Download or read book The Modelling of Particle Resuspension in a Turbulent Boundary Layer written by Fan Zhang and published by . This book was released on 2011 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle Resuspension and Associated Coherent Structures in a Turbulent Boundary Layer written by David Alan Braaten and published by . This book was released on 1988 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particles in Wall Bounded Turbulent Flows Deposition Re Suspension and Agglomeration written by Jean-Pierre Minier and published by Springer. This book was released on 2016-07-26 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents an up-to-date review of turbulent two-phase flows with the dispersed phase, with an emphasis on the dynamics in the near-wall region. New insights to the flow physics are provided by direct numerical simuation and by fine experimental techniques. Also included are models of particle dynamics in wall-bounded turbulent flows, and a description of particle surface interactions including muti-layer deposition and re-suspension.
Download or read book Introducing Surface Roughness to a Stochastic and Rock N Roll Models to Describe Particle Resuspension in Turbulent Flows written by David Ben Shlomo and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resuspension phenomenon plays an important role in various environmental and industrial implications. Here we generalize a stochastic resuspension model (Fu et al., 2013) by incorporating a phenomenological adhesion model, which accounts for surface roughness (Rabinovich et al., 2000a) instead of its original interaction model that constructed to smooth surfaces to provide a more realistic description of resuspension. Within this framework, we investigate the influence of stochasticity on the resuspended fraction and explore its dependence on particle size and surface roughness. Our findings show that introducing roughness into a stochastic resuspension scheme results in an increase of the resuspended fraction by an order of magnitude. Additionally, our results underscore the contribution of stochasticity in the resuspension process, in which the noise term enables the inclusion of important but less frequent events that contribute to the resuspension probabilities. We show that the stochastic model displays relatively good agreement with experimental data for different particle sizes, albeit some deviations are observed at low friction velocities. Interestingly, the widely used deterministic Rock'n'Roll model (Reeks & Hall, 2001) presents poor agreement with measurements. However, modifying it by replacing its underlying adhesion scheme through the introduction of roughness, as in the stochastic model, results with a significant improvement in the reconstruction of experimental data, yet to lesser extent compared to the stochastic description.
Download or read book Particle Resuspension from a Multy layer Deposit by Turbulent Flow written by Antoine Fromentin and published by . This book was released on 1989 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle resuspension from a multi layer deposit by turbulent flow written by Antoine Fromentin and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle Resuspension from a Multi layer Deposit by Turbulent Flow written by Antoine Fromentin and published by . This book was released on 1989 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precipitation Scavenging And Atmosphere Surface Exchange written by Stephen Schwartz and published by CRC Press. This book was released on 1992-06-01 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: This three-volume set contains selected papers arising from a conference held in 1991 on precipitation and air pollution. The first volume addresses the precipitation scavenging process; the second deals with atmosphere-surface exchange processes; and the third covers air pollution and deposition.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1990 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Particle Adhesion and Removal written by K. L. Mittal and published by John Wiley & Sons. This book was released on 2015-02-02 with total page 573 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides a comprehensive and easily accessible reference source covering all important aspects of particle adhesion and removal. The core objective is to cover both fundamental and applied aspects of particle adhesion and removal with emphasis on recent developments. Among the topics to be covered include: 1. Fundamentals of surface forces in particle adhesion and removal. 2. Mechanisms of particle adhesion and removal. 3. Experimental methods (e.g. AFM, SFA,SFM,IFM, etc.) to understand particle-particle and particle-substrate interactions. 4. Mechanics of adhesion of micro- and nanoscale particles. 5. Various factors affecting particle adhesion to a variety of substrates. 6. Surface modification techniques to modulate particle adhesion. 7. Various cleaning methods (both wet & dry) for particle removal. 8. Relevance of particle adhesion in a host of technologies ranging from simple to ultra-sophisticated.
Download or read book Numerical Simulation of Solid Particle Transport in Atmospheric Boundary layer Over Obstacles written by Gang Huang and published by . This book was released on 2015 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transport of solid particles inside a laboratory-scale turbulent boundary-layer is studied by numerical simulations, to obtain a better understanding of the mechanisms associated with wind erosion of soil. The presence of one or several Gaussian hills allows a study of the topographic effects on the transport, deposition and re-emission of solid particles. The carrier fluid motion is resolved in a Large Eddy Simulation (LES). Wall models are implemented to better account for the effects of turbulent flow near the terrain. Particle trajectories are calculated using a Lagrangian tracking. Take-off and rebound models are developed in order to take into account particle emissions and impacts at the wall. In the first part, the flow over transversal Gaussian hills is simulated and validated by comparison with different experiments. According to Oke [1988], the flow inside an urban canopy can be schematically characterised into different flow regimes depending on the relative localisation of the obstacles at the ground. This concept is applied to the case of sand dunes, assimilated to 2D hills in this study. The focus is on the recirculation zone (RZ) on the lee side, which has the characteristic of increasing the residence time and the interaction fluid/particle in general, particle trapping and deposition in particular. The variations of RZ with different hill geometries and Reynolds numbers are examined. A study on the roughness sublayer is conducted in order to determine the roughness effects due to the layer of solid particles on the wall. The second part of the work is devoted to the simulation of solid particle transport over the Gaussian hills. The objective is to improve the modelling of particle take-off, rebound and the two-way coupling between the fluid and the particle. A first work of validation is conducted by using the complete model of solid particle transport developed in this thesis. In particular, the evolution of particle emission flux predicted by the take-off model is in accordance with classical saltation models and experiments from the literature. Over the Gaussian hills, analysis of particle transport is conducted using concentration and mean velocity fields. Two mappings are realised. The first indicates the intensity of the local and instantaneous flow structures that arguably regulate the re-entrainment of particles trapped inside the RZ. The second shows the accumulation of particles on the wall. These results highlight zones prone to wind erosion and particle deposition around the hills. Last but not least, the fluxes of particle trapping and deposition inside the RZ are quantified and compared to the incoming flux from upstream. These fluxes, albeit relatively weak in comparison to the incoming one, contribute potentially to dune migrations and desertification.
Download or read book Multiphase Flow Handbook Second Edition written by Efstathios Michaelides and published by CRC Press. This book was released on 2016-10-26 with total page 1559 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Multiphase Flow Handbook, Second Edition is a thoroughly updated and reorganized revision of the late Clayton Crowe’s work, and provides a detailed look at the basic concepts and the wide range of applications in this important area of thermal/fluids engineering. Revised by the new editors, Efstathios E. (Stathis) Michaelides and John D. Schwarzkopf, the new Second Edition begins with two chapters covering fundamental concepts and methods that pertain to all the types and applications of multiphase flow. The remaining chapters cover the applications and engineering systems that are relevant to all the types of multiphase flow and heat transfer. The twenty-one chapters and several sections of the book include the basic science as well as the contemporary engineering and technological applications of multiphase flow in a comprehensive way that is easy to follow and be understood. The editors created a common set of nomenclature that is used throughout the book, allowing readers to easily compare fundamental theory with currently developing concepts and applications. With contributed chapters from sixty-two leading experts around the world, the Multiphase Flow Handbook, Second Edition is an essential reference for all researchers, academics and engineers working with complex thermal and fluid systems.
Download or read book Numerical Investigation of Particle Deposition in a Turbulent Boundary Layer with Forced Turbulence in the External Flow written by Manoj Joishi and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deposition of particles on a wall plays a significant role in fluid-solid processes such as inclusions recovery from liquid steel in ladle furnace, that controls inclusion cleanliness upstream from solidification. The aim of this work is to study the turbulent deposition and capture of particles on a wall, in a situation where turbulence in the boundary layer originates both from wall shear and from agitation in the external flow. In a ladle furnace, such an agitation would result from bubble injection. A framework for simulations at mesoscopic scale in which particles are represented as points but the turbulence is fully resolved has been developped using an in-house solver, where a Lattice Boltzmann Method (LBM) solves flow dynamics and linear isotropic forcing generates artificial turbulence. Lagrangian Particle Tracking (LPT) is used to achieve one way coupling between particle motions and turbulent flow. These numerical methods were applied to Direct Numerical simulation (DNS) of a fully developed turbulent boundary layer in which particles smaller than the Kolmogorov length scale are introduced. The deposition mechanisms in aerosol conditions have been analyzed and quantified into a statistical law for deposition velocity in terms of Stokes number, and validated against data from the literature. Such simulations have provided a better understanding of deposition and capture mechanisms, depending on the turbulent flow in a wall boundary layer and on particle physical properties. Also, preliminary simulations in hydrosol conditions that match actual ladle operation have shown that the framework developed in this work can be applied to investigate inclusion behavior in secondary steel-making although statistical analysis in this work focused on aerosols.
Download or read book Dispersion and Deposition of Heavy Particles in Turbulent Flows written by Chunyu Jin and published by . This book was released on 2012 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Developments in Surface Contamination and Cleaning Types of Contamination and Contamination Resources written by Rajiv Kohli and published by William Andrew. This book was released on 2016-11-21 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developments in Surface Contamination and Cleaning, Volume Ten, provides a state-of-the-art guide to the current knowledge on the behavior of film-type and particulate surface contaminants and their cleaning methods. This newest volume in the series discusses mechanisms of particle adhesion, particle behavior in liquid systems, and metallic contamination and its impact. In addition, the book includes a discussion of the types of contaminants, with resources to deal with them and information on environmental issues related to surface contamination and cleaning. Taken as a whole, the series forms a unique reference for professionals and academics working in the area of surface contamination and cleaning that also includes information on cleaning at the micro and nano scales. Written by established experts in the contamination field that provide an authoritative resource Presents a comprehensive review of new trends in contaminants and resources for dealing with those contaminants Contains detailed case studies to illustrate various scenarios
Download or read book Ash Pulverized Coal Deposition in Combustors Gasifiers written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Further progress in achieving the objectives of the project was made in the period of July 1 to September 30, 1997. The direct numerical simulation of particle removal process in turbulent gas flows was continued. Variations of vorticity contours which are averaged over a short time duration are studied. It is shown that the near wall vortices profoundly affect the particle removal process in turbulent boundary layer flows. The sublayer model for evaluating the particle deposition in turbulent flows was extended to include the effect of particle rebound. A new more advance flow model for the near wall vortices is also used in these analysis. Sample particle trajectories are obtained and discussed. Experimental data for transport and deposition of fibrous particles in the aerosol wind tunnel was obtained. The measured deposition velocity is compared with the empirical correlation and the available data and discussed. Particle resuspension process in turbulent flows are studied. The model is compared with the experimental data. It is shown that when the effects of the near wall flow structure, as well as the surface roughness are included the model agrees with the available experimental data.
Download or read book Particle Resuspension from Surfaces in Turbulent Flow written by Gennady Ziskind and published by . This book was released on 1993 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
