Mathematical Modeling of Disperse Two-Phase Flows
Mathematical Modeling of Disperse Two-Phase Flows

Author: Christophe Morel

Publisher: Springer

Published: 2015-07-17

Total Pages: 365

ISBN-13: 3319201042

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This book develops the theoretical foundations of disperse two-phase flows, which are characterized by the existence of bubbles, droplets or solid particles finely dispersed in a carrier fluid, which can be a liquid or a gas. Chapters clarify many difficult subjects, including modeling of the interfacial area concentration. Basic knowledge of the subjects treated in this book is essential to practitioners of Computational Fluid Dynamics for two-phase flows in a variety of industrial and environmental settings. The author provides a complete derivation of the basic equations, followed by more advanced subjects like turbulence equations for the two phases (continuous and disperse) and multi-size particulate flow modeling. As well as theoretical material, readers will discover chapters concerned with closure relations and numerical issues. Many physical models are presented, covering key subjects including heat and mass transfers between phases, interfacial forces and fluid particles coalescence and breakup, amongst others. This book is highly suitable for students in the subject area, but may also be a useful reference text for more advanced scientists and engineers.

Two-Phase Flow
Two-Phase Flow

Author: Cl Kleinstreuer

Publisher: Routledge

Published: 2017-11-01

Total Pages: 472

ISBN-13: 1351406485

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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.

Modelling and Experimentation in Two-Phase Flow
Modelling and Experimentation in Two-Phase Flow

Author: Volfango Bertola

Publisher: Springer

Published: 2014-05-04

Total Pages: 433

ISBN-13: 3709125383

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This is an up-to-date review of recent advances in the study of two-phase flows, with focus on gas-liquid flows, liquid-liquid flows, and particle transport in turbulent flows. The book is divided into several chapters, which after introducing basic concepts lead the reader through a more complex treatment of the subjects. The reader will find an extensive review of both the older and the more recent literature, with abundance of formulas, correlations, graphs and tables. A comprehensive (though non exhaustive) list of bibliographic references is provided at the end of each chapter. The volume is especially indicated for researchers who would like to carry out experimental, theoretical or computational work on two-phase flows, as well as for professionals who wish to learn more about this topic.

Stability Improvement of the One-dimensional Two-fluid Model for Horizontal Two-phase Flow with Model Unification
Stability Improvement of the One-dimensional Two-fluid Model for Horizontal Two-phase Flow with Model Unification

Author: Kent C. Abel

Publisher:

Published: 2005

Total Pages: 302

ISBN-13:

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The next generation of nuclear safety analysis computer codes will require detailed modeling of two-phase fluid flow. The most complete and fundamental model used for these calculations is known as the two-fluid model. It is the most accurate of the two-phase models since it considers each phase independently and links the two phases together with six conservation equations. A major drawback is that the current two-fluid model, when area-averaged to create a one-dimensional model, becomes ill-posed as an initial value problem when the gas and liquid velocities are not equal. The importance of this research lies in obtaining a model that overcomes this difficulty. It is desired to develop a modified one-dimensional two-fluid model for horizontal flow that accounts for the pressure difference between the two phases, due to hydrostatic head, with the implementation of a void fraction distribution parameter. With proper improvement of the one-dimensional two-fluid model, the next generation of nuclear safety analysis computer codes will be able to predict, with greater precision, the key safety parameters of an accident scenario. As part of this research, an improved version of the one-dimensional two-fluid model for horizontal flows was developed. The model was developed from a theoretical point of view with the three original distribution parameters simplified down to a single parameter. The model was found to greatly enhance the numerical stability (hyperbolicity) of the solution method. With proper modeling of the phase distribution parameter, a wide range of flow regimes can be modeled. This parameter could also be used in the future to eliminate the more subjective flow regime maps that are currently implemented in today's multiphase computer codes. By incorporating the distribution parameter and eliminating the flow regime maps, a hyperbolic model is formed with smooth transitions between various flow regimes, eliminating the unphysical oscillations that may occur near transition boundaries in today's multiphase computer codes.

A Two-Equation Turbulence Model for a Dispersed Two-Phased Flow with Variable Density Fluid and Constant Density Particles
A Two-Equation Turbulence Model for a Dispersed Two-Phased Flow with Variable Density Fluid and Constant Density Particles

Author: Gordon C. K. Yeh

Publisher:

Published: 1985

Total Pages: 44

ISBN-13:

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A two equation turbulence model has been developed for predicting a dispersed two phase flow with variable density fluid and constant density particles. The two equations describe the conservation of turbulence kinetic energy and its dissipation rate for the fluid. They have been derived rigorously from the momentum equations of the carrier fluid in the two phase flow. Closure of the time mean equations is achieved by modeling the turbulent correlations up to third order. The new model eliminates the need to simulate in an ad hoc manner the effects of the dispersed phase on turbulent structure in situations where the compressibility of the fluid must be taken into account.