmaceutical industries. Computational Techniques for Multiphase Flows enables scientists and engineers to the undertand the basis and application of CFD in muliphase flow, explains how to use the technique, when to use it and how to interpret the results and apply them to improving aplications in process enginering and other multiphase application areas including the pumping, automotive and energy sectors. Understandable guide to a complex subject Important in many industries Ideal for potential users of CFD
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 Direct and Large Eddy Simulation IV written by Bernard Geurts and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the 2001 DLES4 workshop. It describes and discusses state-of-the-art modeling and simulation approaches for complex flows. Fundamental turbulence and modeling issues but also elements from modern numerical analysis are at the heart of this field of interest.
Download or read book Hydrodynamics and Mass Transfer in Bubble Columns written by Onkar N. Manjrekar and published by . This book was released on 2016 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bubble columns and slurry bubble columns are multiphase reactors used for a wide range of applications in the biochemical, chemical, petrochemical, and metallurgical industries. In spite of their widespread usage, the scale-up of bubble columns remains an ongoing challenge. Various scale-up approaches, based on concepts ranging from ideal mixing to complex 3-D multiphase CFD models, have been used for assessing the effect of column size and gas and liquid flow rates on column hydrodynamics and reactor performance. Among these approaches, phenomenological models based on either single-class or multi-class bubbles that were validated on cold flow systems have been successful in predicting the residence time distributions of gas and liquid in pilot-scale bubble columns (Chen et al., 2004) (Gupta, 2002). However, such models are not entirely predictive, since they are validated using columns having the same size as hot operating units. To provide better predictive capability, we need prior knowledge of local hold-up, transport coefficients, and bubble dynamics. This dissertation provides an improved understanding of the key design parameters (gas hold-up, volumetric mass transfer coefficients, gas-liquid interfacial area, and their spatial distribution) for predictive scale-up of bubble columns. In this work, a 4-point optical probe is used to estimate local gas hold-up and bubble dynamics (specific interfacial area, frequency, bubble velocity, and bubble chord-lengths) and their radial profiles in a cold-flow slurry bubble column and a bubble column photo-bioreactor. Along with local bubble dynamics, the effect of superficial gas velocity on volumetric mass transport coefficients in several sizes of bubble columns, with and without internals, and in slurry bubble columns and photo-bioreactors are studied. Key findings: In the bubbly flow regime, bubble dynamics in photo-bioreactors with suspended algae were dominated by the physicochemical properties of the liquid, as distinguished from the churn-turbulent flow regime in the slurry bubble columns, where bubble dynamics were mainly affected by turbulent intensities. In the bubbly-flow regime, volumetric mass transfer coefficients increased with an increase in superficial gas velocity. However, in the churn-turbulent flow regime, they approached a constant value with an increase in the superficial gas velocity. A new methodology was proposed to identify the flow regime from optical probe signals based on the support vector machine algorithm, which can uniquely classify flow regimes for various systems on a single flow regime map. A new model for the liquid phase mixing, that with a proper choice of the mass transfer coefficients enables a good match of the predicted and measured tracer response is described. This model provides a better prediction of volumetric mass transfer coefficients than the currently used well mixed model for the liquid phase (CSTR). The dissertation improves the fundamental understanding of the connection between bubble dynamics and mass transfer. Using the 4-point optical probe as a tool, it demonstrates a connection between bubble dynamics and volumetric mass transfer coefficients. Present work addresses the need of industries to have a method that can be used as an online process control tool to identify flow regime, this method has been tested at cold flow conditions and needs to be implemented at hot flow conditions. The parameters (radial distributions of gas hold-up, bubble velocities, and volumetric mass transfer coefficient) that are evaluated in the present work can be used to validate phenomenological models and CFD results at cold flow conditions, which can later be combined with process chemistry to accomplish scale-up (Chen et al., 2004). The open literature on multiphase reactors is mainly limited to cold flow condition, and techniques such as the optical probe need to be extended to hot flow conditions. The optical probe described here can withstand high temperature and pressure, but for hot flow conditions it requires a better binding agent to hold the probe tips together, one that will not dissolve in industrial solvents.
Download or read book Population Balances written by Doraiswami Ramkrishna and published by Elsevier. This book was released on 2000-08-08 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineers encounter particles in a variety of systems. The particles are either naturally present or engineered into these systems. In either case these particles often significantly affect the behavior of such systems. This book provides a framework for analyzing these dispersed phase systems and describes how to synthesize the behavior of the population particles and their environment from the behavior of single particles in their local environments. Population balances are of key relevance to a very diverse group of scientists, including astrophysicists, high-energy physicists, geophysicists, colloid chemists, biophysicists, materials scientists, chemical engineers, and meteorologists. Chemical engineers have put population balances to most use, with applications in the areas of crystallization; gas-liquid, liquid-liquid, and solid-liquid dispersions; liquid membrane systems; fluidized bed reactors; aerosol reactors; and microbial cultures. Ramkrishna provides a clear and general treatment of population balances with emphasis on their wide range of applicability. New insight into population balance models incorporating random particle growth, dynamic morphological structure, and complex multivariate formulations with a clear exposition of their mathematical derivation is presented. Population Balances provides the only available treatment of the solution of inverse problems essential for identification of population balance models for breakage and aggregation processes, particle nucleation, growth processes, and more. This book is especially useful for process engineers interested in the simulation and control of particulate systems. Additionally, comprehensive treatment of the stochastic formulation of small systems provides for the modeling of stochastic systems with promising new areas of applications such as the design of sterilization systems and radiation treatment of cancerous tumors. A clear and general treatment of population balances with emphasis on their wide range of applicability. Thus all processes involving solid-fluid and liquid-liquid dispersions, biological populations, etc. are encompassed Provides new insight into population balance models incorporating random particle growth, dynamic morphological structure, and complex multivariate formulations with a clear exposition of their mathematical derivation Presents a wide range of solution techniques, Monte Carlo simulation methods with a lucid exposition of their origin and scope for enhancing computational efficiency An account of self-similar solutions of population balance equations and their significance to the treatment of data on particulate systems The only available treatment of the solution of inverse problems essential for identification of population balance models for breakage and aggregation processes, particle nucleation and growth processes and so on A comprehensive treatment of the stochastic formulation of small systems with several new applications
