Download or read book Digital Simulation of Turbulence in the Atmospheric Boundary Layer written by Canada. Service de l'environnement atmosphérique and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multi component Linear Digital Simulation of Atmospheric Boundary Layer Turbulence written by Canada. Service de l'environnement atmosphérique and published by . This book was released on 1977 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A SIMULATION OF TURBULENCE IN THE ATMOSPHERIC BOUNDARY LAYER written by Bryan Richard Kerman and published by . This book was released on 1975 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simulation of Atmospheric Boundary Layer Turbulence with Cross spectrum and Large scale Eddy Structure written by Ehssanollah F. Arman and published by . This book was released on 1986 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analyses of Turbulence in the Neutrally and Stably Stratified Planetary Boundary Layer written by Cedrick Ansorge and published by Springer. This book was released on 2016-10-04 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a study of strong stratification and turbulence collapse in the planetary boundary layer, opening a new avenue in this field. It is the first work to study all regimes of stratified turbulence in a unified simulation framework without a break in the paradigms for representation of turbulence. To date, advances in our understanding and the parameterization of turbulence in the stable boundary layer have been hampered by difficulties simulating the strongly stratified regime, and the analysis has primarily been based on field measurements. The content presented here changes that paradigm by demonstrating the ability of direct numerical simulation to address this problem, and by doing so to remove the uncertainty of turbulence models from the analysis. Employing a stably stratified Ekman layer as a simplified physical model of the stable boundary layer, the three stratification regimes observed in nature— weakly, intermediately and strongly stratified—are reproduced, and the data is subsequently used to answer key, long-standing questions. The main part of the book is organized in three sections, namely a comprehensive introduction, numerics, and physics. The thesis ends with a clear and concise conclusion that distills specific implications for the study of the stable boundary layer. This structure emphasizes the physical results, but at the same time gives relevance to the technical aspects of numerical schemes and post-processing tools. The selection of the relevant literature during the introduction, and its use along the work appropriately combines literature from two research communities: fluid dynamics, and boundary-layer meteorology.
Download or read book The Atmospheric Boundary Layer written by J. R. Garratt and published by Cambridge University Press. This book was released on 1994-04-21 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book gives a comprehensive and lucid account of the science of the atmospheric boundary layer (ABL). There is an emphasis on the application of the ABL to numerical modelling of the climate. The book comprises nine chapters, several appendices (data tables, information sources, physical constants) and an extensive reference list. Chapter 1 serves as an introduction, with chapters 2 and 3 dealing with the development of mean and turbulence equations, and the many scaling laws and theories that are the cornerstone of any serious ABL treatment. Modelling of the ABL is crucially dependent for its realism on the surface boundary conditions, and chapters 4 and 5 deal with aerodynamic and energy considerations, with attention to both dry and wet land surfaces and sea. The structure of the clear-sky, thermally stratified ABL is treated in chapter 6, including the convective and stable cases over homogeneous land, the marine ABL and the internal boundary layer at the coastline. Chapter 7 then extends the discussion to the cloudy ABL. This is seen as particularly relevant, since the extensive stratocumulus regions over the subtropical oceans and stratus regions over the Arctic are now identified as key players in the climate system. Finally, chapters 8 and 9 bring much of the book's material together in a discussion of appropriate ABL and surface parameterization schemes in general circulation models of the atmosphere that are being used for climate simulation.
Download or read book Contributions to the Simulation of Turbulence written by John Altnow Dutton and published by . This book was released on 1976 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Digital Techniques in Turbulence Research written by Carl H. Gibson and published by . This book was released on 1973 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rapid advances in electronic information processing capabilities are providing powerful tools for turbulence research. Massive quantities of experimental information are necessary to characterize most turbulent flows, given the primitive nature of theoretical understanding in the field. Analytical treatments are equally dependent on powerful, high speed computers to cope with the most trucated form of the full turbulence problem. Use of digital techniques has great potential for progress in turbulence research but also introduces a new set of difficulties which must be overcome for this potential to be realized.
Download or read book OpenFOAM Large eddy Simulations of Atmospheric Boundary Layer Turbulence for Wind Engineering Applications written by Liang Shi and published by . This book was released on with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Statistical properties such as the spectral density and spatial coherence of boundary layer turbulence affect bluff body aerodynamics and structural responses. In this report, the open-source toolbox OpenFOAM is employed to perform LES simulations of boundary layer flows with rough ground and to obtain turbulence statistics. The one-equation-eddy SGS model is used for the subgrid-scale motions while the wall shear model is applied at the ground. The mean velocity profiles follow the logarithmic law except the near-ground region owing to the limited accuracy of the SGS model. The Reynolds stresses, the third-order moments and the energy budgets are reasonably well represented. The power spectra agree with the modified Kaimal expressions at low frequencies. Additional research is planned on the simulation of higher frequency turbulence spectra. The spatial coherence functions are exponential and consistent with the expressions commonly used in wind engineering applications.
Download or read book Retracted Large eddy Simulation of Turbulent Flows with Applications to Atmospheric Boundary Layer Research written by Hao Lu and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Retracted: Large-eddy simulation of turbulent flows with applications to atmospheric boundary layer research.
Download or read book Dynamic Turbulence Modelling in Large Eddy Simulations of the Cloud Topped Atmospheric Boundary Layer written by M. P. Kirkpatrick and published by . This book was released on 2003 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of large eddy simulation, or LES, to study the atmospheric boundary layer dates back to the early 197Os when Deardorff (1972) used a three-dimensional simulation to determine velocity and temperature scales in the convective boundary layer. In 1974 he applied LES to the problem of mixing layer entrainment (Deardorff 1974) and in 1980 to the cloud-topped boundary layer (Deardorff 1980b). Since that time the LES approach has been applied to atmospheric boundary layer problems by numerous authors.
Download or read book Multiscale Turbulence in the Atmospheric Boundary Layer written by Yu Cheng and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The slope of the proposed temperature log law varies with buoyancy as compared to the universal slope of von K\'arm\'an' velocity log law. The proposed temperature log profile can thus serve as an alternative to Monin-Obukhov similarity theory that is widely applied in climate models and wall models for large eddy simulations. In the last chapter the findings of the dissertation are summarized. Future work on developing new representation of stratified turbulence in numerical weather prediction and climate models and investigating the surface energy imbalance problem in convective conditions are discussed.
Download or read book Subgrid scale Turbulence Modeling for Improved Large eddy Simulation of the Atmospheric Boundary Layer written by Rica Mae Enriquez and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Large-eddy simulation (LES), as the name suggests, resolves the large eddies in the flow while modeling the effects of smaller motions (turbulence) on those larger eddies. Powerful computers make LES increasingly practical for analyzing a variety of atmospheric behavior in more detail, creating a need for more realistic turbulence models. Advances in describing atmospheric turbulence can impact many disciplines, e.g., weather and climate prediction, wind energy production, ocean dynamics, and, indeed, even computational fluid dynamics itself. Although the turbulence model can significantly affect the accuracy of the LES, simple turbulence models, which are known to be less accurate, are widely used. As an alternative, the Generalized Linear Algebraic Subgrid-Scale (GLASS) model, that actively couples momentum and heat transport, was developed. This model is more complete than conventional LES turbulence models because it accounts for additional transport processes. GLASS includes production, dissipation, pressure redistribution, and buoyancy terms. With the inclusion of an actively coupled turbulent heat flux model, GLASS is applicable to a range of atmospheric stability conditions for the unsaturated atmosphere. LES at various resolutions in a neutrally stratified boundary layer flow indicated that the GLASS model is a more physically complete subgrid-scale turbulence model that provides near-wall anisotropies and yields proper velocity profiles in the logarithmic layer. LES of the moderately convective boundary layer demonstrated that GLASS predicted the evolution of resolved quantities at least as well as the LESs with simple models, while including additional physics. Additional simulations of the stable boundary layer and the transitioning boundary layer highlight that GLASS can be applied to various stability conditions without the need of tuning model coefficients.
Download or read book Studying Turbulence Using Numerical Simulation Databases written by Center for Turbulence Research (U.S.) and published by . This book was released on 1987 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement Analysis and Prediction of Atmospheric Boundary Layer Turbulence written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The program objective was to study turbulence in the atmospheric boundary layer and to improve our ability to represent that turbulence through simple models useful in applications. Toward that end we carried out observational studies at our Rock Springs field site and theoretical and computational studies using direct and large eddy simulation. Over the duration of the project we published 22 papers on the topic in scientific journals, have four more under review, made 35 technical presentations at scientific conferences, and supervised the theses of four graduate students. Highlights of the program follow.
Download or read book Modeling Turbulence for Flight Simulations at NASA Ames written by and published by . This book was released on 1975 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
