Download or read book Analysis of Dispersion and Deposition of Small Particles in Isotropic and Sheared Turbulent Flows written by Hadj Ounis and published by . This book was released on 1991 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Particles in Turbulent Flows written by Leonid I. Zaichik and published by John Wiley & Sons. This book was released on 2008-12-04 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: The only work available to treat the theory of turbulent flow with suspended particles, this book also includes a section on simulation methods, comparing the model results obtained with the PDF method to those obtained with other techniques, such as DNS, LES and RANS. Written by experienced scientists with background in oil and gas processing, this book is applicable to a wide range of industries -- from the petrol industry and industrial chemistry to food and water processing.
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 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 Particle Laden Flow written by Bernard Geurts and published by Springer Science & Business Media. This book was released on 2007-10-20 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains a selection of the papers that were presented at the EUROMECH colloquium on particle-laden flow held at the University of Twente in 2006. The multiscale nature of this challenging field motivated the calling of the colloquium and reflects the central importance that the dispersion of particles in a flow has in various geophysical and environmental problems. The spreading of aerosols and soot in the air, the growth and dispersion of plankton blooms in seas and oceans, or the transport of sediment in rivers, estuaries and coastal regions are striking examples.
Download or read book Medical Applications of Colloids written by Egon Matijevic and published by Springer Science & Business Media. This book was released on 2008-12-05 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: The important role of ?nely dispersed matter and surfaces in medicine is not always fully understood and appreciated. Speci?cally, ?ne particles (solid or liquid) in the size range of several nanometers to several micrometers have a tremendous effect on our lives, because they can be bene?cial or detrimental to our well-being. Such particles are present in living bodies as red blood cells or cholesterol crystals in the gall bladder. They are ubiquitous in the environment, where they can cause many diseases, such as asbestosis, silicosis, and black lung disease, but they are also used in diagnostic tests, drug delivery, and numerous other applications. More recently, evidence has become available that drug formulations with active components in a ?nely dispersed state may signi?cantly affect their functionality. Furthermore, with miniaturization of medical instrumentation, the size of the components is necess- ily reduced to colloid or even smaller range. This volume is a collection of several chapters dealing with diverse topics of colloids and surfaces relevant to medical applications. Thus, Siiman describes the use of optical properties of uniform colloidal particles as probes in ?ow cytometry. Giesche focuses on the preparations and properties of exceedingly uniform silica spheres for different uses, such as in chromatography. In modi?ed forms, silica p- ticles with incorporated dyes are employed in diagnostics and those combined with tiny magnetic entities in drug delivery.
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 Stochastic Lagrangian Modeling for Large Eddy Simulation of Dispersed Turbulent Two Phase Flows written by Abdallah Sofiane Berrouk and published by Bentham Science Publishers. This book was released on 2011 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the dispersion and the deposition of inertial particles convected by turbulent flows is a domain of research of considerable industrial interest. Inertial particle transport and dispersion are encountered in a wide range of flow configurations, whether they are of industrial or environmental character. Conventional models for turbulent dispersed flows do not appear capable of meeting the growing needs of chemical, mechanical and petroleum industries in this regard and physical environment testing is prohibitive. Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES) ha.
Download or read book Dispersion of Finite Size Droplets and Solid Particles in Isotropic Turbulence written by Michele Rosso and published by . This book was released on 2016 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent disperse two-phase flows, of either fluid/fluid or fluid/solid type, are common in natural phenomena and engineering devices. Notable examples are atmospheric clouds, i.e. dispersed liquid water droplets and ice particles in a complex turbulent flow, and spray of fuel droplets in the combustion chamber of internal combustion engines. However, the physics of the interaction between a dispersed phase and turbulence is not yet fully understood. The objective of this study is to compare the dispersion of deformable finite size droplets with that of solid particles in a turbulent flow in the absence of gravity, by performing Direct Numerical Simulation (DNS). The droplets and the particles have the same diameter, of the order of the Taylor's microscale of turbulence, and the same density ratio to the carrier flow. The solid particle-laden turbulence is simulated by coupling a standard projection method with the Immersed Boundary Method (IBM). The solid particles are fully resolved in space and time without considering particle/particle collisions (two-way coupling). The liquid droplet-laden turbulence is simulated by coupling a variable-density projection method with the Accurate Conservative Level Set Method (ACLSM). The effect of the surface tension is accounted for by using the Ghost Fluid Method (GFM) in order to avoid any numerical smearing, while the discontinuities in the viscous term of the Navier-Stokes equation are smoothed out via the Continuum Surface Force approach. Droplet/droplet interactions are allowed (four-way coupling). The results presented here show that in isotropic turbulence the dispersion of liquid droplets in a given direction is larger than that of solid particles due to the reduced decay rate of turbulence kinetic energy via the four-way coupling effects of the droplets.
Download or read book Turbulent Aerosol Deposition in Large and Small Square Flow Passages written by William Dwight Gerstler and published by . This book was released on 2000 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tracking and Pair Dispersion Analysis of Buoyant Particles in a Turbulent Shear Flow written by Stephanie Paustian and published by . This book was released on 2015 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented are experimental measurements of one and two-particle dispersion in a turbulent shear flow. The baseline flow is a well-characterized high Reynolds number turbulent submerged round jet. Buoyant air bubbles and canola oil droplets were injected into the jet within the self-similar region at five injection locations and five jet Reynolds numbers ranging from 18,000 to 34,000. Images of two particles, injected simultaneously, were obtained from high-speed shadowgraphy. The particles were then tracked using a four-frame predictive algorithm. The influence of mean shear and turbulent fluctuations on dispersion is analyzed for initial positions where a mean velocity shear is superimposed on turbulent fluctuations. The results were analyzed to determine the influence of the density ratio, the non-dimensional shear rate, Reynolds number, and the turbulence intensity (these last three associated with the location of injection) on single-particle and two-particle dispersion.
Download or read book Analysis of Stochastic Methods for Predicting Particle Dispersion in Turbulent Flows written by Kyle Paul Sala and published by . This book was released on 2013 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current research seeks to develop a computational model that accurately describes particle dispersion in turbulent flow. Current particle dispersion models do not accurately predict the small-scale clumping of particles in turbulent flow that occurs due to interaction with turbulent eddies. A new stochastic vortex structure (SVS) model was developed and compared with current stochastic Lagrangian models (SLM) for turbulent flows. To examine what characteristics of the fluid flow field that lead to dispersion of particles, a number of non trivial measures were used. A discrete-element model is used to transport particle locations for cases with and without adhesive forces. Direct numerical simulations (DNS) are used as a baseline for comparison between the two models. Initial results show that the SVS model matches the spatial structure of the flow field of DNS reasonably well, while the SLMs do not. Investigation of particle collision rate suggest that while SVS matches the large length scales of flow, it omits the smaller scales of the flow.
Download or read book Particle Dispersion and Inter phase Kinetic Energy Transfer in a Turbulent Two phase Shear Layer written by Kenneth T. Kiger and published by . This book was released on 1995 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transport of heavy, polydispersed particles and the inter-phase transfer of kinetic energy is measured experimentally in a turbulent shear layer. Specifically, fundamental/subharmonic forcing and conditional-averaging techniques were used to study the particle/turbulence interaction with the large-scale, spanwise, coherent vortices, starting from their initial roll-up through the first pairing event. It is shown that the pairing event plays a homogenizing role on the particulate field, but the amount of homogenization is strongly dependent upon the particle's viscous relaxation time, the eddy turnover time, as well as the time the particles are allowed to interact with each scale prior to a pairing event. Thus, even though the smaller size particles become well-mixed across the structure, the larger sizes are still dispersed in an inhomogeneous fashion. The dispersed/carrier phase coupling was examined through the measurement of conditionally-averaged kinetic energy transfer (which results from the work done to accelerate or decelerate the dispersed phase), as well as the conditionally-averaged particle dissipation (energy dissipated by shear deformation in the carrier phase due to the relative slip between the particles and the carrier fluid).
Download or read book Analysis of Deposition of Spherical and Ellipsoidal Particles in Turbulent Flows written by Fa-Gung Fan and published by . This book was released on 1994 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics of Gas Liquid Flows written by Thomas J. Hanratty and published by Cambridge University Press. This book was released on 2013-10-31 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting tools for understanding the behaviour of gas-liquid flows based on the ways large scale behaviour relates to small scale interactions, this text is ideal for engineers seeking to enhance the safety and efficiency of natural gas pipelines, water-cooled nuclear reactors, absorbers, distillation columns and gas lift pumps. The review of advanced concepts in fluid mechanics enables both graduate students and practising engineers to tackle the scientific literature and engage in advanced research. It focuses on gas-liquid flow in pipes as a simple system with meaningful experimental data. This unified theory develops design equations for predicting drop size, frictional pressure losses and slug frequency, which can be used to determine flow regimes, the effects of pipe diameter, liquid viscosity and gas density. It describes the effect of wavy boundaries and temporal oscillations on turbulent flows, and explains transition between phases, which is key to understanding the behaviour of gas-liquid flows.
Download or read book Direct and Large Eddy Simulation I written by Peter R. Voke and published by Springer Science & Business Media. This book was released on 1994-10-31 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is a truism that turbulence is an unsolved problem, whether in scientific, engin eering or geophysical terms. It is strange that this remains largely the case even though we now know how to solve directly, with the help of sufficiently large and powerful computers, accurate approximations to the equations that govern tur bulent flows. The problem lies not with our numerical approximations but with the size of the computational task and the complexity of the solutions we gen erate, which match the complexity of real turbulence precisely in so far as the computations mimic the real flows. The fact that we can now solve some turbu lence in this limited sense is nevertheless an enormous step towards the goal of full understanding. Direct and large-eddy simulations are these numerical solutions of turbulence. They reproduce with remarkable fidelity the statistical, structural and dynamical properties of physical turbulent and transitional flows, though since the simula tions are necessarily time-dependent and three-dimensional they demand the most advanced computer resources at our disposal. The numerical techniques vary from accurate spectral methods and high-order finite differences to simple finite-volume algorithms derived on the principle of embedding fundamental conservation prop erties in the numerical operations. Genuine direct simulations resolve all the fluid motions fully, and require the highest practical accuracy in their numerical and temporal discretisation. Such simulations have the virtue of great fidelity when carried out carefully, and repre sent a most powerful tool for investigating the processes of transition to turbulence.
