Modeling Gas-liquid Bubble Flow and Computational Fluid Dynamics Simulation of Interfacial Area Concentration in Bubble Columns

Modeling Gas-liquid Bubble Flow and Computational Fluid Dynamics Simulation of Interfacial Area Concentration in Bubble Columns PDF Author: Asem M. Al Jarrah
Publisher:
ISBN: 9781109872705
Category : Bubbles
Languages : en
Pages : 158

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Book Description
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.

Modeling Gas-liquid Bubble Flow and Computational Fluid Dynamics Simulation of Interfacial Area Concentration in Bubble Columns

Modeling Gas-liquid Bubble Flow and Computational Fluid Dynamics Simulation of Interfacial Area Concentration in Bubble Columns PDF Author: Asem M. Al Jarrah
Publisher:
ISBN: 9781109872705
Category : Bubbles
Languages : en
Pages : 158

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Book Description
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.

Bubbly Flows

Bubbly Flows PDF Author: Martin Sommerfeld
Publisher: Springer Science & Business Media
ISBN: 3642185401
Category : Science
Languages : en
Pages : 354

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Book Description
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.

Computational Fluid Dynamics Simulation of Interfacial Area Concentration in a Bubble Column

Computational Fluid Dynamics Simulation of Interfacial Area Concentration in a Bubble Column PDF Author: Mohammad A. Aliedeh
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 460

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Book Description


Computational Fluid Dynamics Simulations of Phase Distribution in Adiabatic Upward Bubbly Flows Using Interfacial Area Transport Equation

Computational Fluid Dynamics Simulations of Phase Distribution in Adiabatic Upward Bubbly Flows Using Interfacial Area Transport Equation PDF Author: Xia Wang
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 176

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Book Description
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.

Reactive Bubbly Flows

Reactive Bubbly Flows PDF Author: Michael Schlüter
Publisher: Springer Nature
ISBN: 3030723615
Category : Technology & Engineering
Languages : en
Pages : 642

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Book Description
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.

Thermo-fluid Dynamics of Two-Phase Flow

Thermo-fluid Dynamics of Two-Phase Flow PDF Author: Mamoru Ishii
Publisher: Springer Science & Business Media
ISBN: 0387291873
Category : Technology & Engineering
Languages : en
Pages : 462

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Book Description
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.

Multiphase Flows for Process Industries

Multiphase Flows for Process Industries PDF Author: Vivek V. Ranade
Publisher: John Wiley & Sons
ISBN: 3527812040
Category : Technology & Engineering
Languages : en
Pages : 838

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Book Description
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.

Modelling of Hydrodynamics in Heterogeneous Bubble Column

Modelling of Hydrodynamics in Heterogeneous Bubble Column PDF Author: Mohd Shahimie Selamat
Publisher:
ISBN:
Category : Bubbles
Languages : en
Pages : 42

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Book Description
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.

Development of a Computationally Efficient Bubble Column Simulation Approach by Way of Statistical Bubble Micro-flow Modelling

Development of a Computationally Efficient Bubble Column Simulation Approach by Way of Statistical Bubble Micro-flow Modelling PDF Author: Waldo Coetzee
Publisher:
ISBN:
Category :
Languages : en
Pages : 220

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Book Description


Bubbles, Drops, and Particles

Bubbles, Drops, and Particles PDF Author: R. Clift
Publisher: Courier Corporation
ISBN: 0486317749
Category : Science
Languages : en
Pages : 402

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Book Description
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.