Download or read book Models for Liquid Droplet Dynamics written by Sanjay Kumar Khattri and published by . This book was released on 2003 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Droplets written by Arnold Frohn and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book deals with the dynamical behaviour of single droplets and regular droplet systems. It has been written mainly for experimental researchers. After a short description of the theoretical background, the different experimental facilities and methods necessary for the investigation of single droplets are described in detail. A summary of important applications is included.
Download or read book Fluid Dynamics and Transport of Droplets and Sprays written by W. A. Sirignano and published by Cambridge University Press. This book was released on 2010-01-11 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the theoretical foundations of spray and droplet applications relevant to the technology for active control of sprays applied to new products and applications, improved product performance, cost reductions, and improved environmental outcomes. It also covers theory related to power and propulsion; materials processing and manufacturing technologies including droplet-based net form processing, coating, and painting; medication; pesticides and insecticides; and other consumer uses.
Download or read book Droplet Dynamics Under Extreme Ambient Conditions written by Kathrin Schulte and published by Springer Nature. This book was released on 2022 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book presents the main results of the Collaborative Research Center SFB-TRR 75, which spanned the period from 2010 to 2022. Scientists from a variety of disciplines, ranging from thermodynamics, fluid mechanics, and electrical engineering to chemistry, mathematics, computer science, and visualization, worked together toward the overarching goal of SFB-TRR 75, to gain a deep physical understanding of fundamental droplet processes, especially those that occur under extreme ambient conditions. These are, for example, near critical thermodynamic conditions, processes at very low temperatures, under the influence of strong electric fields, or in situations with extreme gradients of boundary conditions. The fundamental understanding is a prerequisite for the prediction and optimisation of engineering systems with droplets and sprays, as well as for the prediction of droplet-related phenomena in nature. The book includes results from experimental investigations as well as new analytical and numerical descriptions on different spatial and temporal scales. The contents of the book have been organised according to methodological fundamentals, phenomena associated with free single drops, drop clusters and sprays, and drop and spray phenomena involving wall interactions.
Download or read book Modelling of Liquid Droplet Dynamics in a High DC Magnetic Field written by Stuart Easter and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The oscillating droplet technique is an experimental technique that is used to measure the surface tension and viscous damping coefficients of a liquid droplet. This technique has been the subject of much analysis; theoretical, numerical, and experimental with a number of different external forces used to confine the droplet. These external forces are found to modify the oscillation frequency and damping rates, which need to be quantified in order for the measurement technique to be used. The dynamics of the droplet are three-dimensional but previous numerical work has largely focused on axisymmetric cases. This work uses numerical techniques to extend the previous analysis to include the full three-dimensional effects. In this work a three-dimensional numerical model is designed, developed and applied to study the dynamics of a liquid droplet both in free space and with a high DC magnetic field used to balance gravitational forces. The numerical model is a grid point formulation of the pseudo-spectral collocation method discretised in a spherical coordinate system with the implicit Euler method used to advance the solution in time. A coordinate transformation method is used to ensure the direct surface tracking required for modelling the surface shape oscillations. The study covers the laminar fluid flow regime within a droplet exhibiting translational and surface shape oscillations providing a greater understanding of the physical behaviour of the droplet along with a qualitative and quantitative comparison with theoretical results. Initially a droplet oscillating in free space is considered, with a range of surface oscillation modes used to demonstrate the three-dimensional dynamics. Then the influence of electromagnetic forces on a diamagnetic droplet is studied, this includes the field from a solenoid magnet used to levitate a diamagnetic droplet. Finally the dynamics of an electrically conducting droplet in an external static magnetic field are modelled. In each case a number of methods are used to analyse the surface displacement in order to determine the surface tension and viscous damping coefficients. The numerical study of a freely oscillating droplet shows good agreement with the low order theoretical results for droplets in the limit of low viscosity. The high accuracy of the surface tracking method allows the non-linear effects of mode coupling and frequency shift with amplitude to be observed. There is good agreement with the theoretical values available for inviscid axisymmetric oscillations and the numerical study provides the opportunity to determine these effects for three-dimensional viscous oscillations. The magnetic field from a solenoid is used to study the levitation of a diamagnetic droplet and the oscillation frequencies of the droplet are compared with a theoretical model. The magnetic field is analysed and the accuracy of the field calculation used when determining the modification to the oscillation frequencies is considered with the use of a theoretical model. Analysis is made into the splitting of the frequency spectrum due to the magnetic field. The theoretical model that is available for an electrically conducting droplet in a static magnetic field predicts different fluid flow within the droplet and oscillation frequency and damping rate changes. These changes are compared qualitatively and quantitatively with the numerical model results with good agreement.
Download or read book Modeling Sessile Droplet Dynamics in Channel Flow written by Amirreza Golpaygan and published by . This book was released on 2007 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamics of a sessile droplet in channel flow is studied numerically. The numerical model uses one set of the governing equations combined with a volume tracking method on a fixed structured mesh to model the simultaneous movement of mass and momentum across cell boundaries. Surface tension is modeled as a body force acting on the fluid near the free surface. Two dimensional sessile droplet deformation and channel flow structures are discussed for both pinned and unpinned droplets. The effects of having a fixed contact line on the deformation and breakup of a droplet are investigated. A characteristic length is defined to compare droplet deformation due to changes in the surface tension, viscosity and density ratios. Among theses parameters, the surface tension is found to be the most important one in determining the mobility of the droplets. A breakup criterion is obtained in terms of droplet Reynolds and Capillary numbers. Next, dynamics of two spaced sessile droplets in a channel flow is investigated. Displacements of binary droplets in a channel flow are compared by studying changes in the location of the leading and trailing edges for each droplet at different droplet spacing. Deformation and displacement of leading and tailing droplets with the ones for a single droplet are presented. The thesis concludes with application of the model to study displacement of a three-dimensional droplet. Dynamics of channel flow at the presence of water droplet was investigated considering the effects of Reynolds Number, Capillary number, Bond number, droplet size, and the contact angle. Displacement was characterized based on the changes of the droplet height and the contact wetted area.
Download or read book Drop Dynamics and Dropwise Condensation on Textured Surfaces written by Sameer Khandekar and published by Springer Nature. This book was released on 2020-09-11 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an expanded form of the monograph, Dropwise Condensation on Inclined Textured Surfaces, Springer, 2013, published earlier by the authors, wherein a mathematical model for dropwise condensation of pure vapor over inclined textured surfaces was presented, followed by simulations and comparison with experiments. The model factored in several details of the overall quasi-cyclic process but approximated those at the scale of individual drops. In the last five years, drop level dynamics over hydrophobic surfaces have been extensively studied. These results can now be incorporated in the dropwise condensation model. Dropwise condensation is an efficient route to heat transfer and is often encountered in major power generation applications. Drops are also formed during condensation in distillation devices that work with diverse fluids ranging from water to liquid metals. Design of such equipment requires careful understanding of the condensation cycle, starting from the birth of nuclei, followed by molecular clusters, direct growth of droplets, their coalescence, all the way to instability and fall-off of condensed drops. The model described here considers these individual steps of the condensation cycle. Additional discussions include drop shape determination under static conditions, a fundamental study of drop spreading in sessile and pendant configurations, and the details of the drop coalescence phenomena. These are subsequently incorporated in the condensation model and their consequences are examined. As the mathematical model is spread over multiple scales of length and time, a parallelization approach to simulation is presented. Special topics include three-phase contact line modeling, surface preparation techniques, fundamentals of evaporation and evaporation rates of a single liquid drop, and measurement of heat transfer coefficient during large-scale condensation of water vapor. We hope that this significantly expanded text meets the expectations of design engineers, analysts, and researchers working in areas related to phase-change phenomena and heat transfer.
Download or read book Physics and Chemistry of Interfaces written by Hans-Jürgen Butt and published by John Wiley & Sons. This book was released on 2023-02-07 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physics and Chemistry of Interfaces Comprehensive textbook on the interdisciplinary field of interface science, fully updated with new content on wetting, spectroscopy, and coatings Physics and Chemistry of Interfaces provides a comprehensive introduction to the field of surface and interface science, focusing on essential concepts rather than specific details, and on intuitive understanding rather than convoluted math. Numerous high-end applications from surface technology, biotechnology, and microelectronics are included to illustrate and help readers easily comprehend basic concepts. The new edition contains an increased number of problems with detailed, worked solutions, making it ideal as a self-study resource. In topic coverage, the highly qualified authors take a balanced approach, discussing advanced interface phenomena in detail while remaining comprehensible. Chapter summaries with the most important equations, facts, and phenomena are included to aid the reader in information retention. A few of the sample topics included in Physics and Chemistry of Interfaces are as follows: Liquid surfaces, covering microscopic picture of a liquid surface, surface tension, the equation of Young and Laplace, and curved liquid surfaces Thermodynamics of interfaces, covering surface excess, internal energy and Helmholtz energy, equilibrium conditions, and interfacial excess energies Charged interfaces and the electric double layer, covering planar surfaces, the Grahame equation, and limitations of the Poisson-Boltzmann theory Surface forces, covering Van der Waals forces between molecules, macroscopic calculations, the Derjaguin approximation, and disjoining pressure Physics and Chemistry of Interfaces is a complete reference on the subject, aimed at advanced students (and their instructors) in physics, material science, chemistry, and engineering. Researchers requiring background knowledge on surface and interface science will also benefit from the accessible yet in-depth coverage of the text.
Download or read book Dynamics of a Liquid Droplet written by Prashant Khare and published by American Chemical Society. This book was released on 2024-04-09 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiphase flows and droplet dynamics play a vital role in the industry. Mineral ore (i.e., iron, aluminum, and copper mined in huge quantities yearly) must flow at some stage during extraction. Fluidized beds, bubbly flow in nuclear reactors, inkjet printing, gas-particle flows in chemical reactors, cavitating pumps and turbines, electrophotography used in copy machines, and laser and LED printers are a few examples of process technologies where multiphase flows play a vital role. The importance of multiphase flows concerning air pollution has recently been well recognized. In particular, in propulsion devices, such as automobiles and gas turbine engines in aircraft and power plants, the combustion of liquid fuels, such as diesel, gasoline, and Jet-A, is responsible for creating greenhouse gases and particulates (e.g., unburned carbon particles), which are identified as pollutants. The efficiency of the combustion process and, consequently, the production of the resulting pollutants are dictated by the breakup and vaporization of liquid fuels, making understanding these phenomena critical to developing efficient combustion devices. This ACS In Focus digital primer discusses the current understanding of the breakup and vaporization of single droplets in stagnant and convective environments. Its intended audience is an early career researcher (ranging from a second-year Ph.D. student to a postdoctoral fellow) interested in exploring the fascinating world of liquid droplets. The reader is expected to have had at least an advanced thermodynamics and fluid mechanics undergraduate course.
Download or read book Geometric Methods in Physics XXXVII written by Piotr Kielanowski and published by Springer Nature. This book was released on 2019-11-26 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book consists of articles based on the XXXVII Białowieża Workshop on Geometric Methods in Physics, 2018. The series of Białowieża workshops, attended by a community of experts at the crossroads of mathematics and physics, is a major annual event in the field. This edition of the workshop featured a special session dedicated to Professor Daniel Sternheimer on the occasion of his 80th birthday. The previously unpublished papers present cutting-edge current research, typically grounded in geometry and analysis, with applications to classical and quantum physics. For the past seven years, the Białowieża Workshops have been complemented by a School on Geometry and Physics comprising a series of advanced lectures for graduate students and early-career researchers. The book also includes abstracts of the five lecture series that were given at the seventh school.
Download or read book The Finite Element Method Solid mechanics written by O. C. Zienkiewicz and published by Butterworth-Heinemann. This book was released on 2000 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Droplets and Sprays Simple Models of Complex Processes written by Sergei S. Sazhin and published by Springer Nature. This book was released on 2022-06-28 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book acts as a guide to simple models that describe some of the complex fluid dynamics, heat/mass transfer and combustion processes in droplets and sprays. Attention is focused mainly on the use of classical hydrodynamics, and a combination of kinetic and hydrodynamic models, to analyse the heating and evaporation of mono- and multi-component droplets. The models were developed for cases when small and large numbers of components are present in droplets. Some of these models are used for the prediction of time to puffing/micro-explosion of composite water/fuel droplets — processes that are widely used in combustion devices to stimulate disintegration of relatively large droplets into smaller ones. The predictions of numerical codes based on these models are validated against experimental results where possible. In most of the models, droplets are assumed to be spherical; some preliminary results of the generalisation of these models to the case of non-spherical droplets, approximating them as spheroids, are presented.
Download or read book Aerosol Filtration written by Dominique Thomas and published by Elsevier. This book was released on 2016-11-30 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filtration of aerosols is omnipresent in our daily lives, in areas as diverse as health, the protection of people and the environment, and air treatment inside buildings. However, the collection of particles within a filter media is not, contrary to popular belief, linked to a simple screen effect. The phenomena involved are much more complex and require the consideration of aerosol interactions, filter media and process conditions to select the best fiber filter for a given application. Aerosol Filtration, book for students, hygiene or process engineers, fibrous media manufacturers, designers, and filtration system suppliers or users addresses the filtration of aerosols in six chapters. These chapters cover physics and aerosol characterization, the fibrous media, and efficiency and filter clogging by solid or liquid aerosols, with special attention to the filtration of the nanoparticles. Analyses the behavior of fibrous media against solid and liquid aerosols Presents models of efficiency and pressure drop Introduces computing elements for estimating the lifetime of filters Provides guidance for designing filters and predicting their behavior over time
Download or read book Simulation of Liquid Droplet in Air and on a Solid Surface written by Kevin Launglucknavalai and published by . This book was released on 2013 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although multiphase gas and liquid phenomena occurs widely in engineering problems, many aspects of multiphase interaction like within droplet dynamics are still not quantified. This study aims to qualify the Lattice Boltzmann (LBM) Interparticle Potential multiphase com- putational method in order to build a foundation for future multiphase research. This study consists of two overall sections. The first section in Chapter 2 focuses on understanding the LBM method and Interparti- cle Potential model. It outlines the LBM method and how it relates to macroscopic fluid dynamics. The standard form of LBM is obtained. The perturbation solution obtaining the Navier-Stokes equations from the LBM equation is presented. Finally, the Interparticle Potential model is incorporated into the numerical LBM method. The second section in Chapter 3 presents the verification and validation cases to confirm the behavior of the single-phase and multiphase LBM models. Experimental and analytical results are used briefly to compare with numerical results when possible using Poiseuille channel flow and flow over a cylinder. While presenting the numerical results, practical considerations like converting LBM scale variables to physical scale variables are considered. Multiphase results are verified using Laplaces law and artificial behaviors of the model are explored. In this study, a better understanding of the LBM method and Interparticle Potential model is gained. This allows the numerical method to be used for comparison with experimental results in the future and provides a better understanding of multiphase physics overall.
Download or read book Modeling Axisymmetric Flows written by Stanley Middleman and published by Academic Press. This book was released on 1995-08-14 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: This concise book is intended to fulfill two purposes: to provide an important supplement to classic texts by carrying fluid dynamics students on into the realm of free boundary flows; and to demonstrate the art of mathematical modeling based on knowledge, intuition, and observation. In the authors words, the overall goal is make the complex simple, without losing the essence--the virtue--of the complexity. Modeling Axisymmetric Flows: Dynamics of Films, Jets, and Drops is the first book to cover the topics of axisymmetric laminar flows; free-boundary flows; and dynamics of drops, jets, and films. The text also features comparisons of models to experiments, and it includes a large selection of problems at the end of each chapter. Contains problems at the end of each chapter Compares real-world experimental data to theory Provides one of the first comprehensive examinations of axisymmetric laminar flows, free-boundary flows, and dynamics of drops, jets, and films Includes development of basic equations Written in a style suitable for use as a textbook
Download or read book Drop Surface Interactions written by Martin Rein and published by Springer. This book was released on 2014-05-04 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive overview of fluid mechanical, thermal and physico-chemical aspects of drop-surface interactions. Basic physical mechanisms pertaining to free-surface flow phenomena characteristic of drop impact on solid and liquid surfaces are explained emphasizing the importance of scaling. Moreover, physico-chemical fundamentals relating to a forced spreading of complex solutions, analytical tools for calculating compressibility effects, and heat transfer and phase change phenomena occurring during solidification and evaporation processes, respectively, are introduced in detail. Finally, numerical approaches particularly suited for modeling drop-surface interactions are consisely surveyed with a particular emphasis on boundary integral methods and Navier-Stokes algorithms (volume of fluid, level set and front tracking algorithms). The book is closed by contributions to a workshop on Drop-Surface Interactions held at the International Centre of Mechanical Sciences.
Download or read book On Computational Modeling of Dynamic Drop surface Interactions During Post impact Spreading of Water and Aqueous Surfactant Solution written by Shrikant A. Bokil and published by . This book was released on 2013 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the present work is to develop a computational model to simulate liquid droplet impact and post-impact spread-recoil dynamics on a horizontal, flat, smooth, dry surface. The governing equations of continuity and momentum are solved to simulate the transient flow. Volume of Fluid (VOF) method is applied to capture continuously deforming gas-liquid interface. Simulations are carried out for pure water and aqueous solution of Sodium Dodecyl Sulphate (SDS) droplet impact on a hydrophobic (Teflon) surface. Simulations are carried out for Weber number 20 and 80 with impact velocities of 0.7 m/s and 1.4 m/s and droplet diameters of 2 mm and 3 mm, respectively. The results show increase in maximum spreading factor with increase in Weber number. Computational results predict advancing, recoiling and bouncing behavior of water droplets on the Teflon surface which agrees with the experimental observations available in literature. Aqueous solution of Sodium Dodecyl Sulphate (SDS) at twice the Critical Micelle Concentration (2xCMC) is used and its time and space dependent surface tension behavior is modeled. It is observed that dynamic surface tension plays a primary role in the modification of droplet spread-recoil process. The simulation results for surfactant solution show larger drop spread followed by weaker recoil and no rebound from the surface. These results are validated with experimental measurements reported in the literature. Non-isothermal impact conditions are investigated to study heat transfer phenomenon during droplet impact. The solid surface is maintained at 353°K and corresponding heat flux values and overall heat transfer rates for both pure water and surfactant solution drops are calculated. The results indicate that aqueous surfactant solution improves the liquid-solid wetting area and results in higher heat transfer compared to pure water droplet.
