Download or read book Numerical Study of Particle and Droplet Interactions written by Lisa Prahl and published by . This book was released on 2006 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiphase Flows with Droplets and Particles Third Edition written by Efstathios E. Michaelides and published by CRC Press. This book was released on 2022-12-30 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiphase Flows with Droplets and Particles provides an organized, pedagogical study of multiphase flows with particles and droplets. This revised edition presents new information on particle interactions, particle collisions, thermophoresis and Brownian movement, computational techniques and codes, and the treatment of irregularly shaped particles. An entire chapter is devoted to the flow of nanoparticles and applications of nanofluids. Features Discusses the modelling and analysis of nanoparticles. Covers all fundamental aspects of particle and droplet flows. Includes heat and mass transfer processes. Features new and updated sections throughout the text. Includes chapter exercises and a Solutions Manual for adopting instructors. Designed to complement a graduate course in multiphase flows, the book can also serve as a supplement in short courses for engineers or as a stand-alone reference for engineers and scientists who work in this area.
Download or read book Drop Surface Interactions written by Martin Rein and published by Springer Science & Business Media. This book was released on 2002-10-30 with total page 328 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 Numerical Simulation of Fluid particle Interactions written by Arindam Dasgupta and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Study of Particle Collection by Single Water Droplets microform written by Kevin R. J. Ellwood and published by National Library of Canada. This book was released on 1987 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Study of Particle Collection By Single Water Droplets written by Shekar Viswanathan and published by . This book was released on 1999 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulation of Near contact Motion and Coalescence of Inertial Droplets in Turbulence written by Melanie Li Sing How and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigate the evolution of the particle size distribution of a coalescing particle field under different conditions in turbulence and the role of hydrodynamic interactions on the coalescing rate for near-contact motion of inertial droplets in quiescent flow. The primary motivation of this work is to understand the evolution of atmospheric clouds. The 10 - 50 microns size range in the cloud droplet growth evolution, often referred to as the 'size gap', is underpredicted by current microphysical models. There is growing consensus that turbulence plays a critical role in accelerating the cloud evolution. The first part of the study was performed using direct numerical simulation (DNS) of an evolving Eulerian fluid velocity field with Lagrangian particle tracking. We present parametric studies of the effects of critical variables on the particle size distribution of an initially monodisperse particle field as it collides and coalesces in turbulence without hydrodynamic interactions. We describe a Collision Optimized Detection Algorithm (CODA), embedded in our DNS turbulence code, to identify and enact particle coalescence in a manner that is optimized for a parallelized architecture. The effects of the particle sub-Kolmorogov size parameter, particle inertia, volume fraction and Reynolds number on the size distribution are systematically investigated. We find that the particle size distribution in turbulence : (i) has an exponential shape in terms of the particle Stokes number, a measure of particle inertia; (ii) has a very weak dependence on Reynolds number; (iii) broadens with decreasing particle Stokes number and decreasing size parameter; and (iv) transitions from an exponential to a power-law behavior at higher volume fractions. In the second part of the study, we investigate the importance of hydrodynamic interactions in near contact motion between the droplets in determining whether a collision leads to molecular contact and coalescence. As the droplets approach, the air in the gap must be squeezed out of the way, which leads to a resistance force that diverges with decreasing gap according to the continuum lubrication theory, preventing contact. At separations on the order of the mean free path of air, the continuum approximation breaks down, and the lubrication flow is described by a non-continuum model. Treating accurately the continuum nature of the gas at the far field and transitioning to a non-continuum model at gap separations comparable to the mean free path of the gas is therefore critical to capture the behavior leading up to contact and eventually coalescence. Building on previous work, which derived a uniformly valid expression for the resistivity to normal motion, we use a similar matched asymptotic expansion technique to derive the uniformly valid resistivity functions for tangential motions. In the third part of the study, we apply the complete set of resistivity functions to a trajectory analysis of droplet pairs settling in quiescent flow to investigate the collision efficiency as a function of the droplet size ratio, Knudsen number and Stokes number. In the near-contact motion, the collision efficiency increases with increasing pairwise droplet inertia and size ratio. It is observed to have a larger dependence on the Knudsen number for lower Stokes numbers, and the curves approach an asymptotic limit for Stokes numbers below 0.1. The collision efficiency for realistic cloud droplets at 50 microns peaks at 0.82. We conclude by discussing the implications of this work for cloud microphysics modeling and suggest next steps for future research.
Download or read book A Numerical Study of Droplet Vortex Interactions in an Evaporating Spray written by and published by . This book was released on 1994 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, we present the time-dependent axisymmetric numerical simulation of an unsteady n-heptane evaporating spray, and investigate the droplet-vortex interactions which determine the structural and dynamic characteristics of a spray jet flow. The spray is formed between a droplet-laden heated nitrogen jet and a coflowing air stream. A detailed, multidimensional, two-phase algorithm is developed for the simulation. A comprehensive vaporization model is employed to calculate the instantaneous droplet size and surface temperature along the trajectory of each droplet group. Monodisperse spray in introduced into the large vortex structures that are generated due to the presence of buoyancy-induced hydrodynamic instability of the heated jet. Results focused on the two-way interactions between vortical structures and droplets, and the dynamics of both non-evaporating and evaporating sprays. The vortex structures cause droplets to disperse radially outward, and this in turn determines the fuel vapor distribution and also modifies the vortex dynamics. Thus, the dynamics and structural characteristics of the evaporating spray are strongly influenced by the two-way transient interactions. The effects of initial droplet size, injection location, and liquid-to-gas mass loading ratio on these interactions are also investigated.
Download or read book Droplet Interactions and Spray Processes written by Grazia Lamanna and published by Springer Nature. This book was released on 2020-03-14 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a selection of contributions to the DIPSI workshop 2019 (Droplet Impact Phenomena & Spray Investigations) as well as recent progress of the Int. Research Training Group “DROPIT”.The DIPSI workshop, which is now at its thirteenth edition, represents an important opportunity to share recent knowledge on droplets and sprays in a variety of research fields and industrial applications. The research training group “DROPIT” is focused on droplet interaction technologies where microscopic effects influence strongly macroscopic behavior. This requires the inclusion of interface kinetics and/or a detailed analysis of surface microstructures. Normally, complicated technical processes cover the underlying basic mechanisms, and therefore, progress in the overall process modelling can hardly be gained. Therefore, DROPIT focuses on the underlying basic processes. This is done by investigating different spatial and/or temporal scales of the problems and by linking them through a multi-scale approach. In addition, multi-physics are required to understand e.g. problems for droplet-wall interactions, where porous structures are involved.
Download or read book Moving Particle Semi implicit Method written by Seiichi Koshizuka and published by Academic Press. This book was released on 2018-06-01 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: Moving Particle Semi-implicit Method: A Meshfree Particle Method for Fluid Dynamics begins by familiarizing the reader with basic theory that supports their journey through sections on advanced MPH methods. The unique insights that this method provides include fluid-structure interaction, non-Newtonian flow, and cavitation, making it relevant to a wide range of applications in the mechanical, structural, and nuclear industries, and in bioengineering. Co-authored by the originator of the MPS method, this book is the most authoritative guide available. It will be of great value to students, academics and researchers in industry. - Presents the differences between MPH and SPH, helping readers choose between methods for different purposes - Provides pieces of computer code that readers can use in their own simulations - Includes the full, extended algorithms - Explores the use of MPS in a range of industries and applications, including practical advice
Download or read book Numerical Study of Particle Interaction at Moderate Reynolds Numbers written by Asim Jadoon and published by . This book was released on 2008 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Droplet Interactions During Combustion of Unsupported Droplet Clusters in Microgravity written by Irina N. Ciobanescu Husanu and published by . This book was released on 2005 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Flowing Matter written by Federico Toschi and published by Springer Nature. This book was released on 2019-09-25 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book, published in the Soft and Biological Matter series, presents an introduction to selected research topics in the broad field of flowing matter, including the dynamics of fluids with a complex internal structure -from nematic fluids to soft glasses- as well as active matter and turbulent phenomena. Flowing matter is a subject at the crossroads between physics, mathematics, chemistry, engineering, biology and earth sciences, and relies on a multidisciplinary approach to describe the emergence of the macroscopic behaviours in a system from the coordinated dynamics of its microscopic constituents. Depending on the microscopic interactions, an assembly of molecules or of mesoscopic particles can flow like a simple Newtonian fluid, deform elastically like a solid or behave in a complex manner. When the internal constituents are active, as for biological entities, one generally observes complex large-scale collective motions. Phenomenology is further complicated by the invariable tendency of fluids to display chaos at the large scales or when stirred strongly enough. This volume presents several research topics that address these phenomena encompassing the traditional micro-, meso-, and macro-scales descriptions, and contributes to our understanding of the fundamentals of flowing matter. This book is the legacy of the COST Action MP1305 “Flowing Matter”.
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 A study of droplet deformation written by Hannah Fry and published by Lulu.com. This book was released on 2012-09-14 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: In both engineering and medical applications it is often useful to use the knowledge of the conditions under which adhering liquid droplets appear, deform and interact with surrounding fluids, in order to either remove or create them. Examples include the de-wetting of aircraft surfaces and the process of injecting glue into the bloodstream in the treatment of aneurysms. In this study, we look at various methods of modelling a particular class of droplets - those attached to a wall in the presence of an external shear flow.
