Download or read book Numerical Modeling of Compressible Two Phase Flows with a Pressure Based Method written by Markus Boger and published by . This book was released on 2014 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics Of Multiphase Media written by Robert Iskanderovich Nigmatulin and published by CRC Press. This book was released on 1990-09-01 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 2 of a monograph on current knowledge of phenomena and the theory and analysis of multiphase systems, offering a systematic treatment of energy, mass and momentum exchange in multiphase systems along with other applications which include shock hardening of metals and boiling heat transfer.
Download or read book Multiphase Microfluidics The Diffuse Interface Model written by Roberto Mauri and published by Springer Science & Business Media. This book was released on 2012-05-31 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffuse interface (D.I.) model for muliphase flows.- Phase separation of viscous ternary liquid mixtures.- Dewetting and decomposing films of simple and complex liquids.- Phase-field models. Multiphase flows are typically described assuming that the different phases are separated by a sharp interface, with appropriate boundary conditions. This approach breaks down whenever the lengthscale of the phenomenon that is being studied is comparable with the real interface thickness, as it happens, for example, in the coalescence and breakup of bubbles and drops, the wetting and dewetting of solid surfaces and, in general, im micro-devices. The diffuse interface model resolves these problems by assuming that all quantities can vary continuously, so that interfaces have a non-zero thickness, i.e. they are "diffuse". The contributions in this book review the theory and describe some relevant applications of the diffuse interface model for one-component, two-phase fluids and for liquid binary mixtures, to model multiphase flows in confined geometries.
Download or read book A Novel Diffuse interface Model and Numerical Methods for Compressible Turbulent Two phase Flows and Scalar Transport written by Suhas Jain Suresh and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Compressible two-phase flows and the transport of scalars in two-phase flows have a wide range of applications in natural and engineering processes. In this thesis we first present a novel diffuse-interface model for the simulation of compressible two-phase flows. We start with the baseline five-equation model that consists of equations for the transport of volume fraction, mass of each phase, momentum, and total energy. It is known that this model cannot be used with a non-dissipative scheme as is, and the direct solution of these equations with a dissipative scheme results in artificial diffusion of the interface which results in poor accuracy. We, therefore, propose interface-regularization (diffusion--sharpening) terms to this five-equation model in such a way that the resulting model can now be used with a non-dissipative central scheme, and the model also maintains the discrete conservation of mass of each phase, momentum, and total energy of the system. For stable numerical simulations of compressible flows, it is known that a discrete entropy condition needs to be satisfied, and the discrete conservation of kinetic energy alone is not a sufficient condition, unlike in incompressible flows. To achieve this, we first propose discrete consistency conditions between the numerical fluxes, and then present a set of numerical fluxes--which satisfies these consistency conditions--that results in an exact discrete conservation of kinetic energy and approximate conservation of entropy (a KEEP scheme) in the absence of pressure work, viscosity, and thermal diffusion effects. Next, we also propose a novel scalar-transport model for the simulation of scalar quantities in two-phase flows. In a two-phase flow, the scalar quantities typically have very different diffusivities in the two phases, which results in effective confinement of the scalar quantities in one of the phases, in the time scales of interest. This confinement of the scalars leads to the formation of sharp gradients of the scalar concentration values at the interface and could result in artificial numerical leakage of the scalar and negative values for the scalar concentration values, presenting a serious challenge for its numerical simulations. To overcome this challenge, we propose a new consistent scalar-transport model that prevents artificial numerical leakage of the scalar at the interface. The proposed model also maintains the positivity property of the scalar concentration field, a physical realizability requirement for the simulation of scalars. Finally, we present numerical simulations to verify and validate the models presented in this work in a wide range of settings and regimes, spanning laminar to turbulent flows; and assess the accuracy, robustness, and scalability of the models.
Download or read book Small Scale Modeling and Simulation of Incompressible Turbulent Multi Phase Flow written by Stéphane Vincent and published by Springer Nature. This book was released on 2022-10-06 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides basic and recent research insights concerning the small scale modeling and simulation of turbulent multi-phase flows. By small scale, it has to be understood that the grid size for the simulation is smaller than most of the physical time and space scales of the problem. Small scale modeling of multi-phase flows is a very popular topic since the capabilities of massively parallel computers allows to go deeper into the comprehension and characterization of realistic flow configurations and at the same time, many environmental and industrial applications are concerned such as nuclear industry, material processing, chemical reactors, engine design, ocean dynamics, pollution and erosion in rivers or on beaches. The work proposes a complete and exhaustive presentation of models and numerical methods devoted to small scale simulation of incompressible turbulent multi-phase flows from specialists of the research community. Attention has also been paid to promote illustrations and applications, multi-phase flows and collaborations with industry. The idea is also to bring together developers and users of different numerical approaches and codes to share their experience in the development and validation of the algorithms and discuss the difficulties and limitations of the different methods and their pros and cons. The focus will be mainly on fixed-grid methods, however adaptive grids will be also partly broached, with the aim to compare and validate the different approaches and models.
Download or read book Numerical Simulations Of Incompressible Flows written by Mohamed M Hafez and published by World Scientific. This book was released on 2003-01-23 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of 37 articles dealing with simulation of incompressible flows and applications in many areas. It covers numerical methods and algorithm developments as well as applications in aeronautics and other areas. It represents the state of the art in the field.
Download or read book On the Formulation and Numerical Evaluation of a Set of Two phase Flow Equations Modelling the Cooldown Process written by Stephen Jarvis and published by . This book was released on 1965 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model of transient two-phase flow in a pipe is constructed in Eulerian coordinates assuming a single velocity but independent temperatures in the two phases.Experiments on the numerical integration of the system for Cooldown problem by both Lax and Courant-Isaacson-Rees methods indicate that a very fine spatial difference * net must be used to compensate for the numerical diffusion essential to computational stability if a second surge is to be realized. (Author).
Download or read book A Simple and Efficient Diffuse Interface Method for Compressible Two Phase Flows written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In nuclear reactor safety and optimization there are key issues that rely on in-depth understanding of basic two-phase flow phenomena with heat and mass transfer. For many reasons, to be discussed, there is growing interest in the application of two-phase flow models to provide diffuse, but nevertheless resolved, simulation of interfaces between two immiscible compressible fluids - diffuse interface method (DIM). Because of its ability to dynamically create interfaces and to solve interfaces separating pure media and mixtures for DNS-like (Direct Numerical Simulation) simulations of interfacial flows, we examine the construction of a simple, robust, fast, and accurate numerical formulation for the 5-equation Kapila et al. [1] reduced two-phase model. Though apparently simple, the Kapila et al. model contains a volume fraction differential transport equation containing a nonlinear, non-conservative term which poses serious computational challenges. To circumvent the difficulties encountered with the single velocity and single pressure Kapila et al. [1] multiphase flow model, a 6-equation relaxation hyperbolic model is built to solve interface problems with compressible fluids. In this approach, pressure non-equilibrium is first restored, followed by a relaxation to an asymptotic solution which is convergent to the solutions of the Kapila et al. reduced model. The apparent complexity introduced with this extended hyperbolic model actually leads to considerable simplifications regarding numerical resolution, and the various ingredients used by this method are general enough to consider future extensions to problems involving complex physics.
Download or read book Gasdynamic Aspects of Two Phase Flow written by Herbert Staedtke and published by John Wiley & Sons. This book was released on 2006-12-13 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, the author, a researcher of outstanding experience in this field, summarizes and combines the recent results and findings on advanced two-phase flow modeling and numerical methods otherwise dispersed in various journals, while also providing explanations for numerical and modeling techniques previously not covered by other books. The resulting systematic and comprehensive monograph is unrivalled in its kind, serving as a reference for both researchers and engineers working in engineering as well as in environmental science.
Download or read book Computational Methods in Multiphase Flow VII written by C. A. Brebbia and published by WIT Press. This book was released on 2013-07-03 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiphase flows are found in all areas of technology, at all length scales and flow regimes and can involve compressible or incompressible linear or nonlinear, fluids. However, although they are ubiquitous, multiphase flows continue to be one of the most challenging areas of computational mechanics, with numerous problems as yet unsolved. Advanced computational and experimental methods are often required to solve the equations that describe such complex problems. The many challenges that must be faced in solving them include modelling nonlinear fluids, modelling and tracking interfaces, dealing with multiple length scales, characterising phase structures, and treating drop break-up and coalescence. It is important to validate models, which calls for the use of expensive and difficult experimental techniques.This book presents contributions on the latest research in the techniques for solving multiphase flow problems, presented at the seventh in a biennial series of conferences on the subject that began in 2001. Featured topics include: Flow in porous media; Turbulent flow; Multiphase flow simulation; Image processing; Heat transfer; Atomization; Interface behaviour; Oil and gas applications; Experimental measurements; Energy applications; Biological flows; Micro and macro fluids; Compressible flows.
Download or read book Computational Methods for Multiphase Flow written by Andrea Prosperetti and published by Cambridge University Press. This book was released on 2009-06-25 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thanks to high-speed computers and advanced algorithms, the important field of modelling multiphase flows is an area of rapid growth. This one-stop account – now in paperback, with corrections from the first printing – is the ideal way to get to grips with this topic, which has significant applications in industry and nature. Each chapter is written by an acknowledged expert and includes extensive references to current research. All of the chapters are essentially independent and so the book can be used for a range of advanced courses and the self-study of specific topics. No other book covers so many topics related to multiphase flow, and it will therefore be warmly welcomed by researchers and graduate students of the subject across engineering, physics, and applied mathematics.
Download or read book Level Set Methods and Dynamic Implicit Surfaces written by Stanley Osher and published by Springer Science & Business Media. This book was released on 2006-04-06 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Very hot area with a wide range of applications; Gives complete numerical analysis and recipes, which will enable readers to quickly apply the techniques to real problems; Includes two new techniques pioneered by Osher and Fedkiw; Osher and Fedkiw are internationally well-known researchers in this area
Download or read book Computational Methods in Multiphase Flow VI written by Andrea Alberto Mammoli and published by WIT Press. This book was released on 2011 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiphase flows, which can involve compressible or incompressible linear or nonlinear, fluids, Are found in all areas of technology, at all length scales and flow regimes. In spite of their ubiquitousness, however multiphase flow continues to be one of the most challenging areas of computational mechanics and experimental methods, with numerous problems remaining unsolved to date. Because the multiphase flow problems are so complex, advanced computational and experimental methods are often required to solve the equations that describe them. The many hhallenges include modelling nonlinear fluids, modelling and tracking interfaces, dealing with multiple length scales, characterizing phase structures, and treating drop breakup and coalescence. Models must be validated, which requires the use of expensive and difficult experimental techniquess. This book presents contributions on the latest research in these techniques, presented at the sixth in a biennial series of conferences on the subject that begain in 2001. Featured topics include: Bubble and drop dynamics, Flow in porous media, Turbulent flow, Multiphase flow simulation, Image processing, Heat transfer, Interaction of gases, liquids and solids, Interface behaviour, Small scale phenomena, Atomization processes, and Liquid film behaviour.
Download or read book The Discrete Equation Method DEM for Fully Compressible Two Phase Flows in Ducts of Spatially Varying Cross Section written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Typically, multiphase modeling begins with an averaged (or homogenized) system of partial differential equations (traditionally ill-posed) then discretizes this system to form a numerical scheme. Assuming that the ill-posedness problem is avoided by using a well-posed formulation such as the seven-equation model, this presents problems for the numerical approximation of non-conservative terms at discontinuities (interfaces, shocks) as well as unwieldy treatment of fluxes with seven waves. To solve interface problems without conservation errors and to avoid this questionable determination of average variables and the numerical approximation of the non-conservative terms associated with 2 velocity mixture flows we employ a new homogenization method known as the Discrete Equations Method (DEM). Contrary to conventional methods, the averaged equations for the mixture are not used, and this method directly obtains a (well-posed) discrete equation system from the single-phase system to produce a numerical scheme which accurately computes fluxes for arbitrary numbers of phases and solves non-conservative products. The method effectively uses a sequence of single phase Riemann equation solves. Phase interactions are accounted for by Riemann solvers at each interface. Flow topology can change with changing expressions for the fluxes. Non-conservative terms are correctly approximated. Some of the closure relations missing from the traditional approach are automatically obtained. Lastly, we can often times identify the continuous equation system, resulting from taking the continuous limit with weak wave assumptions, of the discrete equations. This can be very useful from a theoretical standpoint. As a first step toward implict integration of the DEM method in multidimensions, in this paper we construct a DEM model for the flow of two compressible phases in 1-D ducts of spatially varying cross-section to test this approach. To relieve time step size restrictions due to stiffness and to achieve tighter coupling of equations, a fully implicit time integration method is employed. For the first time, we demonstrate on a converging-diverging two-phase nozzle that this well-posed, 2 pressure, 2 velocity DEM model can be integrated to a meaningful steady-state with both phases treated as compressible.
Download or read book Computational Methods for Two Phase Flows written by Peter D. M. Spelt and published by World Scientific Publishing Company Incorporated. This book was released on 2010 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book uniquely presents an overview of methods for the numerical simulation of a wide range of two-phase flows, aimed at a broad readership of engineers and scientists at graduate level. Given that numerous methods have been proposed recently in this field, the new book series could not have been more timely and much needed for an up-to-date overview of the advances, whilst not restricting the focus on two-phase flows or any particular method. The book is written by a team of leading experts who have contributed substantially to the development of the methods and who have also applied the concepts and theories to a diverse range of applications. Computational Methods for Two-Phase Flows is self-contained, and aims to elucidate and analyze the strong relations between the various numerical methods, beyond merely giving detailed summary of the various methods. A unique enhanced feature of the book is that the sample codes that come with the book provide further benefits and ease of use to readers to implement the various numerical methods. The book is the first volume of a new book series entitled Advances in Computational Fluid Dynamics, published by World Scientific.
Download or read book Turbulence and Interactions written by Michel O. Deville and published by Springer. This book was released on 2014-06-13 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents a snapshot of the state-of-art in the field of turbulence modeling and covers the latest developments concerning direct numerical simulations, large eddy simulations, compressible turbulence, coherent structures, two-phase flow simulation and other related topics. It provides readers with a comprehensive review of both theory and applications, describing in detail the authors’ own experimental results. The book is based on the proceedings of the third Turbulence and Interactions Conference (TI 2012), which was held on June 11-14 in La Saline-les-Bains, La Réunion, France and includes both keynote lectures and outstanding contributed papers presented at the conference. This multifaceted collection, which reflects the conference ́s emphasis on the interplay of theory, experiments and computing in the process of understanding and predicting the physics of complex flows and solving related engineering problems, offers a practice-oriented guide for students, researchers and professionals in the field of computational fluid dynamics, turbulence modeling and related areas.
Download or read book Two Phase Flows written by Shih-i Pai and published by Springer-Verlag. This book was released on 2013-07-02 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt:
