Turbulence Structures Associated with the Bursting Event PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Turbulence Structures Associated with the Bursting Event PDF full book. Access full book title Turbulence Structures Associated with the Bursting Event by . Download full books in PDF and EPUB format.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 34
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 34
Get Book Here
Book Description
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781724754837
Category :
Languages : en
Pages : 30
Get Book Here
Book Description
Turbulence structures in a wall bounded shear layer during the bursting event detected by a conditional sampling technique are investigated using data obtained from large eddy simulation of turbulent channel flow. Streamlines are constructed from the ensemble-averaged velocity field to illustrate the flow patterns associated with the bursting event. The spatting motions during the sweep event and the existence of a pair of counterrotating streamwise vortices during the ejection process are exhibited. Kim, J. Ames Research Center NASA-TM-85944, A-9692, NAS 1.15:85944 RTOP 505-31-01-01
Author: Ronald Lee Panton
Publisher: Computational Mechanics
ISBN:
Category : Science
Languages : en
Pages : 448
Get Book Here
Book Description
Why is wall turbulence self-sustaining? In this book well-regarded researchers not only discuss what they know and believe, but also speculate on ideas that still require numerical or experimental testing and verification. An initial brief history of boundary layer structure research is followed by chapters on experimental information and specific topics within the subject. There are then sections on computational aspects.
Author: H.W. Liepmann
Publisher: Springer Science & Business Media
ISBN: 3642832814
Category : Science
Languages : en
Pages : 530
Get Book Here
Book Description
The last two decades have witnessed an intensifying effort in learning how to manage flow turbulence: it has in fact now become one of the most challenging and prized techno logical goals in fluid dynamics. The goal itself is of course not new. More than a hundred years ago, Reynolds already listed factors conducive to laminar and to turbulent flow (including among them curvature and acceleration). Further more, it is in retrospect clear that there were several early instances ot successful turbulence management. Examples are the reduction in drag achieved with a ring-trip placed on the front of a sphere or the insertion of a splitter-plate behind a circular cylinder; by the early 1950s there were numerous exercises at boundary layer control. Although many of these studies were interesting and suggestive, they led . to no spectacularly successful practical application, and the effort petered out in the late 1950s. The revival of interest in these problems in recent years can be attributed to the emergence of several new factors. First of all, fresh scientific insight into the structure of turbulence, in particular the accumulated evidence for the presence of significant order in turbulent flow, has been seen to point to new methods of managing turbulence. A second major reason has been the growing realisation that the rate at which the world is consuming its reserves of fossil fuels is no longer negligible; the economic value of greater energy effi ciency and lower drag has gone up significantly.
Author: O. Métais
Publisher: Springer Science & Business Media
ISBN: 9401579040
Category : Technology & Engineering
Languages : en
Pages : 612
Get Book Here
Book Description
In the last 25 years, one of the most striking advances in Fluid Mecha nics was certainly the discovery of coherent structures in turbulence: lab oratory experiments and numerical simulations have shown that most turbulent flows exhibit both spatially-organized large-scale structures and disorganized motions, generally at smaller scales. The develop ment of new measurement and visualization techniques have allowed a more precise characterization and investigation of these structures in the laboratory. Thanks to the unprecedented increase of computer power and to the development of efficient interactive three-dimensional colour graphics, computational fluid dynamicists can explore the still myste rious world of turbulence. However, many problems remain unsolved concerning the origin of these structures, their dynamics, and their in teraction with the disorganized motions. In this book will be found the latest results of experimentalists, theoreticians and numerical modellers interested in these topics. These coherent structures may appear on airplane wings or slender bodies, mixing layers, jets, wakes or boundary-layers. In free-shear flows and in boundary layers, the results presented here highlight the intense three-dimensional character of the vortices. The two-dimensional large scale eddies are very sensitive to three-dimensional perturbations, whose amplification leads to the formation of three-dimensional coherent vorti cal structures, such as streamwise, hairpin or horseshoe vortex filaments. This book focuses on modern aspects of turbulence study. Relations between turbulence theory and optimal control theory in mathematics are discussed. This may have important applications with regard to, e. g. , numerical weather forecasting.
Author: Albert Gyr
Publisher: Springer Science & Business Media
ISBN: 3642509711
Category : Science
Languages : en
Pages : 617
Get Book Here
Book Description
In 1976 a similar titled IUTAM Symposium (Structure of Turbulence and Drag Reduction) was held in Washington . However, the progress made during the last thirteen years as weil as the much promising current research desired a second one this year. In Washington drag reduction by additives and by direct manipulation of the walls (compliant walls and heated surfaces) were discussed. In the meantime it became evident that drag reduction also occurs when turbulence is influenced by geometrical means, e.g. by influencing the pressure distribution by the shape of the body (airfoils) or by the introduction of streamwise perturbances on a body (riblets). In the recent years turbulence research has seen increasing attention being focused on the investigation of coherent structures, mainly in Newtonian fluids. We all know that these structures are a significant feature of turbulent flows, playing an important role in the energy balance in such flows. However their place in turbulence theories as weil as the factors influencing their development are still poorly understood. Consequently, the investigation of phenomena in which the properties of coherent structures are alte red provides a promising means of improving our understanding of turbulent flows in general.
Author: Hiroji Nakagawa
Publisher: Routledge
ISBN: 1351406604
Category : Technology & Engineering
Languages : en
Pages : 246
Get Book Here
Book Description
A review of open channel turbulence, focusing especially on certain features stemming from the presence of the free surface and the bed of a river. Part one presents the statistical theory of turbulence; Part two addresses the coherent structures in open-channel flows and boundary layers.
Author: Baochun Fan
Publisher: John Wiley & Sons
ISBN: 1118718011
Category : Science
Languages : en
Pages : 397
Get Book Here
Book Description
This book introduces the mathematical techniques for turbulence control in a form suitable for inclusion in an engineering degree program at both undergraduate and postgraduate levels whilst also making it useful to researchers and industrial users of the concepts. It uses a mix of theory, computation and experimental results to present and illustrate the methodologies. It is based on the three part structure, wall turbulence, open loop control and feedback control with emphasis on optimal control methodologies. The book also includes an introduction of basic principles and fundamentals followed by a chapter on the structure of wall turbulence with emphasis on coherent structures. Elsewhere there is focus on control methods of wall turbulence by manipulating the boundaries though their motion and by applying control forces throughout the flow volume. The last two chapters will describe the linear and non-linear optimal controls. This integrated approach will help not only researchers interested in the topic but also graduate or advanced undergraduate students in their course work.
Author: M. I. Camacho
Publisher:
ISBN:
Category : Mathematics
Languages : en
Pages : 446
Get Book Here
Book Description
Author: Thomas B. Gatski
Publisher: Springer Science & Business Media
ISBN: 1461227925
Category : Science
Languages : en
Pages : 609
Get Book Here
Book Description
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.
