Routes to Absolute Instability in Porous Media
Routes to Absolute Instability in Porous Media

Author: Antonio Barletta

Publisher:

Published: 2019

Total Pages:

ISBN-13: 9783030061951

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This book addresses the concepts of unstable flow solutions, convective instability and absolute instability, with reference to simple (or toy) mathematical models, which are mathematically simple despite their purely abstract character. Within this paradigm, the book introduces the basic mathematical tools, Fourier transform, normal modes, wavepackets and their dynamics, before reviewing the fundamental ideas behind the mathematical modelling of fluid flow and heat transfer in porous media. The author goes on to discuss the fundamentals of the Rayleigh-Bénard instability and other thermal instabilities of convective flows in porous media, and then analyses various examples of transition from convective to absolute instability in detail, with an emphasis on the formulation, deduction of the dispersion relation and study of the numerical data regarding the threshold of absolute instability. The clear descriptions of the analytical and numerical methods needed to obtain these parametric threshold data enable readers to apply them in different or more general cases. This book is of interest to postgraduates and researchers in mechanical and thermal engineering, civil engineering, geophysics, applied mathematics, fluid mechanics, and energy technology.

Routes to Absolute Instability in Porous Media
Routes to Absolute Instability in Porous Media

Author: Antonio Barletta

Publisher: Springer

Published: 2019-01-02

Total Pages: 283

ISBN-13: 3030061949

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This book addresses the concepts of unstable flow solutions, convective instability and absolute instability, with reference to simple (or toy) mathematical models, which are mathematically simple despite their purely abstract character. Within this paradigm, the book introduces the basic mathematical tools, Fourier transform, normal modes, wavepackets and their dynamics, before reviewing the fundamental ideas behind the mathematical modelling of fluid flow and heat transfer in porous media. The author goes on to discuss the fundamentals of the Rayleigh-Bénard instability and other thermal instabilities of convective flows in porous media, and then analyses various examples of transition from convective to absolute instability in detail, with an emphasis on the formulation, deduction of the dispersion relation and study of the numerical data regarding the threshold of absolute instability. The clear descriptions of the analytical and numerical methods needed to obtain these parametric threshold data enable readers to apply them in different or more general cases. This book is of interest to postgraduates and researchers in mechanical and thermal engineering, civil engineering, geophysics, applied mathematics, fluid mechanics, and energy technology.

Physical and Chemical Dissolution Front Instability in Porous Media
Physical and Chemical Dissolution Front Instability in Porous Media

Author: Chongbin Zhao

Publisher: Springer

Published: 2014-07-18

Total Pages: 363

ISBN-13: 3319084615

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This monograph provides state-of-the-art theoretical and computational findings from investigations on physical and chemical dissolution front instability problems in porous media, based on the author’s own work. Although numerical results are provided to complement theoretical ones, the focus of this monograph is on the theoretical aspects of the topic and those presented in this book are applicable to a wide range of scientific and engineering problems involving the instability of nonlinear dynamic systems. To appeal to a wider readership, common mathematical notations are used to derive the theoretical solutions. The book can be used either as a useful textbook for postgraduate students or as a valuable reference book for computational scientists, mathematicians, engineers and geoscientists.

Gas Transport in Porous Media
Gas Transport in Porous Media

Author: Clifford K. Ho

Publisher: Springer Science & Business Media

Published: 2006-10-07

Total Pages: 442

ISBN-13: 140203962X

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CLIFFORD K. HOAND STEPHEN W. WEBB Sandia National Laboratories, P. O. Box 5800, Albuquerque, NM 87185, USA Gas and vapor transport in porous media occur in a number of important applications includingdryingofindustrialandfoodproducts,oilandgasexploration,environm- tal remediation of contaminated sites, and carbon sequestration. Understanding the fundamental mechanisms and processes of gas and vapor transport in porous media allows models to be used to evaluate and optimize the performance and design of these systems. In this book, gas and vapor are distinguished by their available states at stan- ? dard temperature and pressure (20 C, 101 kPa). If the gas-phase constituent can also exist as a liquid phase at standard temperature and pressure (e. g. , water, ethanol, toluene, trichlorothylene), it is considered a vapor. If the gas-phase constituent is non-condensable at standard temperature and pressure (e. g. , oxygen, carbon di- ide, helium, hydrogen, propane), it is considered a gas. The distinction is important because different processes affect the transport and behavior of gases and vapors in porous media. For example, mechanisms specific to vapors include vapor-pressure lowering and enhanced vapor diffusion, which are caused by the presence of a g- phase constituent interacting with its liquid phase in an unsaturated porous media. In addition, the “heat-pipe” exploits isothermal latent heat exchange during evaporation and condensation to effectively transfer heat in designed and natural systems.

Analysis and Simulation of Contact Problems
Analysis and Simulation of Contact Problems

Author: Peter Wriggers

Publisher: Springer Science & Business Media

Published: 2006-08-15

Total Pages: 393

ISBN-13: 3540317619

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This carefully edited book offers a state-of-the-art overview on formulation, mathematical analysis and numerical solution procedures of contact problems. The contributions collected in this volume summarize the lectures presented by leading scientists in the area of contact mechanics, during the 4th Contact Mechanics International Symposium (CMIS) held in Hannover, Germany, 2005.

Solid-fluid Interactions in Porous Media
Solid-fluid Interactions in Porous Media

Author: Einat Aharonov

Publisher:

Published: 1996

Total Pages: 154

ISBN-13:

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This thesis studies how rocks evolve due to the coupled effects of flow and chemical reaction. The study was motivated by various experimental observations, both in igneous and sedimentary rocks. In the first part of this thesis, growth of microscopic, pore-scale, features in sedimentary rocks is theoretically investigated. It is found, in agreement with experiments, that statistical properties of pore-grain interfaces mirror growth conditions. The shapes of pore-grain intrefaces both influence and are influenced by large-scale transport properties of the rock. The second part of this thesis employs analytical methods to study flow patterns in melt upwelling beneath mid-ocean ridges. It is shown that high permeability channels spontaneously form, allowing for efficient extraction of melt from the system. This result may aid in understanding existing geochemical and geological observations. In the third part of this thesis, I present a new 3D computer model that simulates flow and reaction through a porous matrix. The model is used to study and compare the different characteristics of dissolution and deposition, and to simulate different settings for melt upwelling in the mantle.

Unsteady Combustor Physics
Unsteady Combustor Physics

Author: Tim C. Lieuwen

Publisher: Cambridge University Press

Published: 2012-08-27

Total Pages: 427

ISBN-13: 1139576836

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Developing clean, sustainable energy systems is a pre-eminent issue of our time. Most projections indicate that combustion-based energy conversion systems will continue to be the predominant approach for the majority of our energy usage. Unsteady combustor issues present the key challenge associated with the development of clean, high-efficiency combustion systems such as those used for power generation, heating or propulsion applications. This comprehensive study is unique, treating the subject in a systematic manner. Although this book focuses on unsteady combusting flows, it places particular emphasis on the system dynamics that occur at the intersection of the combustion, fluid mechanics and acoustic disciplines. Individuals with a background in fluid mechanics and combustion will find this book to be an incomparable study that synthesises these fields into a coherent understanding of the intrinsically unsteady processes in combustors.