Download or read book A Theory of Turbulence in a Homogeneous Fluid Induced by an Oscillating Grid written by Robert R. Long and published by . This book was released on 1977 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent studies of turbulence indicate that the root-mean-square horizontal velocity sigma(u) is proportional to the oscillation frequency f and is inversely proportional to distance from the grid, and that the integral length scale l is proportional to this distance and independent of f. A theoretical model is based on the Navier-Stokes equations and the no-slip boundary condition but contains no other assumptions. The statistically steady behavior is as observed in the experiment. In the unsteady case, the front separating turbulent and non-turbulent fluid propagates at a speed inversely proportional to the square root of time. The problem has importance with respect to the mixed layer in the upper ocean or in the lower atmosphere. The present model does not consider buoyancy effects but if a passive contaminant is present the mean concentration is governed by the one-dimensional diffusion equation with constant turbulent coefficient of diffusion.
Download or read book Advances in Turbulence VI written by S. Gavrilakis and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 643 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Turbulence VI presents an update on the state of turbulence research with some bias towards research in Europe, since it represents an almost complete collection of the paper presentations at the Sixth European Turbulence Conference, sponsored by EUROMECH, ERCOFTAC and COST, and held at the Swiss Federal Institute of Technology in Lausanne, July 2-5, 1996. The problem of transition, together with the structural description of turbulence, and the scaling laws of fully developed turbulence have continued to receive most attention by the research community and much progress has been made since the last European Turbulence Conference in 1994. The volume is thus geared towards specialists in the area of flow turbulence who could not attend the conference, as well as anybody who wishes quickly to assess the most active current research areas and the groups associated with them.
Download or read book The Ocean Surface written by Y. Toba and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 581 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 Advances in Turbulence IV written by F.T. Nieuwstadt and published by Springer Science & Business Media. This book was released on 1993-06-30 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: The European Turbulence Conferences have been organized under the auspices of the European Mechanics Committee (Euromech) to provide a forum for discussion and exchange of recent and new results in the field of turbulence. The first conference was organized in Lyon in 1986 with 152 participants. The second and third conferences were held in Berlin (1988) and Stockholm (1990) with 165 and 172 participants respectively. The fourth was organized in Delft from 30 June to 3 July 1992 by the J.M. Burgers Centre. There were 214 participants from 22 countries. This steadily growing number of participants demonstrates both the success and need for this type of conference. The main topics of the Fourth European Turbulence Conference were: Dynamical Systems and Transition; Statistical Physics and Turbulence; Experiments and Novel Experimental Techniques; Particles and Bubbles in Turbulence; Simulation Methods; Coherent Structures; Turbulence Modelling and Compressibility Effects. In addition a special session was held on the subject of CeBular Automata. Each of the sessions was introduced with a survey lecture. The lecturers were: W. Eckhaus, AJ. Libchaber, L. Katgerman, F. Durst, M. Lesieur, B. Legras, D.G. Dritschel and P. Bradshaw. The contributions of the participants were subdivided into oral and poster presentations. In addition to the normal program, some Speciai Interest Groups of Ercoftac (European Research Community on Flow, Turbulence and Combustion) presented their research activities in the form of a poster.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1975 with total page 978 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fjord Oceanography written by Howard Freeland and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 691 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fjords are deep, glacia11y carved estuaries that are pecu1iar to certain coast1ines, and have severa1 characteristics that dist inguish them from sha110wer embayments. At higher latitudes they indent the western coast1ines of Scandinavia, North and South America, and New Zea1and. They are a1so a common feature of much of the arctic coast1ine. The papers contained in this vo1ume were presented at a workshop funded by the NATO Advanced Studies Institute in Victoria, British Co1umbia. It may seem curious to the reader that this specia1 c1ass of estuaries shou1d have attracted an international gathering of oceanographers from severa1 different discip1ines. The reas on for this interest stems from both practica1 and scientific considerations. On the one hand, fjords are a feature common to the coast1ines of severa1 countries that depend heavi1y on the oceans for communication, fisheries and other resources. The impact of man's activities on these coasts has created a demand for new know1edge of the physica1, bio10gica1 and chemica1 aspects of fjords. Sometimes man's inf1uence on the ocean is intentiona1 as, for examp1e, in the artificia1 contro1 of ice cover; often it is the more insidious bui1d-up of toxic wastes that is of concern. These prob1ems are particu1ar1y acute where the conf1icting demands of fisheries, industria1 deve10pment and re creation meet in a sing1e fjord; and indeed, this is a common occurence a10ng severa1 of the fjords in Scandinavia and Canada.
Download or read book Vortex Structures in a Stratified Fluid written by Sergey I. Voropayev and published by CRC Press. This book was released on 1994-05-15 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fully systematic treatment of the dynamics of vortex structures and their interactions in a viscous density stratified fluid is provided by this book. The various compact vortex structures such as monopoles, dipoles, quadrupoles, as well as more complex ones are considered theoretically from a physical point of view. Another essential feature of the book is the close combination of theoretical analyses with numerous examples of real flows. The book further provides real physical insight and base for postgraduate students specializing in geophysical and applied fluid dynamics. Among the family of vortex structures considered in the book, the most remarkable are the vortex dipoles. These are fundamental elements of the complex chaotic flows associated with the term 'two-dimensional turbulence'. The appearance of these structures in initially chaotic flows is currently of great interest because of a myriad of geophysical applications. Specific examples include the mushroom-like currents discovered from satellite images of the upper ocean. The book is well illustrated with many original photographs (some in colour) and diagrams.
Download or read book Oscillating Grid Turbulence and Its Influence on Gas Liquid Mass Transfer and Mixing in Non Newtonian Media written by Tom Lacassagne and published by . This book was released on 2018 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of turbulence induced mass transfer at the interface between a gas and a liquid is of great interest in many environmental phenomena and industrial processes. Even though this issue has already been studied for several decades, its understanding is still not good enough to create realistic models (RANS or sub-grid LES), especially when considering a liquid phase with a complex rheology. This experimental work aims at studying fundamental aspects of turbulent mass transfer at a flat interface between carbon dioxide and a Newtonian or non-Newtonian liquid, stirred by homogeneous and quasi isotropic turbulence. Non-Newtonian fluids studied are aqueous solutions of a model polymer, Xanthan gum (XG), at various concentrations, showing viscoelastic and shear-thinning properties. Optical techniques for the acquisition of the liquid phase velocity field (Stereoscopic Particle Image Velocimetry, SPIV) and dissolved gas concentration field (Inhibited Planar Laser Induced Fluorescence, I-PLIF) are for the first time coupled, keeping a high spatial resolution, to access velocity and concentration statistics in the first few millimetres under the interface. A new version of I-PLIF is developed. It is designed to be more efficient for near surface measurements, but its use can be generalized to other single or multiphase mass transfer situations. Bottom shear turbulence in the liquid phase is generated by an oscillating grid apparatus. The mechanisms of turbulence production and the characteristics of oscillating grid turbulence (OGT) are studied. The importance of the oscillatory component of turbulence is discussed. A mean flow enhancement effect upon polymer addition is evidenced. The mechanisms of turbulent mass transfer at a flat interface are finally observed in water and low concentration polymer solutions. A conditional analysis of turbulent mass fluxes allows to distinguish the type of events contributing to mass transfer and discuss their respective impact in water and polymer solutions.
Download or read book Hydrodynamics Theory and Applications written by A. T. Chwang and published by Taylor & Francis Group. This book was released on 1996 with total page 784 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 1989 with total page 1148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Breaking Waves written by Michael L. Banner and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wave breaking is a commonly occurring phenomena associated with wave motion in fluids, often inducing significant effects which are of fundamental and technological importance, A familiar illustration is provided with white-capping and microbreaking of the wind-driven ocean sUrface waves, which is believed to play an important part in the transfers of momentum, mass and heat across the air-sea interface, as well as in the production of underwater ambient noise and augmented microwave backscatter. The enhanced hydrodynamic forces associated with the breaking of the more energetic ocean wave components constitute a significant challenge in ocean engineering, coastal engineering and naval architecture. Other less conspicuous but equally important manifestations are the breaking of internal waves and the fila mentation of vorticity interfaces. Despite recent theoretical and observational progress towards a more complete understanding of wave breaking, mathematical descriptions of its onset and consequences are presently lacking. The aim of this Symposium was to bring together theoretical and observational expertise, with the goal of determining the current state of knowledge of wave breaking and providing a stimulus to future research. The Symposium focused on water waves of all scales from capillary waves to ocean swell, but also considered internal waves and the filamentation of vorticity interfaces. Specific topics included were: Fundamental theoretical studies; wave instabilities; routes to breaking. Models of wave breaking. Field observations, including statistical information. Laboratory studies. Shoaling waves, breaking waves on currents, breaking induced by the motion of a ship.
Download or read book IUTAM Symposium on Simulation and Identification of Organized Structures in Flows written by J.N. Sørensen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains reviewed papers from the 1997 IUTAM Symposium, presenting the latest results from leading scientists within the field of detection and simulation of organized flow structures. It describes various aspects of complex, organized flow motion, including topics from decomposition techniques to topological concepts.
Download or read book R D Abstracts written by Technology Reports Centre (Great Britain) and published by . This book was released on 1977 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum Turbulence written by Shu-Chen Liu and published by LAP Lambert Academic Publishing. This book was released on 2009-09 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: QUANTUM TURBULENCE : DECAY OF GRID TURBULENCE IN A DISSIPATIONLESS FLUID We produced grid turbulence in liquid helium at 520 mK to compare with classical experiments and theories. Above T = 1 K, with viscosity present, it has been shown that grid turbulence is equivalent to homogeneous isotropic turbulence in a classical fluid. We seek to investigate the nature of grid turbulence when viscosity is zero. Specifically, in the absence of viscosity in a quantum fluid, through what path does the turbulence decay? To produce grid turbulence, a magnetically shielded superconducting linear motor was designed and built to accelerate and decelerate the grid rapidly in a short distance (~ 1 mm), and achieve glide speeds up to 1 m/s, when driven with the properly shaped current pulse. We measured the decay of the turbulence produced by calorimetry technique. Recent theory suggests the decay occurs through a Kelvin-wave cascade on the vortex lines which couples the initially large turbulent eddies to the short wavelength phonon spectrum of the liquid, yielding a characteristic rate of temperature rise. Initial measurements support the Kelvin wave cascade theory.
Download or read book Mechanics of Real Fluids written by Matiur Rahman and published by WIT Press. This book was released on 2011 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book on an important area of applied mathematics is a compendium of the work of many pioneering authors and of research works from throughout the author's career ... It is intended to provide background for young scientists and graduate students as well as applied mathematicians and professional engineers. Some knowledge of vector calculus including the integral theorems such as Green's theorem, Stokes's theorem and divergence theorem is assumed on the part of the reader. Isotropic tensor calculus is used sparingly in some chapters. A famliarity with the Bessel functions, Legendre polynomials and hypergeometric functions is also expected" -- Back cover.
Download or read book Turbulence written by Frans T.M. Nieuwstadt and published by Springer. This book was released on 2016-07-04 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a general introduction to the topic of turbulent flows. Apart from classical topics in turbulence, attention is also paid to modern topics. After studying this work, the reader will have the basic knowledge to follow current topics on turbulence in scientific literature. The theory is illustrated with a number of examples of applications, such as closure models, numerical simulations and turbulent diffusion, and experimental findings. The work also contains a number of illustrative exercises Review from the Textbook & Academic Authors Association that awarded the book with the 2017 Most Promising New Textbook Award: “Compared to other books in this subject, we find this one to be very up-to-date and effective at explaining this complicated subject. We certainly would highly recommend it as a text for students and practicing professionals who wish to expand their understanding of modern fluid mechanics.”
