Download or read book Modeling of Turbulent Transport in the Surface Layer written by George Louis Smith and published by . This book was released on 1973 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Climate Change and Terrestrial Ecosystem Modeling written by Gordon Bonan and published by Cambridge University Press. This book was released on 2019-02-21 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides an essential introduction to modeling terrestrial ecosystems in Earth system models for graduate students and researchers.
Download or read book Second Order Modeling of Turbulent Transport in the Surface Mixed Layer written by J. L. Lumley and published by . This book was released on 1984 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model for the simultaneous transport of heat and water vapor is presented. In an effort to resolve the structure of the entrainment region at the inversion base, models are constructed so as to satisfy realizability as far as possible. Density anomaly and water vapor mixture fraction (specific humidity) are taken as the basic variables. Algebraic expressions for the third moments are derived from first principles, and contain no adjustable constants. Separate equations are carried for the dissipation of each variance, constructed to give rational behavior of all time scale ratios. New forms for relaxation and cross-dissipation terms are constructed in such a way as to guarantee realizability. We describe how realizability was used as a tool to construct these models. We present preliminary results without mean velocity gradients for a dry surface mixed layer leaving the land and starting over water, producing a stable internal humidity boundary layer, but with large fluxes of sensible heat and water vapor (local advection). (Reprints).
Download or read book Fundamentals Of Turbulence Modelling written by Ching Jen Chen and published by CRC Press. This book was released on 1997-12-01 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focuses on the second-order turbulence-closure model and its applications to engineering problems. Topics include turbulent motion and the averaging process, near-wall turbulence, applications of turbulence models, and turbulent buoyant flows.
Download or read book Turbulence in the Ocean written by Monin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Four years have elapsed since the preparation of the original Russian version of this book. This is a long time when dealing with such actively expanding fields of oceanography as research into small-scale structures and the investigation of hydro physical processes. Over this period new quick-response devices have been developed and successfully used for measurements taken in various ocean areas. Improvements in high-frequency meters used to measure hydrophysical parameters has enabled workers to obtain more accurate absolute values of the fluctuations measured by such devices. In view of this scientific progress, some of the ideas presented in this book now require additional explanation. Great care should be used in dealing with the absolute fluctuation values of hydro physical fields, since the methods used for the determination of the accuracy of the high-frequency measuring devices have been imperfect in the past. Never theless, it would appear that the results of the investigations summarized in this book have not lost their importance, and that the established laws governing small-scale pro cesses in the ocean are of a sufficiently universal nature and, as such, have not been shattered with the qualitative and quantitative advances in devices used for measurements taken in oceans. The authors feel that their work is of interest to English-speaking readers. The appearance of the English translation of the book is, to a very large extent, due to the tremendous amount of editing work brilliantly done by Prof. H. Tennekes.
Download or read book Transport and Diffusion in Turbulent Fields written by Hadassah Kaplan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 35th OHOLO Conference, which provided the basis for the present book covered a broad range of topics. Basic studies and newly developed methods in modeling atmospheric flows are discussed, besides analyses of concentration fluctuations in different atmospheric conditions, and techniques of data acquisition. The book gives an excellent state-of-the-art impression of the situation in turbulent diffusion and transport.
Download or read book Turbulent Flows written by Jean Piquet and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 767 pages. Available in PDF, EPUB and Kindle. Book excerpt: obtained are still severely limited to low Reynolds numbers (about only one decade better than direct numerical simulations), and the interpretation of such calculations for complex, curved geometries is still unclear. It is evident that a lot of work (and a very significant increase in available computing power) is required before such methods can be adopted in daily's engineering practice. I hope to l"Cport on all these topics in a near future. The book is divided into six chapters, each· chapter in subchapters, sections and subsections. The first part is introduced by Chapter 1 which summarizes the equations of fluid mechanies, it is developed in C~apters 2 to 4 devoted to the construction of turbulence models. What has been called "engineering methods" is considered in Chapter 2 where the Reynolds averaged equations al"C established and the closure problem studied (§1-3). A first detailed study of homogeneous turbulent flows follows (§4). It includes a review of available experimental data and their modeling. The eddy viscosity concept is analyzed in §5 with the l"Csulting ~alar-transport equation models such as the famous K-e model. Reynolds stl"Css models (Chapter 4) require a preliminary consideration of two-point turbulence concepts which are developed in Chapter 3 devoted to homogeneous turbulence. We review the two-point moments of velocity fields and their spectral transforms (§ 1), their general dynamics (§2) with the particular case of homogeneous, isotropie turbulence (§3) whel"C the so-called Kolmogorov's assumptions are discussed at length.
Download or read book Tackling Turbulent Flows in Engineering written by Anupam Dewan and published by Springer Science & Business Media. This book was released on 2010-10-23 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: The emphasis of this book is on engineering aspects of fluid turbulence. The book explains for example how to tackle turbulence in industrial applications. It is useful to several disciplines, such as, mechanical, civil, chemical, aerospace engineers and also to professors, researchers, beginners, under graduates and post graduates. The following issues are emphasized in the book: - Modeling and computations of engineering flows: The author discusses in detail the quantities of interest for engineering turbulent flows and how to select an appropriate turbulence model; Also, a treatment of the selection of appropriate boundary conditions for the CFD simulations is given. - Modeling of turbulent convective heat transfer: This is encountered in several practical situations. It basically needs discussion on issues of treatment of walls and turbulent heat fluxes. - Modeling of buoyancy driven flows, for example, smoke issuing from chimney, pollutant discharge into water bodies, etc
Download or read book Turbulence in the Atmosphere written by John C. Wyngaard and published by Cambridge University Press. This book was released on 2010-01-28 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on his over forty years of research and teaching, John C. Wyngaard's textbook is an excellent up-to-date introduction to turbulence in the atmosphere and in engineering flows for advanced students, and a reference work for researchers in the atmospheric sciences. Part I introduces the concepts and equations of turbulence. It includes a rigorous introduction to the principal types of numerical modeling of turbulent flows. Part II describes turbulence in the atmospheric boundary layer. Part III covers the foundations of the statistical representation of turbulence and includes illustrative examples of stochastic problems that can be solved analytically. The book treats atmospheric and engineering turbulence in a unified way, gives clear explanation of the fundamental concepts of modeling turbulence, and has an up-to-date treatment of turbulence in the atmospheric boundary layer. Student exercises are included at the ends of chapters, and worked solutions are available online for use by course instructors.
Download or read book Turbulence Models and Their Application in Hydraulics written by Wolfgang Rodi and published by Routledge. This book was released on 2017-11-01 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an introduction to the subject of turbulence modelling in a form easy to understand for anybody with a basic background in fluid mechanics, and it summarizes the present state of the art. Individual models are described and examined for the merits and demerits which range from the simple Prandtl mixing length theory to complex second order closure schemes.
Download or read book Spectral Modeling of an Idealized Atmospheric Surface Layer written by Kaighin Alexander McColl and published by . This book was released on 2017 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Almost all of humanity resides in the atmospheric surface layer (ASL), so its state (e.g., temperature, humidity, wind velocity) is relevant to a range of applications in human health, agriculture, and ecosystem health. However, the ASL is turbulent, and therefore characterized by complex dynamics across a wide range of spatial and temporal scales. Explicitly modelling turbulent motions in the ASL at all scales is computationally expensive and beyond current capabilities. In this thesis, a framework is proposed for parsimoniously modelling a broad range of turbulent motions in wall-bounded turbulent flows such as the ASL, using spectra of turbulent fluctuations as inputs. Turbulent spectra contain information on turbulent motions across scales, and are constrained by theory and observations. By propagating spectra through a cospectral budget, a model of the mean velocity profile (MVP) is obtained. Comparison with a direct numerical simulation (DNS) of a neutral channel flow reveals a good correspondence between the MVPs of the cospectral budget model and DNS, provided the pressure-decorrelation model in the cospectral budget includes established effects of wall-blocking. This work demonstrates that the distribution of turbulent vertical velocity fluctuations (the 'microstate' of the flow) contains sufficient information to generate the MVP (the 'macrostate' of the flow). It also establishes a link between two previously unrelated areas of the turbulence literature: 1) Kolmogorov's scaling of the turbulent energy spectrum, derived for homogeneous, isotropic turbulence and 2) the 'law of the wall' in wall-bounded turbulence. The cospectral budget model is then extended to the case where the wall-bounded flow is heated from below, as in an unstable ASL. The MVP and mean buoyancy profile (MBP) of the cospectral budget model and the DNS agree qualitatively, with remaining differences attributable to neglected terms in the cospectral budget, and the low Reynolds number of the DNS. The normalized turbulent statistics of the heated duct flow DNS agree surprisingly well with ASL measurements, despite the low Reynolds number of the DNS and other differences. Treating the DNS as an idealized ASL, a spectral model is derived to describe the partitioning of turbulent kinetic and potential energy between turbulent transport of heat and momentum in the ASL. The model reproduces observed dissimilarity between turbulent heat and momentum transport in unstable conditions. It attributes the dissimilarity to contributions from large eddies in turbulent heat transport, which are largely ignored in existing ASL parameterizations in weather and climate models.
Download or read book Application of Turbulence Modeling to Predict Surface Heat Transfer in Stagnation Flow Region of Circular Cylinder written by Chi-Rong Wang and published by . This book was released on 1987 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Transport Model of Wind Shear in Thunderstorm Gust Fronts and Warm Fronts written by W. S. Lewellen and published by . This book was released on 1978 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Flows written by G. Biswas and published by CRC Press. This book was released on 2002 with total page 478 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 Statistical Theory and Modeling for Turbulent Flows written by P. A. Durbin and published by Wiley-Blackwell. This book was released on 2001-03-12 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most natural and industrial flows are turbulent. The atmosphere and oceans, automobile and aircraft engines, all provide examples of this ubiquitous phenomenon. In recent years, turbulence has become a very lively area of scientific research and application, and this work offers a grounding in the subject of turbulence, developing both the physical insight and the mathematical framework needed to express the theory. Providing a solid foundation in the key topics in turbulence, this valuable reference resource enables the reader to become a knowledgeable developer of predictive tools. This central and broad ranging topic would be of interest to graduate students in a broad range of subjects, including aeronautical and mechanical engineering, applied mathematics and the physical sciences. The accompanying solutions manual to the text also makes this a valuable teaching tool for lecturers and for practising engineers and scientists in computational and experimental and experimental fluid dynamics.
Download or read book Modeling Complex Turbulent Flows written by Manuel D. Salas and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence modeling both addresses a fundamental problem in physics, 'the last great unsolved problem of classical physics,' and has far-reaching importance in the solution of difficult practical problems from aeronautical engineering to dynamic meteorology. However, the growth of supercom puter facilities has recently caused an apparent shift in the focus of tur bulence research from modeling to direct numerical simulation (DNS) and large eddy simulation (LES). This shift in emphasis comes at a time when claims are being made in the world around us that scientific analysis itself will shortly be transformed or replaced by a more powerful 'paradigm' based on massive computations and sophisticated visualization. Although this viewpoint has not lacked ar ticulate and influential advocates, these claims can at best only be judged premature. After all, as one computational researcher lamented, 'the com puter only does what I tell it to do, and not what I want it to do. ' In turbulence research, the initial speculation that computational meth ods would replace not only model-based computations but even experimen tal measurements, have not come close to fulfillment. It is becoming clear that computational methods and model development are equal partners in turbulence research: DNS and LES remain valuable tools for suggesting and validating models, while turbulence models continue to be the preferred tool for practical computations. We believed that a symposium which would reaffirm the practical and scientific importance of turbulence modeling was both necessary and timely.
Download or read book Prediction of Turbulent Flows written by Geoff Hewitt and published by Cambridge University Press. This book was released on 2005-06-08 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: The prediction of turbulent flows is of paramount importance in the development of complex engineering systems involving flow, heat and mass transfer, and chemical reactions. Arising from a programme held at the Isaac Newton Institute in Cambridge, this volume reviews the current situation regarding the prediction of such flows through the use of modern computational fluid dynamics techniques, and attempts to address the inherent problem of modelling turbulence. In particular, the current physical understanding of such flows is summarised and the resulting implications for simulation discussed. The volume continues by surveying current approximation methods whilst discussing their applicability to industrial problems. This major work concludes by providing a specific set of guidelines for selecting the most appropriate model for a given problem. Unique in its breadth and critical approach, this book will be of immense value to experienced practitioners and researchers, continuing the UK's strong tradition in fluid dynamics.
