Download or read book TURBULENCE MODULATION UNDER LARGE PARTICLE LOADING written by Aidan Stephen Cronin and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle-laden turbulence is important to a diverse range of topics: from aerosol transport in the atmosphere to flocculation techniques treating our drinking water. Often the particles in flows of interest are large and non-spherical, making them difficult to study, and so simplified cases are considered to quantify turbulent behaviors. Experimental laboratory research has provided insight into the quantifiable behavior of these simplified particle-laden flows, notably in cases of homogeneous and isotropic (H.I) turbulence. For this research, we designed and constructed a novel laboratory turbulence tank for the study of particle-laden flows that could create a region of H.I turbulence at its center. To do so, we incorporated random, symmetric forcing on a completely new geometry (a modified icosahedron) intending to maintain the properties of H.I. turbulence while increasing the size of the region of the tank in which it is contained. This facility will provide a unique testbed for studies of particle-laden turbulence.
Download or read book Visualization of Turbulence Modulation with Large Particles written by Franz Demetrius Davis and published by . This book was released on 1993 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence Modulation in Gas particle Flows a Comparison of Selected Models written by Sarah M. Hodgson and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of turbulence modulation, the process whereby the gas-phase turbulence is modified by the presence of particles, is investigated. Experimental trends are examined and parameters affecting turbulence modulation and the mechanisms by which turbulence modulation occurs are identified. A new model that accounts for the crossing trajectory effect is presented. This model and the turbulence modulation models of Chen and Wood [4], Tu and Fletcher [45], and Mostafa and Mongia [30] are investigated using the TASCflow CFD code. The models are compared with the experimental results of Tsuji et al [44]. The model of Tu and Fletcher is not able to reproduce either general experimental trends or the experimental results, while the other three models can predict the general experimental trends but cannot reproduce the experimental results. Analysis shows that the turbulent viscosity, [mu]'t', plays an important role in modifying the turbulence intensity profiles. The new model was not able to capture the crossing trajectory effect for the flow considered.
Download or read book Turbulence Modulation in Particle Laden Flow with Mono Dispersed Droplets written by 呂偉福 and published by . This book was released on 2010 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence Generation in Homogeneous Dilute Particle laden Flows written by Jeng-Horng Chen and published by . This book was released on 1999 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence Modulation in Gas particle Flows a Comparison of Selected Models written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence Modulation in Particle laden Flows written by John D. Schwarzkopf and published by . This book was released on 2008 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Turbulence Modulation by Finite size Solid Particles with the Lattice Boltzmann Method written by Cheng Peng and published by . This book was released on 2018 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent flows laden with finite-size solid particles are found in a variety of natural and engineering processes. However, the overall understanding of how the flow properties, such as turbulent intensity and flow drag, are modified by the addition of the particles is still limited. So far, the only rigorous approach to investigate the modulation mechanisms at the particle scale is to numerically solve the disturbance flow around each particle, known as the interface-resolved simulations (IRS). However, the application of IRS in the turbulent particle-laden flow is particularly challenging due to the requirements of resolving all the length and time scales in the turbulent flow, as well as the need to realize the no-slip boundary condition on the moving particle surfaces. ☐ In recent years, the lattice Boltzmann method (LBM) has emerged as an efficient and accurate numerical approach for computational fluid dynamics. Compared to the conventional approaches of directly solving the Navier-Stokes equations, LBM is simple to code, easy to parallelize, and flexible in treating boundary conditions. In particular, the no-slip boundary treatment based on bounce-back scheme and mesoscopic momentum exchange in LBM take full advantage of the gas kinetic description. However, the realization of these treatments in particle-laden turbulent flow simulations is still rare. So far, the majority of the particle-laden turbulent flow simulations relies on the smoothed-boundary treatments, such as the immersed boundary methods, which tends to induce artificial dissipation. In this dissertation, LBM with a sharp-interface treatment is developed to investigate turbulence modulation by finite-size solid particles. ☐ After a thorough validation, the method is applied to the simulations of a turbulent channel flow laden with both fixed and moving particles. The interactions between the dispersed particles and carrier turbulent flows, especially the modulation induced by the particles on the turbulence intensity and its parameter dependence are examined. The addition of particles is found to result in a more homogeneous distribution of turbulent kinetic energy (TKE) in the wall normal direction and a more isotropic TKE distribution among different spatial directions, comparing to the single-phase turbulent channel flow. To gain further insight, the budget equations of both the total TKE and component-wise TKE in the particle-laden turbulent flows are derived and analyzed using the simulation data. The budget analysis of the total TKE shows that the production rate of TKE from the mean flow is modified to become more uniform in the wall-normal direction by the presence of particles, which is responsible for the more homogeneous distribution of TKE. Specifically, in the buffer region where the TKE source is maximized in the single-phase flow, the TKE source due to the mean shear is reduced since both the mean flow velocity gradient and the Reynolds stress are reduced by the presence of particles. This reduction is found to be related to the particle inertia, where particles with larger inertia result in greater reduction of the TKE source. On the other hand, particles pump energy to turbulent fluctuations by doing work directly (moving particles) or inducing disturbances to the mean flow (fixed particles), converting more mechanical energy from the mean flow to the turbulent motion. The strength of this extra TKE source is related to the dynamics of the wake developed behind particles and therefore is particle-Reynolds-number dependent. The relative strength of the above two mechanisms determines whether the turbulence intensity of a turbulent channel flow is augmented or attenuated by the presence of particles. The budget analysis of component-wise TKE reveals that the more isotropic distribution of TKE among different spatial directions results from the enhanced inter-components transfer of TKE. This enhancement is found to originate from the spherical shape of the particles and particle rotation. ☐ In summary, the improved LBM simulation method based on the sharp-interface treatment provides a better alternative for particle-laden turbulent flow simulations than the commonly used smoothed-interface treatments. The physical results from this dissertation research advance our understanding of flow modulation induced by finite-size solid particles in turbulent flows, particularly in wall-bounded turbulent flows.
Download or read book Turbulence Modulation of Carrier phase in Fluid particle Flows written by Pengfei Wang and published by . This book was released on 2000 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Particle and Granular Flow Systems written by Nan Gui and published by Elsevier. This book was released on 2019-11-06 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas-Particle and Granular Flow Systems: Coupled Numerical Methods and Applications breaks down complexities, details numerical methods (including basic theory, modeling and techniques in programming), and provides researchers with an introduction and starting point to each of the disciplines involved. As the modeling of gas-particle and granular flow systems is an emerging interdisciplinary field of study involving mathematics, numerical methods, computational science, and mechanical, chemical and nuclear engineering, this book provides an ideal resource for new researchers who are often intimidated by the complexities of fluid-particle, particle-particle, and particle-wall interactions in many disciplines. Presents the most recent advances in modeling of gas-particle and granular flow systems Features detailed and multidisciplinary case studies at the conclusion of each chapter to underscore key concepts Discusses coupled methods of particle and granular flow systems theory and includes advanced modeling tools and numerical techniques
Download or read book Turbulence Modification in Multiphase Flows written by and published by . This book was released on 1991 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Turbulence Modulation in Fluid Particle Systems written by C. T. Crowe and published by . This book was released on 1998 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two Phase Flow written by Cl Kleinstreuer and published by Routledge. This book was released on 2017-11-01 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: This graduate text provides a unified treatment of the fundamental principles of two-phase flow and shows how to apply the principles to a variety of homogeneous mixture as well as separated liquid-liquid, gas-solid, liquid-solid, and gas-liquid flow problems, which may be steady or transient, laminar or turbulent.Each chapter contains several sample problems, which illustrate the outlined theory and provide approaches to find simplified analytic descriptions of complex two-phase flow phenomena.This well-balanced introductory text will be suitable for advanced seniors and graduate students in mechanical, chemical, biomedical, nuclear, environmental and aerospace engineering, as well as in applied mathematics and the physical sciences. It will be a valuable reference for practicing engineers and scientists. A solutions manual is available to qualified instructors.
Download or read book Fluid Dynamics of Particles Drops and Bubbles written by and published by Cambridge University Press. This book was released on with total page 573 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Turbulent and Multiphase Combustion written by Kenneth Kuan-yun Kuo and published by John Wiley & Sons. This book was released on 2012-07-03 with total page 914 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed coverage of advanced combustion topics from the author of Principles of combustion, Second Edition Turbulence, turbulent combustion, and multiphase reacting flows have become major research topics in recent decades due to their application across diverse fields, including energy, environment, propulsion, transportation, industrial safety, and nanotechnology. Most of the knowledge accumulated from this research has never been published in book form—until now. Fundamentals of Turbulent and Multiphase Combustion presents up-to-date, integrated coverage of the fundamentals of turbulence, combustion, and multiphase phenomena along with useful experimental techniques, including non-intrusive, laser-based measurement techniques, providing a firm background in both contemporary and classical approaches. Beginning with two full chapters on laminar premixed and non-premixed flames, this book takes a multiphase approach, beginning with more common topics and moving on to higher-level applications. In addition, Fundamentals of Turbulent and Multiphase Combustion: Addresses seven basic topical areas in combustion and multiphase flows, including laminar premixed and non-premixed flames, theory of turbulence, turbulent premixed and non-premixed flames, and multiphase flows Covers spray atomization and combustion, solid-propellant combustion, homogeneous propellants, nitramines, reacting boundary-layer flows, single energetic particle combustion, and granular bed combustion Provides experimental setups and results whenever appropriate Supported with a large number of examples and problems as well as a solutions manual, Fundamentals of Turbulent and Multiphase Combustion is an important resource for professional engineers and researchers as well as graduate students in mechanical, chemical, and aerospace engineering.
Download or read book Numerical Study of Turbulence Modulation in Gas particulate Flows written by Abhishek Shrivastava and published by . This book was released on 2006 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluid Dynamics of Particles Drops and Bubbles written by Eric Loth and published by Cambridge University Press. This book was released on 2023-06-30 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: A modern presentation of multiphase flow, from basic principles to state-of-the-art research. Explains dispersed fluid dynamics for bubbles, drops, or solid particles, incorporating detailed theory, experiments, simulations, and models while considering applications and recent cutting-edge advances. The book demonstrates the importance of multiphase flow in engineering and natural systems, considering particle size distributions, shapes and trajectories as well as deformation of fluid particles and multiphase flow numerical methods. The scope of the book also includes coupling physics between particles and turbulence through dispersion and modulation, and specific phenomena such as gravitational settling and collisions for solid particles, drops and bubbles. Featuring over eighty homework problems for each of the primary chapters, including theory-based and engineering application questions. The comprehensive coverage will give the reader a solid grounding for multiphase flow research and design, applicable to current and future engineering. This is an ideal resource for graduate students, researchers and professionals.
