Download or read book Turbulent Shear Flows 5 written by Franz Durst and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first four symposia in the series on turbulent shear flows have been held alternately in the United States and Europe with the first and third being held at universities in eastern and western States, respectively. Continuing this pattern, the Fifth Symposium on Turbulent Shear Flows was held at Cornell University, Ithaca, New York, in August 1985. The meeting brought together more than 250 participants from around the world to present the results of new research on turbulent shear flows. It also provided a forum for lively discussions on the implications (practical or academic) of some of the papers. Nearly 100 formal papers and about 20 shorter communications in open forums were presented. In all the areas covered, the meeting helped to underline the vitality of current research into turbulent shear flows whether in experimental, theoretical or numerical studies. The present volume contains 25 of the original symposium presentations. All have been further reviewed and edited and several have been considerably extended since their first presentation. The editors believe that the selection provides papers of archival value that, at the same time, give a representative statement of current research in the four areas covered by this book: - Homogeneous and Simple Flows - Free Flows - Wall Flows - Reacting Flows Each of these sections begins with an introductory article by a distinguished worker in the field.
Download or read book Coherent Structures in Turbulent Mixing Layers written by Alberto D'Ovidio and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coherent Structures in a Simulated Turbulent Mixing Layer written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-16 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A direct numerical simulation of a plane turbulent mixing layer has been performed. The simulation was initialized using two turbulent velocity fields obtained from direct numerical simulation of a turbulent boundary layer at momentum thickness Reynolds number 300 (Spalart, 1988). The mixing layer is allowed to evolve long enough for self-similar linear growth to occur, with the visual thickness Reynolds number reaching 14,000. The simulated flow is examined for evidence of the coherent structures expected in a mixing layer (rollers and rib vortices). Before the onset of self-similar growth, such structures are present with properties similar to the corresponding laminar or transitional structures. In the self-similar growth regime, however, only the rollers are present with no indication of rib vortices and no indication of conventional pairing. This results in a reduction of mixing and layer growth. Moser, Robert D. and Rogers, Michael M. Ames Research Center NASA-TM-103980, A-92197, NAS 1.15:103980 RTOP 505-59-53...
Download or read book Coherent Structures in a Simulated Turbulent Mixing Layer written by and published by . This book was released on 1992 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence and Coherent Structures written by O. Métais and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Turbulent Mixing in Nonreactive and Reactive Flows written by S. Murthy and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence, mixing and the mutual interaction of turbulence and chemistry continue to remain perplexing and impregnable in the fron tiers of fluid mechanics. The past ten years have brought enormous advances in computers and computational techniques on the one hand and in measurements and data processing on the other. The impact of such capabilities has led to a revolution both in the understanding of the structure of turbulence as well as in the predictive methods for application in technology. The early ideas on turbulence being an array of complicated phenomena and having some form of reasonably strong coherent struc ture have become well substantiated in recent experimental work. We are still at the very beginning of understanding all of the aspects of such coherence and of the possibilities of incorporating such structure into the analytical models for even those cases where the thin shear layer approximation may be valid. Nevertheless a distinguished body of "eddy chasers" has come into existence. The structure of mixing layers which has been studied for some years in terms of correlations and spectral analysis is also getting better understood. Both probability concepts such as intermittency and conditional sampling as well as the concept of large scale structure and the associated strain seem to indicate possibilities of distinguishing and synthesizing 'engulfment' and molecular mixing.
Download or read book Coherent Structures in Turbulent Shear Layers and Relation to Mixing Reaction and Combustion written by CALIFORNIA UNIV BERKELEY COLL OF ENGINEERING. and published by . This book was released on 1986 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: A number of numerical analyses served as experiments which led to a broad range of ideas about the dynamics of mixing layer. One theme which emerged early was the adversary role of vorticity and of deformation - two quanities which attempt to subjugate each other and whose competition is the subject matter of the development and growth to the shear flow. Another strand of the work follows a number of instabilities (two and three dimensional) which lead to recognizable non-linear motions. A third focus of the work relates vorticity and the mixing of scalars. The work started out to attempt to explain striking experimental results and ended by making a number of predictions which have not yet been experimentally established. A significant fraction, though not all of the typical motions which are dynamically plausible in a shear layer have been examined and given simple analytic representation. Finally the basis for the effective control of the shear layer has been laid.
Download or read book Scalar Mixing and Coherent Structures in Simulations of the Plane Turbulent Mixing Layer written by Stephan Nicholas Hug and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simulation of Turbulent Flows with and without Combustion with Emphasis on the Impact of Coherent Structures on the Turbulent Mixing written by Cunha Galeazzo, Flavio Cesar and published by KIT Scientific Publishing. This book was released on 2016-10-14 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: The analysis of turbulent mixing in complex turbulent flows is a challenging task. The effective mixing of entrained fluids to a molecular level is a vital part of the dynamics of turbulent flows, especially when combustion is involved. The work has shown the limitations of the steady-state simulations and acknowledged the need of applying high-fidelity unsteady methods for the calculation of flows with pronounced unsteadiness promoted by large-scale coherent structures or other sources.
Download or read book The Coherent Structure of Turbulent Mixing Layers written by Luis Paulino Bernal and published by . This book was released on 1984 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coherent Structures in the Axisymmetric Turbulent Jet Mixing Layer written by Mark N. Glauser and published by . This book was released on 1987 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transport and Coherent Structures in Wall Turbulence written by Sedat Tardu and published by John Wiley & Sons. This book was released on 2014-10-06 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wall bounded turbulent flows are of major importance in industrial and environmental fluid mechanics. The structure of the wall turbulence is intrinsically related to the coherent structures that play a fundamental role in the transport process. The comprehension of their regeneration mechanism is indispensable for the development of efficient strategies in terms of drag control and near wall turbulence management. This book provides an up-to-date overview on the progress made in this specific area in recent years.
Download or read book Fluid Vortices written by Sheldon Green and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 905 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluid Vortices is a comprehensive, up-to-date, research-level overview covering all salient flows in which fluid vortices play a significant role. The various chapters have been written by specialists from North America, Europe and Asia, making for unsurpassed depth and breadth of coverage. Topics addressed include fundamental vortex flows (mixing layer vortices, vortex rings, wake vortices, vortex stability, etc.), industrial and environmental vortex flows (aero-propulsion system vortices, vortex-structure interaction, atmospheric vortices, computational methods with vortices, etc.), and multiphase vortex flows (free-surface effects, vortex cavitation, and bubble and particle interactions with vortices). The book can also be recommended as an advanced graduate-level supplementary textbook. The first nine chapters of the book are suitable for a one-term course; chapters 10--19 form the basis for a second one-term course.
Download or read book The Structure of Turbulent Shear Flow written by A. A. R. Townsend and published by Cambridge University Press. This book was released on 1976 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: Develops a physical theory from the mass of experimental results, with revisions to reflect advances of recent years.
Download or read book Advances in Turbulence written by Genevieve Comte-Bellot and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 597 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since 1964 the main function of the European Mechanics Committee has been to arrange Euromech Colloquia. These are three- or four-day meetings for the discussion of current research on a specified and relatively narrow topic in mechanics, by about 50 specialists chosen for their active involvement in research in that topic. The organization of each Euromech Colloquium is entrusted by the Committee to one or two selected scientists of repute in the field, and these organizers are enjoined to achieve a friendly and informal forum for discussion, with a minimum of paper work and expenditure. Over 220 Euromech Colloquia have been held since 1964 (about 40 each in France, West Germany and Britain and the remainder in 18 countries in both western and eastern Europe) on a wide range of topics drawn from the mechanics of solid materials, hydrodynamics, gas dynamics and mechanical systems. The Committee believes that collectively, Euromech Colloquia have made a significant contribution to the exchange of ideas on topics in mechanics within Europe and have thereby helped to overcome the barriers to easy scientific communication in that sorely divided continent. A few years ago the European Mechanics Committee turned its atten tion to the possible need for European conferences on a larger scale than Euromech Colloquia.
Download or read book Transmission of Light Through a Turbulent Mixing Layer written by and published by . This book was released on 1992 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light transmission through incompressible gaseous turbulent mixing layers was investigated with the objective of understanding the effects of large-scale coherent structures and mixing transition on the optical quality of the mixing layer. Experiments were done in a vertically flowing mixing layer which is enclosed inside a pressure tank and fed by two banks of high-pressure gas bottles. The study considered both the unequal density (high-speed He and low-speed N2) and equal density (high-speed N2 and low-speed He-Ar) cases; the mixing of dissimilar gases is the source of the optical aberrations. Large-scale Reynolds numbers ranged between 3500 and 80000 over pressures from 2 to 6 bar. Light transmission characteristics were first studied qualitatively using a network of thin sheets of short-exposure (approx. l microsec) white light which were aberrated by the mixing layer and then imaged directly onto photographic film. Light transmission characteristics were then studied quantitatively using a lateral effect detector to dynamically track a thin He-Ne laser beam as it wandered under the influence of the passing coherent structures. The study found that the spanwise coherent structures generate systematic deflections of the light beam in the streamwise direction; the greatest deflections occur near the trailing edges of the structures at a formation called the cusp, where the high- speed fluid and low-speed fluid are entrained into the vortex core. The streamwise coherent structures, which form later in the mixing layer's development than the spanwise structures, generate substantial beam deflections in the spanwise direction which are closely associated with the streamwise streaks in plan-view shadowgraphs. ... Aero-optics, Turbulent structure.
Download or read book Identification of Coherent Vortical Structures in a Turbulent Mixing Layer by an Orthogonal Decomposition written by Daniel Grünbaum and published by . This book was released on 1986 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
