Download or read book Numerical Experiments on Forced Isotropic Homogeneous Turbulence written by Neal Patrick Sullivan and published by . This book was released on 1992 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Experiments in Homogeneous Turbulence written by Robert Sugden Rogallo and published by . This book was released on 1981 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Experiments on Turbulent Mixing written by Stephen B. Pope and published by . This book was released on 1988 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixing in simple turbulent flows has been investigating using 64 cubed and 128 cubed Direct Numerical Simulations. In turbulent combustion, mixing by molecular transport is an essential process that is not well understood. Because mixing occurs on the smallest length and time scales it is difficult to study experimentally. Instead, we have employed direct numerical simulation of turbulence, initially for a conserved passive scalar in homogeneous isotropic turbulence. The Eulerian velocity and scalar fields are calculated from the exact evolution equations, and both Eulerian and Lagrangian statistics are deduced from the computed fields. A particle-tracking scheme, needed to extract Lagrangian information, has been implemented. The testing of a number of such particle tracking schemes has been completed with good results: accurate Lagrangian information can be extracted at a modest computational cost. In order to study processes in stationary turbulence, a forcing algorithm has been implemented. Tests on this scheme are complete, again with good results: the small scales are unaffected by the details of the forcing. Studies have been performed of: the mixing of a passive scalar; Lagrangian velocity, Acceleration and dissipation statistics; and Mixing and combustion problems viewed in terms of surfaces.
Download or read book Homogeneous Turbulence Dynamics written by Pierre Sagaut and published by Springer. This book was released on 2018-03-23 with total page 912 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides state-of-the-art results and theories in homogeneous turbulence, including anisotropy and compressibility effects with extension to quantum turbulence, magneto-hydodynamic turbulence and turbulence in non-newtonian fluids. Each chapter is devoted to a given type of interaction (strain, rotation, shear, etc.), and presents and compares experimental data, numerical results, analysis of the Reynolds stress budget equations and advanced multipoint spectral theories. The role of both linear and non-linear mechanisms is emphasized. The link between the statistical properties and the dynamics of coherent structures is also addressed. Despite its restriction to homogeneous turbulence, the book is of interest to all people working in turbulence, since the basic physical mechanisms which are present in all turbulent flows are explained. The reader will find a unified presentation of the results and a clear presentation of existing controversies. Special attention is given to bridge the results obtained in different research communities. Mathematical tools and advanced physical models are detailed in dedicated chapters.
Download or read book Numerical Experiments on the Structure of Homogeneous Turbulence written by Moon Joo Lee and published by . This book was released on 1986 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Theory of Homogeneous Turbulence written by G. K. Batchelor and published by Cambridge University Press. This book was released on 1953 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a reissue of Professor Batchelor's text on the theory of turbulent motion, which was first published by Cambridge Unviersity Press in 1953. It continues to be widely referred to in the professional literature of fluid mechanics, but has not been available for several years. This classic account includes an introduction to the study of homogeneous turbulence, including its mathematic representation and kinematics. Linear problems, such as the randomly-perturbed harmonic oscillator and turbulent flow through a wire gauze, are then treated. The author also presents the general dynamics of decay, universal equilibrium theory, and the decay of energy-containing eddies. There is a renewed interest in turbulent motion, which finds applications in atmospheric physics, fluid mechanics, astrophysics, and planetary science.
Download or read book Homogeneous Isotropic Turbulence written by W. David McComb and published by OUP Oxford. This book was released on 2014-02-27 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluid turbulence is often referred to as `the unsolved problem of classical physics'. Yet, paradoxically, its mathematical description resembles quantum field theory. The present book addresses the idealised problem posed by homogeneous, isotropic turbulence, in order to concentrate on the fundamental aspects of the general problem. It is written from the perspective of a theoretical physicist, but is designed to be accessible to all researchers in turbulence, both theoretical and experimental, and from all disciplines. The book is in three parts, and begins with a very simple overview of the basic statistical closure problem, along with a summary of current theoretical approaches. This is followed by a precise formulation of the statistical problem, along with a complete set of mathematical tools (as needed in the rest of the book), and a summary of the generally accepted phenomenology of the subject. Part 2 deals with current issues in phenomenology, including the role of Galilean invariance, the physics of energy transfer, and the fundamental problems inherent in numerical simulation. Part 3 deals with renormalization methods, with an emphasis on the taxonomy of the subject, rather than on lengthy mathematical derivations. The book concludes with some discussion of current lines of research and is supplemented by three appendices containing detailed mathematical treatments of the effect of isotropy on correlations, the properties of Gaussian distributions, and the evaluation of coefficients in statistical theories.
Download or read book Problem Description for a Numerical Simulation of Forced Homogeneous Isotropic Turbulence written by M. N. Kooper and published by . This book was released on 1995 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies in Turbulence written by Thomas B. Gatski and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 609 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Numerical Simulations of the Lagrangian averaged Navier Stokes Equations for Forced Homogeneous Isotropic Turbulence written by Kamran Mohseni and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Flows written by G. Biswas and published by Narosa Publishing House. This book was released on 2002 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book allows readers to tackle the challenges of turbulent flow problems with confidence. It covers the fundamentals of turbulence, various modeling approaches, and experimental studies. The fundamentals section includes isotropic turbulence and anistropic turbulence, turbulent flow dynamics, free shear layers, turbulent boundary layers and plumes. The modeling section focuses on topics such as eddy viscosity models, standard K-E Models, Direct Numerical Stimulation, Large Eddy Simulation, and their applications. The measurement of turbulent fluctuations experiments in isothermal and stratified turbulent flows are explored in the experimental methods section. Special topics include modeling of near wall turbulent flows, compressible turbulent flows, and more.
Download or read book Numerical Forcing of Horizontally homogeneous Stratified Turbulence written by Kaustubh Rao and published by . This book was released on 2011 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is often desirable to study simulated turbulent flows at steady state even if the flow has no inherent source of turbulence kinetic energy. Doing so requires a numerical forcing scheme and various methods have been studied extensively for turbulence that is isotropic and homogeneous in three dimensions. A review of these existing schemes is used to form a framework for more general forcing methods. In this framework, the problem of developing a forcing scheme in Fourier space is abstracted into the two problems of (1) prescribing the spectrum of the input power and (2) specifying a force that has the desired characteristics and that adds energy to the flow with the correct spectrum. The framework is used to construct three forcing schemes for horizontally homogeneous and isotropic, vertically stratified turbulence. These schemes are implemented in large-eddy simulations and their characteristics analyzed. Which method is "best" depends on the purpose of the simulations, but the framework for specifying forcing schemes enables a systematic approach for identifying a method appropriate for a particular application.
Download or read book Parametric Study of Decay of Homogeneous Isotropic Turbulence Using Large Eddy Simulation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-22 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical simulations of decaying homogeneous isotropic turbulence are performed with both low-order and high-order spatial discretization schemes. The turbulent Mach and Reynolds numbers for the simulations are 0.2 and 250, respectively. For the low-order schemes we use either second-order central or third-order upwind biased differencing. For higher order approximations we apply weighted essentially non-oscillatory (WENO) schemes, both with linear and nonlinear weights. There are two objectives in this preliminary effort to investigate possible schemes for large eddy simulation (LES). One is to explore the capability of a widely used low-order computational fluid dynamics (CFD) code to perform LES computations. The other is to determine the effect of higher order accuracy (fifth, seventh, and ninth order) achieved with high-order upwind biased WENO-based schemes. Turbulence statistics, such as kinetic energy, dissipation, and skewness, along with the energy spectra from simulations of the decaying turbulence problem are used to assess and compare the various numerical schemes. In addition, results from the best performing schemes are compared with those from a spectral scheme. The effects of grid density, ranging from 32 cubed to 192 cubed, on the computations are also examined. The fifth-order WENO-based scheme is found to be too dissipative, especially on the coarser grids. However, with the seventh-order and ninth-order WENO-based schemes we observe a significant improvement in accuracy relative to the lower order LES schemes, as revealed by the computed peak in the energy dissipation and by the energy spectrum. Swanson, R. C. and Rumsey, Christopher L. and Rubinstein, Robert and Balakumar, Ponnampalam and Zang, Thomas A. Langley Research Center COMPUTATIONAL FLUID DYNAMICS; HOMOGENEOUS TURBULENCE; ISOTROPIC TURBULENCE; LARGE EDDY SIMULATION; PARAMETERIZATION; DIRECT NUMERICAL SIMULATION; ESSENTIALLY NON-OSCILLATORY SCHEMES; ENERGY SPECTRA; NONLINEARITY; MACH N
Download or read book Direct Numerical Investigations of Dilute Dispersed Flows in Homogeneous Turbulence written by Aditya U. Karnik and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The motivation for the present work is to investigate particle-laden turbulent flows using accurate numerical simulations. In the present work, the carrier phase is modeled using direct numerical simulations (DNS) and the particles are tracked in a Lagrangian sense. Investigations of both one-way and two-way coupled particulate flows in homogeneous isotropic turbulence have been carried out. The phenomenon of interest in one-way coupled simulations is preferential accumulation, which refers to the tendency of heavy particles in isotropic turbulence to collect in regions of high strain and low vorticity. Several measures and mechanisms of accumulation have been reported in the literature often showing conflicting scaling with particle and fluid parameters. In the present study, accumulation has been quantified using several indicators to give a unified picture. The present work addresses the scaling of preferential accumulation with Reynolds number and suggests that while the spacing between particle clusters does exhibit a dependence on Reynolds number, the structure of particle clusters as viewed by individual particles shows little dependence on Reynolds number. The effect of adding a gravitational settling force on the particles has also been explored. While the gravity force tends to homogenize the particle distribution at low Stokes numbers, at high Stokes numbers it tends to arrange the originally random distribution into streaks in the direction of gravity. The ability of the Lorentz force to limit preferential accumulation has been the focus of the next part of the study. Charges are placed on particles to produce an electric field when the particles are inhomogeneously distributed. The electric field and thereby the Lorentz force tend to homogenize the particle distribution. It is interesting to note that the particle distribution attains a stationary state determined by the total amount of charge contained in the domain. It is demonstrated that in the presence of gravity, less amount of charge is required to homogenise particle distribution. Good agreement is observed for simulations of settling charged particles with experimental work. The modification of carrier phase turbulence by particles is studied formono-sized particles. The non-uniform modification of the fluid energy spectrum by particles has been demonstrated. It is seen that there is an increase in energy at high wave numbers for microparticles (St k
Download or read book Turbulence and Particle Dynamics in Dense Crystal Slurries written by Andreas ten Cate and published by Delft University Press. This book was released on 2002 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents of this Doctoral Dissertation include: The microscopic modelling of hydrodynamics in industrial crystallizers, PIV experiments and lattice-Boltzmann simulations on a single sphere settling under gravity, Application of spectral forcing in lattice-Boltzmann simulations of homogeneous turbulence, Fully resolved simulations of colliding monodisperse spheres in forced isotropic turbulence, An assessment of fragmentation due to crystal-crystal collisions, Conclusions and Perspectives
Download or read book New Approaches and Concepts in Turbulence written by T. Dracos and published by Springer Science & Business Media. This book was released on 1993-09-01 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the proceedings of a colloquium held in Monte Verità from September 9-13, 1991. Special care has been taken to devote adequate space to the scientific discussions, which claimed about half of the time available. Scientists from all over the world presented their views on the importance of kinematic properties, topology and fractal geometry, and on the dynamic behaviour of turbulent flows. They debated the importance of coherent structures and the possibility to incorporate these in the statistical theory of turbulence, as well as their significance for the reduction of the degrees of freedom and the prospective of dynamical systems and chaos approaches to the problem of turbulence. Also under discussion was the relevance of these new approaches to the study of the instability and the origin of turbulence, and the importance of numerical and physical experiments in improving the understanding of turbulence.
Download or read book Numerical Simulation of Turbulence in the Presence of Shear written by Shlomo Shaanan and published by . This book was released on 1975 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
