Author : Quoc Tan Nguyen
Publisher :
Page : 256 pages
File Size : 30,10 MB
Release : 2016
Category : Fluid dynamics
ISBN :
Author : Prakash Vedula
Publisher :
Page : 284 pages
File Size : 36,55 MB
Release : 2001
Category : Turbulence
ISBN :
Author : William Layton
Publisher : MDPI
Page : 229 pages
File Size : 34,4 MB
Release : 2018-05-04
Category : Mathematics
ISBN : 3038428094
This book is a printed edition of the Special Issue "Turbulence: Numerical Analysis, Modelling and Simulation" that was published in Fluids
Author : Juan Ignacio Polanco
Publisher :
Page : 0 pages
File Size : 14,33 MB
Release : 2019
Category :
ISBN :
The Lagrangian perspective, describing a flow from the trajectories of fluid tracers, isa natural framework for studying dispersion phenomena in turbulent flows. In wall-boundedturbulence, the motion of fluid tracers is affected by mean shear and by strong inhomogeneityand anisotropy near walls. We investigate the Lagrangian properties of a turbulent channel flowusing direct numerical simulations at a moderate Reynolds number. Lagrangian accelerationstatistics are compared to particle tracking experiments performed in parallel to this work. Asin homogeneous isotropic turbulence (HIT), the acceleration components along Lagrangianpaths decorrelate over time scales representative of the smallest scales of the flow, while theacceleration norm stays correlated for much longer. The persistence of small-scale anisotropy farfrom the wall is demonstrated in the form of a non-zero cross-correlation between accelerationcomponents. As a result of the average fluxes of kinetic energy in wall turbulence, tracers initiallylocated close to the wall travel and spread over longer distances when tracked backwardsin time than forwards. The relative dispersion of tracer pairs is finally investigated. At shorttimes, pair separation is ballistic for all wall distances. As in HIT, relative dispersion is timeasymmetric, with tracers separating faster when tracked backwards in time. At longer times,mean shear dominates leading to rapid separation in the mean flow direction. A ballisticcascade model previously proposed for HIT is adapted to inhomogeneous flows.
Author : Larry A. Glasgow
Publisher : John Wiley & Sons
Page : 519 pages
File Size : 25,50 MB
Release : 2010-12-01
Category : Technology & Engineering
ISBN : 1118031776
Enables readers to apply transport phenomena principles to solve advanced problems in all areas of engineering and science This book helps readers elevate their understanding of, and their ability to apply, transport phenomena by introducing a broad range of advanced topics as well as analytical and numerical solution techniques. Readers gain the ability to solve complex problems generally not addressed in undergraduate-level courses, including nonlinear, multidimensional transport, and transient molecular and convective transport scenarios. Avoiding rote memorization, the author emphasizes a dual approach to learning in which physical understanding and problem-solving capability are developed simultaneously. Moreover, the author builds both readers' interest and knowledge by: Demonstrating that transport phenomena are pervasive, affecting every aspect of life Offering historical perspectives to enhance readers' understanding of current theory and methods Providing numerous examples drawn from a broad range of fields in the physical and life sciences and engineering Contextualizing problems in scenarios so that their rationale and significance are clear This text generally avoids the use of commercial software for problem solutions, helping readers cultivate a deeper understanding of how solutions are developed. References throughout the text promote further study and encourage the student to contemplate additional topics in transport phenomena. Transport Phenomena is written for advanced undergraduates and graduate students in chemical and mechanical engineering. Upon mastering the principles and techniques presented in this text, all readers will be better able to critically evaluate a broad range of physical phenomena, processes, and systems across many disciplines.
Author : Shankar Subramaniam
Publisher : Academic Press
Page : 588 pages
File Size : 46,45 MB
Release : 2022-10-20
Category : Science
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
Author : Thomas B. Gatski
Publisher : Springer Science & Business Media
Page : 609 pages
File Size : 42,52 MB
Release : 2012-12-06
Category : Science
ISBN : 1461227925
This book contains contributions by former students, colleagues and friends of Professor John L. Lumley, on the occasion of his 60th birthday, in recognition of his enormous impact on the advancement of turbulence research. A variety of experimental, computational and theoretical topics, including turbulence modeling, direct numerical simulations, compressible turbulence, turbulent shear flows, coherent structures and the Proper Orthogonal Decomposition are contained herein. The diversity and scope of these contributions are further acknowledgment of John Lumley's wide ranging influence in the field of turbulence. The large number of contributions by the authors, many of whom were participants in The Lumley Symposium: Recent Developments in Turbulence (held at ICASE, NASA Langley Research Center on November 12 & 13, 1990), has presented us with the unique opportu nity to select a few numerical and theoretical papers for inclusion in the journal Theoretical and Computational Fluid Dynamics for which Professor Lumley serves as Editor. Extended Abstracts of these pa pers are included in this volume and are appropriately marked. The special issue of TCFD will appear this year and will serve as an additional tribute to John Lumley. As is usually the case, the efforts of others have significantly eased our tasks. We would like to express our deep appreciation to Drs. R.
Author : Center for Turbulence Research (U.S.)
Publisher :
Page : 366 pages
File Size : 47,25 MB
Release : 1990
Category : Turbulence
ISBN :
Author : Bernhard Vowinckel
Publisher : Tudpress Verlag Der Wissenschaften Gmbh
Page : 160 pages
File Size : 48,14 MB
Release : 2015-03-27
Category :
ISBN : 9783959080026
Phase-resolving Direct Numerical Simulations of bed-load transport in a horizontal turbulent open-channel flow at small relative submergence are presented. The thesis provides a detailed study addressing the impact of the choice of collision model on the scenario of bed-load transport and presents statistical tools to identify and describe the key-mechanisms governing the fluid-particle interaction. The Double-Averaging Methodology is applied for the first time to the situation of mobile rough beds. This methodology provides a framework to convolute the data in such a way that the most prominent flow features are well described by a handy set of double-averaged (in time and space) quantities. The thesis further provides a systematic study elucidating in detail the impact of the key-parameters mobility and sediment supply on the pattern formation of large-scale particle clusters. This is done using a very large computational domain to allow bed-forms to evolve with minimal spatial constraints. It is found that a low transport rate is linked to streamwise oriented ridges, while a large sediment supply results in large-scale clusters that propagate in streamwise direction. A detailed description of fluid quantities links the developed particle patterns to the enhancement of turbulence. The large domain allows for a large number of independent erosion events, such that conditional averaging provides a very clear description of the processes involved for incipient particle motion. Furthermore, the detection of moving particle clusters as well as the investigation of their surrounding flow field is performed by an analysis using a moving frame coordinate system.
Author : Abdallah Sofiane Berrouk
Publisher : Bentham Science Publishers
Page : 130 pages
File Size : 43,13 MB
Release : 2011
Category : Science
ISBN : 1608052966
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.
