Download or read book An Investigation of Larger Scale Coherent Structures in Fully Developed Turbulent Boundary Layers written by Nick Hutchins and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Behaviour of Energetic Coherent Structures in Turbulent Pipe Flow at High Reynolds Numbers written by Zeinab Hallol and published by Cuvillier Verlag. This book was released on 2021-10-26 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, coherent turbulent structures in turbulent pipe flow are investigated at relatively high Reynolds numbers and study their association in both total kinetic energy and Reynolds shear stress. Experimental investigations have been performed in Cottbus Large Pipe test facility (CoLaPipe) for pipe flow over a wide range of Reynolds number 8 × 104 ≤ ReD ≤ 1 × 106, located at the Aerodynamics and Fluid Mechanics Department, Brandenburg University of Technology Cottbus- Senftenberg (BTU). The first part of the thesis focuses on determining the contribution of the coherent structures using one-dimensional spectral analysis and assessing the structures behaviour in the outer region of pipe flow using high spatial resolution Hot-wire measurement up to 30kHz. The results of the power and pre-multiplied spectrum of stream-wise velocity indicate that the wavelength value of very large scale motions (VLSMs) acquires 19R at a maximum Reynolds number range ReD=1 × 106 (Reτ =19000). On the other hand, large-scale motions have a wavelength value of 3R over different Reynolds number range. Regarding the identified wavelength values, it is observed that contribution to energy for structures greater than 3R carries 55% of total kinetic energy. In addition, temporal-spatial resolution using the High-speed PIV measurements has been performed in CoLaPipe to estimate the contribution magnitude of stream-wise/wall-normal velocity fluctuations to total kinetic energy and Reynolds shear stress in the logarithmic and outer layer.
Download or read book On the Large Scale Structure of Turbulence in Boundary Layer and Shear Flows written by M. A. Badri Narayanan and published by . This book was released on 1982 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: The basic understanding of the physics of turbulence has undergone many radical changes in the last few years. Turbulent fluctuations which were considered to be purely random in nature is no more accepted to behave in that fashion but made up of somewhat coherent and orderly structures mixed with noise like random disturbances. The major difficulty experienced in the experimental investigations is the identification of these coherent structures from the overall signal. New methods are being developed to identify them. These orderly motions are large in scale and seem to play an important role in the dynamics of the mixing and the transport processes which are the essential features of turbulence. In this paper the properties of the large scale fluctuations in boundary layers as well as in shear flows are discussed. (Author).
Download or read book Coherent Flow Structures at Earth s Surface written by Jeremy G. Venditti and published by John Wiley & Sons. This book was released on 2013-08-28 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt: An expert review of recent progress in the study of turbulent flows with a focus on recently identified organized structures. This book reviews the recent progress in the study of the turbulent flows that sculpt the Earth’s surface, focusing in particular on the organized structures that have been identified in recent years within turbulent flows. These coherent flow structures can include eddies or vortices at the scale of individual grains, through structures that scale with the flow depth in rivers or estuaries, to the large-scale structure of flows at the morphological or landform scale. These flow structures are of wide interest to the scientific community because they play an important role in fluid dynamics and influence the transport, erosion and deposition of sediment and pollutants in a wide variety of fluid flow environments. Scientific knowledge of these structures has improved greatly over the past 20 years as computational fluid dynamics has come to play an increasing important part in building our understanding of coherent flow structures across a broad range of scales. Chapters comprise a series of major, invited papers and a selection of the most novel, innovative papers presented at the second Coherent Flow Structures Conference held August 3-5, 2011 at Simon Fraser University in Burnaby, British Columbia. Chapters focus on six major themes: Dynamics of coherent flow structures (CFS) in geophysical flows Interaction of turbulent flows, vegetation and ecological habitats Coherent structure of atmospheric flows Numerical modeling of coherent flow structures Turbulence in open channel flows Coherent flow structures, sediment transport and morphological feedbacks.
Download or read book Workshop on Coherent Structure of Turbulent Boundary Layers written by Charles Robert Smith and published by . This book was released on 1981 with total page 1116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Whither Turbulence and Big Data in the 21st Century written by Andrew Pollard and published by Springer. This book was released on 2016-08-30 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides a snapshot of the current and future trends in turbulence research across a range of disciplines. It provides an overview of the key challenges that face scientific and engineering communities in the context of huge databases of turbulence information currently being generated, yet poorly mined. These challenges include coherent structures and their control, wall turbulence and control, multi-scale turbulence, the impact of turbulence on energy generation and turbulence data manipulation strategies. The motivation for this volume is to assist the reader to make physical sense of these data deluges so as to inform both the research community as well as to advance practical outcomes from what is learned. Outcomes presented in this collection provide industry with information that impacts their activities, such as minimizing impact of wind farms, opportunities for understanding large scale wind events and large eddy simulation of the hydrodynamics of bays and lakes thereby increasing energy efficiencies, and minimizing emissions and noise from jet engines. Elucidates established, contemporary, and novel aspects of fluid turbulence - a ubiquitous yet poorly understood phenomena; Explores computer simulation of turbulence in the context of the emerging, unprecedented profusion of experimental data,which will need to be stewarded and archived; Examines a compendium of problems and issues that investigators can use to help formulate new promising research ideas; Makes the case for why funding agencies and scientists around the world need to lead a global effort to establish and steward large stores of turbulence data, rather than leaving them to individual researchers.
Download or read book Coherent Structures Chaos and the Role of Modern Dynamics in Turbulent Shear Flows written by H. Fasel and published by . This book was released on 1990 with total page 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 2014-09-10 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 Investigation of the Turbulence Producing Structures in the Boundary Layer written by Stephen Jay Kline and published by . This book was released on 1991 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Progress in Turbulence written by Joachim Peinke and published by Springer Science & Business Media. This book was released on 2006-05-06 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: Besides turbulence, there is hardly any other scientific topic which has been considered a prominent scientific challenge for such a long time. The special interest in turbulence is not only based on it being a difficult scientific problem but also on its meaning in the technical world and our daily life. This carefully edited book comprises recent basic research as well as research related to the applications of turbulence. Therefore, both leading engineers and physicists working in the field of turbulence were invited to the iTi Conference on Turbulence held in Bad Zwischenahn, Gemany 21st - 24th of September 2003. Topics discussed include, for example, scaling laws and intermittency, thermal convection, boundary layers at large Reynolds numbers, isotropic turbulence, stochastic processes, passive and active scalars, coherent structures, numerical simulations, and related subjects.
Download or read book A Dynamical System coherent Structure Approach to the Fully Developed Turbulent Wall Layer written by Nadine Aubry and published by . This book was released on 1987 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Les Investigation of Coherent Structures in Boundary Layers and Wakes Volume III Development of a Parallel Unstructured Grid Les Code written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the present investigation is to assess the feasibility of simulating and studying coherent structures in turbulent shear layers, making use of Large Eddy Simulations (LES). Volumes I and II were devoted to the investigation of coherent structures in LES solutions obtained using a structured-grid finite-difference code, first in an attached turbulent flow, and then in the wake behind a square cylinder. The structured grid code used in Parts I & II, despite its multi-domain capability, is limited in the domain geometries it can handle. The third part of the work was therefore devoted to the development of an unstructured grid LES code able to compute turbulent flows over arbitrary two-dimensional geometries. A combined finite-element/Fourier spectral space discretization scheme was selected, as it combines optimally the geometrical flexibility provided by the finite element scheme and the computational efficiency resulting from the decomposition in Fourier modes in the outof-plane direction. Indeed, thanks to this decomposition, and a suitable treatment of the nonlinear convective terms, the 3D flow problem is transformed into a series of 2D problems in Fourier space, completely decoupled within each time step. In addition, the decoupling allows for an easy parallelization by partitioning the work in Fourier space rather than physical space. Also, the stabilized finite element technique selected for the in-plane discretization provides an accuracy superior to its finite volume counterpart on the same unstructured grid and for the same discretization stencil.
Download or read book A Review of Quasi coherent Structures in a Numerically Simulated Turbulent Boundary Layer written by and published by . This book was released on 1989 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigation of coherent structures in turbulent boundary layers written by Candace Elaine Wark and published by . This book was released on 1989 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
