The dynamics of finite-size settling particles

The dynamics of finite-size settling particles
Author: Doychev, Todor
Publisher: KIT Scientific Publishing
Total Pages: 272
Release: 2015-01-27
Genre: Engineering (General). Civil engineering (General)
ISBN: 3731503077

This book contributes to the fundamental understanding of the physical mechanisms that take place in pseudo turbulent particulate flows. In the present work we have considered the sedimentation of large numbers of spherical rigid particles in an initially quiescent flow field. We have performed direct numerical simulations employing an immersed boundary method for the representation of the fluid-solid interface. The results evidence that depending on the particle settling regime (i.e. Galileo number and particle-to-fluid density ratio) the particles may exhibit strong inhomogeneous spatial distribution. It is found that the particles are preferentially located in regions with downward fluid motion. The particles inside clusters experience larger settling velocities than the average. The flow in all flow cases is observed to exhibit characteristic features of pseudo-turbulence. The particle-induced flow field is further found to be highly anisotropic with dominant vertical components. The results indicate that, in the present flow configurations, the collective and mobility effects play significant role for the particle and fluid motion.

Particles in Turbulent Flows

Particles in Turbulent Flows
Author: Leonid I. Zaichik
Publisher: John Wiley & Sons
Total Pages: 318
Release: 2008-12-04
Genre: Science
ISBN: 3527626263

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.

Modeling Approaches and Computational Methods for Particle-laden Turbulent Flows

Modeling Approaches and Computational Methods for Particle-laden Turbulent Flows
Author: Shankar Subramaniam
Publisher: Academic Press
Total Pages: 588
Release: 2022-10-20
Genre: Technology & Engineering
ISBN: 0323901344

Modelling Approaches and Computational Methods for Particle-laden Turbulent Flows introduces the principal phenomena observed in applications where turbulence in particle-laden flow is encountered while also analyzing the main methods for analyzing numerically. The book takes a practical approach, providing advice on how to select and apply the correct model or tool by drawing on the latest research. Sections provide scales of particle-laden turbulence and the principal analytical frameworks and computational approaches used to simulate particles in turbulent flow. Each chapter opens with a section on fundamental concepts and theory before describing the applications of the modelling approach or numerical method. Featuring explanations of key concepts, definitions, and fundamental physics and equations, as well as recent research advances and detailed simulation methods, this book is the ideal starting point for students new to this subject, as well as an essential reference for experienced researchers. - Provides a comprehensive introduction to the phenomena of particle laden turbulent flow - Explains a wide range of numerical methods, including Eulerian-Eulerian, Eulerian-Lagrange, and volume-filtered computation - Describes a wide range of innovative applications of these models

Dynamics of Non-Spherical Particles in Turbulence

Dynamics of Non-Spherical Particles in Turbulence
Author: Luis Blay Esteban
Publisher: Springer
Total Pages: 180
Release: 2019-08-13
Genre: Technology & Engineering
ISBN: 3030281361

This book studies the dynamics of 2D objects moving through turbulent fluids. It examines the decay of turbulence over extended time scales, and compares the dynamics of non-spherical particles moving through still and turbulent fluids. The book begins with an introduction to the project, its aims, and its relevance for industrial applications. It then discusses the movement of planar particles in quiescent fluid, and presents the numerous methodologies used to measure it. The book also presents a detailed analysis of the falling style of irregular particles, which makes it possible to estimate particle trajectory and wake morphology based on frontal geometry. In turn, the book provides the results of an analysis of physically constrained decaying turbulence in a laboratory setting. These results suggest that large-scale cut-off in numerical simulations can result in severe bias in the computed turbulent kinetic energy for long waiting times. Combining the main text with a wealth of figures and sketches throughout, the book offers an accessible guide for all engineering students with a basic grasp of fluid mechanics, while the key findings will also be of interest to senior researchers.

Nonlinear Dynamics and Chaos: Advances and Perspectives

Nonlinear Dynamics and Chaos: Advances and Perspectives
Author: Marco Thiel
Publisher: Springer
Total Pages: 300
Release: 2010-05-17
Genre: Science
ISBN: 3642046290

This book is a collection of papers contributed by some of the greatest names in the areas of chaos and nonlinear dynamics. Each paper examines a research topic at the frontier of the area of dynamical systems. As well as reviewing recent results, each paper also discusses the future perspectives of each topic. The result is an invaluable snapshot of the state of the ?eld by some of the most important researchers in the area. The ?rst contribution in this book (the section entitled “How did you get into Chaos?”) is actually not a paper, but a collection of personal accounts by a number of participants of the conference held in Aberdeen in September 2007 to honour Celso Grebogi’s 60th birthday. At the instigation of James Yorke, many of the most well-known scientists in the area agreed to share their tales on how they got involved in chaos during a celebratory dinner in Celso’s honour during the conference. This was recorded in video, we felt that these accounts were a valuable historic document for the ?eld. So we decided to transcribe it and include it here as the ?rst section of the book.

A hydrodynamical perspective on the turbulent transport of bacteria in rivers

A hydrodynamical perspective on the turbulent transport of bacteria in rivers
Author: Krayer, Michael Werner Tobias
Publisher: KIT Scientific Publishing
Total Pages: 290
Release: 2023-09-11
Genre:
ISBN: 3731513102

The transport of bacteria in turbulent river-like environments is addressed, where bacterial populations are frequently encountered attached to solids. This transport mode is investigated by studying the transient settling of heavy particles in turbulent channel flows featuring sediment beds. A numerical method is used to fully resolve turbulence and finite-size particles, which enables the assessment of the complex interplay between flow structures, suspended solids and river sediment.

The formation of patterns in subaqueous sediment

The formation of patterns in subaqueous sediment
Author: Kidanemariam, Aman Ghebremichael
Publisher: KIT Scientific Publishing
Total Pages: 180
Release: 2016-11-14
Genre: Engineering (General). Civil engineering (General)
ISBN: 3731505320

This book investigates the formation of subaqueous patterns by means of high-fidelity numerical simulations which resolve all the relevant scales of the flow and the sediment bed. This is required to provide a space- and time-resolved information on the flow field and the sediment bed. Secondly, detailed analysis of the generated data allows to address the different governing mechanisms involved in the formation of patterns as well as to access the validity of various existing models.

Turbulent coherent structures, Secondary currents and Sediment ridges

Turbulent coherent structures, Secondary currents and Sediment ridges
Author: Scherer, Markus Maximilian
Publisher: KIT Scientific Publishing
Total Pages: 348
Release: 2024-06-19
Genre:
ISBN: 3731513188

The origin of secondary currents and subaqueous sediment patterns in natural rivers is analysed from first principles. For this purpose, simulations of sediment transport in canonical turbulent open channel flows are performed using a numerical technique that resolves all relevant flow scales and the dynamics of the individual sand grains. The high-fidelity datasets reveal the fundamental importance of individual coherent structures for the development of sediment patterns and secondary flows.