Buoyancy-Thermocapillary Convection of Volatile Fluids in Confined and Sealed Geometries

Buoyancy-Thermocapillary Convection of Volatile Fluids in Confined and Sealed Geometries PDF Author: Tongran Qin
Publisher: Springer
ISBN: 3319613316
Category : Science
Languages : en
Pages : 217

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Book Description
This thesis represents the first systematic description of the two-phase flow problem. Two-phase flows of volatile fluids in confined geometries driven by an applied temperature gradient play an important role in a range of applications, including thermal management, such as heat pipes, thermosyphons, capillary pumped loops and other evaporative cooling devices. Previously, this problem has been addressed using a piecemeal approach that relied heavily on correlations and unproven assumptions, and the science and technology behind heat pipes have barely evolved in recent decades. The model introduced in this thesis, however, presents a comprehensive physically based description of both the liquid and the gas phase. The model has been implemented numerically and successfully validated against the available experimental data, and the numerical results are used to determine the key physical processes that control the heat and mass flow and describe the flow stability. One of the key contributions of this thesis work is the description of the role of noncondensables, such as air, on transport. In particular, it is shown that many of the assumptions used by current engineering models of evaporative cooling devices are based on experiments conducted at atmospheric pressures, and these assumptions break down partially or completely when most of the noncondensables are removed, requiring a new modeling approach presented in the thesis. Moreover, Numerical solutions are used to motivate and justify a simplified analytical description of transport in both the liquid and the gas layer, which can be used to describe flow stability and determine the critical Marangoni number and wavelength describing the onset of the convective pattern. As a result, the results presented in the thesis should be of interest both to engineers working in heat transfer and researchers interested in fluid dynamics and pattern formation.

Buoyancy-Thermocapillary Convection of Volatile Fluids in Confined and Sealed Geometries

Buoyancy-Thermocapillary Convection of Volatile Fluids in Confined and Sealed Geometries PDF Author: Tongran Qin
Publisher: Springer
ISBN: 3319613316
Category : Science
Languages : en
Pages : 217

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Book Description
This thesis represents the first systematic description of the two-phase flow problem. Two-phase flows of volatile fluids in confined geometries driven by an applied temperature gradient play an important role in a range of applications, including thermal management, such as heat pipes, thermosyphons, capillary pumped loops and other evaporative cooling devices. Previously, this problem has been addressed using a piecemeal approach that relied heavily on correlations and unproven assumptions, and the science and technology behind heat pipes have barely evolved in recent decades. The model introduced in this thesis, however, presents a comprehensive physically based description of both the liquid and the gas phase. The model has been implemented numerically and successfully validated against the available experimental data, and the numerical results are used to determine the key physical processes that control the heat and mass flow and describe the flow stability. One of the key contributions of this thesis work is the description of the role of noncondensables, such as air, on transport. In particular, it is shown that many of the assumptions used by current engineering models of evaporative cooling devices are based on experiments conducted at atmospheric pressures, and these assumptions break down partially or completely when most of the noncondensables are removed, requiring a new modeling approach presented in the thesis. Moreover, Numerical solutions are used to motivate and justify a simplified analytical description of transport in both the liquid and the gas layer, which can be used to describe flow stability and determine the critical Marangoni number and wavelength describing the onset of the convective pattern. As a result, the results presented in the thesis should be of interest both to engineers working in heat transfer and researchers interested in fluid dynamics and pattern formation.

Applied Mechanics Reviews

Applied Mechanics Reviews PDF Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 1208

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Book Description


Geometries

Geometries PDF Author: Alekseĭ Bronislavovich Sosinskiĭ
Publisher: American Mathematical Soc.
ISBN: 082187571X
Category : Mathematics
Languages : en
Pages : 322

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Book Description
The book is an innovative modern exposition of geometry, or rather, of geometries; it is the first textbook in which Felix Klein's Erlangen Program (the action of transformation groups) is systematically used as the basis for defining various geometries. The course of study presented is dedicated to the proposition that all geometries are created equal--although some, of course, remain more equal than others. The author concentrates on several of the more distinguished and beautiful ones, which include what he terms ``toy geometries'', the geometries of Platonic bodies, discrete geometries, and classical continuous geometries. The text is based on first-year semester course lectures delivered at the Independent University of Moscow in 2003 and 2006. It is by no means a formal algebraic or analytic treatment of geometric topics, but rather, a highly visual exposition containing upwards of 200 illustrations. The reader is expected to possess a familiarity with elementary Euclidean geometry, albeit those lacking this knowledge may refer to a compendium in Chapter 0. Per the author's predilection, the book contains very little regarding the axiomatic approach to geometry (save for a single chapter on the history of non-Euclidean geometry), but two Appendices provide a detailed treatment of Euclid's and Hilbert's axiomatics. Perhaps the most important aspect of this course is the problems, which appear at the end of each chapter and are supplemented with answers at the conclusion of the text. By analyzing and solving these problems, the reader will become capable of thinking and working geometrically, much more so than by simply learning the theory. Ultimately, the author makes the distinction between concrete mathematical objects called ``geometries'' and the singular ``geometry'', which he understands as a way of thinking about mathematics. Although the book does not address branches of mathematics and mathematical physics such as Riemannian and Kahler manifolds or, say, differentiable manifolds and conformal field theories, the ideology of category language and transformation groups on which the book is based prepares the reader for the study of, and eventually, research in these important and rapidly developing areas of contemporary mathematics.

Fundamentals of Multiphase Flow

Fundamentals of Multiphase Flow PDF Author: Christopher E. Brennen
Publisher: Cambridge University Press
ISBN: 9780521848046
Category : Science
Languages : en
Pages : 376

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Book Description
Publisher Description

Droplet Wetting and Evaporation

Droplet Wetting and Evaporation PDF Author: David Brutin
Publisher: Academic Press
ISBN: 0128008083
Category : Science
Languages : en
Pages : 464

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Book Description
Droplet Wetting and Evaporation provides engineers, students, and researchers with the first comprehensive guide to the theory and applications of droplet wetting and evaporation. Beginning with a relevant theoretical background, the book moves on to consider specific aspects, including heat transfer, flow instabilities, and the drying of complex fluid droplets. Each chapter covers the principles of the subject, addressing corresponding practical issues and problems. The text is ideal for a broad range of domains, from aerospace and materials, to biomedical applications, comprehensively relaying the challenges and approaches from the different communities leading the way in droplet research and development. - Provides a broad, cross-subject coverage of theory and application that is ideal for engineers, students and researchers who need to follow all major developments in this interdisciplinary field - Includes comprehensive discussions of heat transfer, flow instabilities, and the drying of complex fluid droplets - Begins with an accessible summary of fundamental theory before moving on to specific areas such as heat transfer, flow instabilities, and the drying of complex fluid droplets

Physics Briefs

Physics Briefs PDF Author:
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 954

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Book Description


Interfacial Convection in Multilayer Systems

Interfacial Convection in Multilayer Systems PDF Author: A. Nepomnyashchy
Publisher: Springer Science & Business Media
ISBN: 0387877134
Category : Mathematics
Languages : en
Pages : 509

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Book Description
This book gives a systematic investigation of convection in systems comprised of liquid layers with deformatable interfaces. This new edition includes completely updated and new material on flows in ultra thin films and brings up to date progress made in the technology on micro and nano scales. Also, this revised edition will reflect progress in the dynamics of complex fluids.

Microscale Surface Tension and Its Applications

Microscale Surface Tension and Its Applications PDF Author: Pierre Lambert
Publisher: MDPI
ISBN: 3039215647
Category : Technology & Engineering
Languages : en
Pages : 240

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Book Description
Building on advances in miniaturization and soft matter, surface tension effects are a major key to the development of soft/fluidic microrobotics. Benefiting from scaling laws, surface tension and capillary effects can enable sensing, actuation, adhesion, confinement, compliance, and other structural and functional properties necessary in micro- and nanosystems. Various applications are under development: microfluidic and lab-on-chip devices, soft gripping and manipulation of particles, colloidal and interfacial assemblies, fluidic/droplet mechatronics. The capillary action is ubiquitous in drops, bubbles and menisci, opening a broad spectrum of technological solutions and scientific investigations. Identified grand challenges to the establishment of fluidic microrobotics include mastering the dynamics of capillary effects, controlling the hysteresis arising from wetting and evaporation, improving the dispensing and handling of tiny droplets, and developing a mechatronic approach for the control and programming of surface tension effects. In this Special Issue of Micromachines, we invite contributions covering all aspects of microscale engineering relying on surface tension. Particularly, we welcome contributions on fundamentals or applications related to: Drop-botics: fluidic or surface tension-based micro/nanorobotics: capillary manipulation, gripping, and actuation, sensing, folding, propulsion and bio-inspired solutions; Control of surface tension effects: surface tension gradients, active surfactants, thermocapillarity, electrowetting, elastocapillarity; Handling of droplets, bubbles and liquid bridges: dispensing, confinement, displacement, stretching, rupture, evaporation; Capillary forces: modelling, measurement, simulation; Interfacial engineering: smart liquids, surface treatments; Interfacial fluidic and capillary assembly of colloids and devices; Biological applications of surface tension, including lab-on-chip and organ-on-chip systems.

Fluid Interfaces

Fluid Interfaces PDF Author: Eduardo Guzmán
Publisher: MDPI
ISBN: 3039436333
Category : Science
Languages : en
Pages : 232

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Book Description
Fluid interfaces are promising candidates for confining different types of materials, e.g., polymers, surfactants, colloids, and even small molecules, to be used in designing new functional materials with reduced dimensionality. The development of such materials requires a deepening of the physicochemical bases underlying the formation of layers at fluid interfaces as well as on the characterization of their structures and properties. This is of particular importance because the constraints associated with the assembly of materials at the interface lead to the emergence of equilibrium and features of dynamics in the interfacial systems, which are far removed from those conventionally found in traditional materials. This Special Issue is devoted to studies on the fundamental and applied aspects of fluid interfaces, and attempts to provide a comprehensive perspective on the current status of the research field.

Transport Phenomena in Multiphase Systems

Transport Phenomena in Multiphase Systems PDF Author: Amir Faghri
Publisher: Academic Press
ISBN:
Category : Multiphase flow
Languages : en
Pages : 1072

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Book Description
Engineering students in a wide variety of engineering disciplines from mechanical and chemical to biomedical and materials engineering must master the principles of transport phenomena as an essential tool in analyzing and designing any system or systems wherein momentum, heat and mass are transferred. This textbook was developed to address that need, with a clear presentation of the fundamentals, ample problem sets to reinforce that knowledge, and tangible examples of how this knowledge is put to use in engineering design. Professional engineers, too, will find this book invaluable as reference for everything from heat exchanger design to chemical processing system design and more. * Develops an understanding of the thermal and physical behavior of multiphase systems with phase change, including microscale and porosity, for practical applications in heat transfer, bioengineering, materials science, nuclear engineering, environmental engineering, process engineering, biotechnology and nanotechnology * Brings all three forms of phase change, i.e., liquid vapor, solid liquid and solid vapor, into one volume and describes them from one perspective in the context of fundamental treatment * Presents the generalized integral and differential transport phenomena equations for multi-component multiphase systems in local instance as well as averaging formulations. The molecular approach is also discussed with the connection between microscopic and molecular approaches * Presents basic principles of analyzing transport phenomena in multiphase systems with emphasis on melting, solidification, sublimation, vapor deposition, condensation, evaporation, boiling and two-phase flow heat transfer at the micro and macro levels * Solid/liquid/vapor interfacial phenomena, including the concepts of surface tension, wetting phenomena, disjoining pressure, contact angle, thin films and capillary phenomena, including interfacial balances for mass, species, momentum, and energy for multi-component and multiphase interfaces are discussed * Ample examples and end-of-chapter problems, with Solutions Manual and PowerPoint presentation available to the instructors