Download or read book Large eddy Simulation of the Evolving Stable Boundary Layer Over Flat Terrain written by Richard Townsend Cederwall and published by . This book was released on 2001 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Eddy Simulation of the Evolving Stable Boundary Layer Over Flat Terrain written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The stable boundary layer (SBL) in the atmosphere is of considerable interest because it is often the worse case scenario for air pollution studies and health effect assessments associated with the accidental release of toxic material. Traditional modeling approaches used in such studies do not simulate the non-steady character of the velocity field, and hence often overpredict concentrations while underpredicting spatial coverage of potentially harmful concentrations of airborne material. The challenge for LES is to be able to resolve the rather small energy-containing eddies of the SBL while still maintaining an adequate domain size. This requires that the subgrid-scale (SGS) parameterization of turbulence incorporate an adequate representation of turbulent energy transfer. Recent studies have shown that both upscale and downscale energy transfer can occur simultaneously, but that overall the net transfer is downscale. Including the upscale transfer of turbulent energy (energy backscatter) is particularly important near the ground and under stably-stratified conditions. The goal of this research is to improve the ability to realistically simulate the SBL. The large-eddy simulation (LES) approach with its subgrid-scale (SGS) turbulence model does a better job of capturing the temporally and spatially varying features of the SBL than do Reynolds-averaging models. The scientific objectives of this research are: (1) to characterize features of the evolving SBL structure for a range of meteorological conditions (wind speed and surface cooling), (2) to simulate realistically the transfer of energy between resolved and subgrid scales, and (3) to apply results to improve simulation of dispersion in the SBL.
Download or read book Large eddy Simulation of the Stable Boundary Layer and Implications for Transport and Dispersion written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Large-eddy simulation (LES) of the evolving stable boundary layer (SBL) provides unique data sets for assessing the effects of stable stratification on transport and dispersion. The simulations include the initial development of the convective boundary layer (CBL) in the afternoon, followed by the development of an SBL after sunset with a strong, surface-based temperature inversion. The structure of the turbulence is modified significantly by negative buoyancy associated with the temperature inversion. The magnitude of velocity variances is reduced by an order of magnitude compared to that in the CBL, and the vertical velocity variance is damped further as the static stability preferentially damps vertical motions. The advanced subgrid-scale turbulence model allows simulation of intermittently enhanced periods of turbulence in the SBL that am often observed. During these turbulent episodes, mixing is increased within the SBL. Air pollution models that account only for the long-term mean structure of the SBL do not include the effects of these episodes. In contrast, our LES results imply that material released near the surface and mixed to higher elevations would be transported by stronger winds and in different directions, due to the vertical shear of horizontal wind speed and direction. Material released at altitude in the SBL will tend to be mixed downward toward the surface during these turbulent episodes in a fumigation-like scenario at night.
Download or read book Large eddy Simulation of the Development of Stably stratified Atmospheric Boundary Layers Over Cool Flat Surfaces written by and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The stable boundary layer (SBL) has received less attention in atmospheric field studies, laboratory experiments, and numerical modeling than other states of the atmospheric boundary layer. The low intensity and potential intermittency of turbulence in the SBL make it difficult to measure and characterize its structure. Large-eddy simulation (LES) offers an approach for simulating the SBL and, in particular, its evolution from the onset of surface cooling. Traditional approaches that involve Reynolds-averaged models of turbulence are not able to simulate the stochastic nature of the intermittent turbulence that is associated with the SBL. LES shows promise in this area through its explicit calculation of turbulent eddies at resolved scales. In the LES approach, the Navier-Stokes equations governing the flow are averaged (filtered) over some small interval, such as one or more cells of the computational grid. The grid size is small enough so that large eddies, which carry most of the turbulent energy, are explicitly calculated. The turbulence associated with the subgrid-scale (SGS) eddies is modeled. In the Reynolds-averaging approach, on the other hand, the turbulence model must account for all scales of turbulence. Thus the advantage of LES is that the choice of turbulence parameterization for the SGS turbulence is not nearly as critical as in the Reynolds-averaged approach. Complications faced by turbulence models, such as anisotropy and pressure-strain correlations, are associated mainly with large, energy-containing eddies. LES offers the potential for more realistic simulations since the more complicated features of turbulence are calculated explicitly. The ability of LES to simulate the stochastic behavior of turbulence makes this approach suitable for developing and testing stochastic models of turbulent diffusion. One of the goals of the present work is to provide stochastic datasets to be used in such studies.
Download or read book Large Eddy Simulation of Stable Boundary Layer Turbulent Processes in Complex Terrain written by Eric D. Skyllingstad and published by . This book was released on 2005 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research was performed using a turbulence boundary layer model to study the behavior of cold, dense flows in regions of complex terrain. Results show that flows develop a balance between turbulent entrainment of warm ambient air and dense, cold air created by surface cooling. Flow depth and strength is a function of downslope distance, slope angle and angle changes, and the ambient air temperature.
Download or read book Large Eddy Simulation for Incompressible Flows written by P. Sagaut and published by Springer Science & Business Media. This book was released on 2006 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."
Download or read book Wind Energy Related Atmospheric Boundary Layer Large Eddy Simulation Using OpenFOAM written by and published by . This book was released on 2010 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper develops and evaluates the performance of a large-eddy simulation (LES) solver in computing the atmospheric boundary layer (ABL) over flat terrain under a variety of stability conditions, ranging from shear driven (neutral stratification) to moderately convective (unstable stratification).
Download or read book Large eddy Simulation of a Spatially Evolving Compressible Boundary Layer Flow written by Evangelos T. Spyropoulos and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mountain Weather Research and Forecasting written by Fotini K. Chow and published by Springer Science & Business Media. This book was released on 2012-08-30 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with a broad understanding of the fundamental principles driving atmospheric flow over complex terrain and provides historical context for recent developments and future direction for researchers and forecasters. The topics in this book are expanded from those presented at the Mountain Weather Workshop, which took place in Whistler, British Columbia, Canada, August 5-8, 2008. The inspiration for the workshop came from the American Meteorological Society (AMS) Mountain Meteorology Committee and was designed to bridge the gap between the research and forecasting communities by providing a forum for extended discussion and joint education. For academic researchers, this book provides some insight into issues important to the forecasting community. For the forecasting community, this book provides training on fundamentals of atmospheric processes over mountainous regions, which are notoriously difficult to predict. The book also helps to provide a better understanding of current research and forecast challenges, including the latest contributions and advancements to the field. The book begins with an overview of mountain weather and forecasting chal- lenges specific to complex terrain, followed by chapters that focus on diurnal mountain/valley flows that develop under calm conditions and dynamically-driven winds under strong forcing. The focus then shifts to other phenomena specific to mountain regions: Alpine foehn, boundary layer and air quality issues, orographic precipitation processes, and microphysics parameterizations. Having covered the major physical processes, the book shifts to observation and modelling techniques used in mountain regions, including model configuration and parameterizations such as turbulence, and model applications in operational forecasting. The book concludes with a discussion of the current state of research and forecasting in complex terrain, including a vision of how to bridge the gap in the future.
Download or read book Large eddy Simulation of Turbulent Boundary Layer Over Sinusoidal Hills and Multiscale Complex Topography written by Feng Wan and published by . This book was released on 2011 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High resolution Large eddy Simulation Studies of the Turbulent Structure of the Convective Boundary Layer Over Homogeneous and Heterogeneous Terrain and Implications for the Interpretation of Scintillometer Data written by Björn Maronga and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Large eddy Simulation of Transitional Wall bounded Flows written by Ugo Piomelli and published by . This book was released on 1989 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Workshop on Diurnal Cycles and the Stable Boundary Layer written by and published by . This book was released on 2012 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Shear Flows 8 written by Franz Durst and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains a selection of the papers presented at the Eighth Symposium on Turbulent Shear Flows held at the Technical University of Munich, 9-11 September 1991. The first of these biennial international symposia was held at the Pennsylvania State Uni versity, USA, in 1977; subsequent symposia have been held at Imperial College, London, England; the University of California, Davis, USA; the University of Karlsruhe, Ger many; Cornell University, Ithaca, USA; the Paul Sabatier University, Toulouse, France; and Stanford University, California, USA. The purpose of this series of symposia is to provide a forum for the presentation and discussion of new developments in the field of turbulence, especially as related to shear flows of importance in engineering and geo physics. From the 330 extended abstracts submitted for this symposium, 145 papers were presented orally and 60 as posters. Out of these, we have selected twenty-four papers for inclusion in this volume, each of which has been revised and extended in accordance with the editors' recommendations. The following four theme areas were selected after consideration of the quality of the contributions, the importance of the area, and the selection made in earlier volumes: - wall flows, - separated flows, - compressibility effects, - buoyancy, rotation, and curvature effects. As in the past, each section corresponding to the above areas begins with an introduction by an authority in the field that places the individual contributions in context with one another and with related research.
Download or read book Mesoscale Meteorology and Forecasting written by Peter Ray and published by Springer. This book was released on 2015-03-30 with total page 803 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of selected lectures presented at the ‘Intensive Course on Mesoscale Meteorology and Forecasting’ in Boulder, USA, in 1984. It includes mesoscale classifications, observing techniques and systems, internally generated circulations, mesoscale convective systems, externally forced circulations, modeling and short-range forecasting techniques. This is a highly illustrated book and comprehensive work, including extensive bibliographic references. It is aimed at graduates in meteorology and for professionals working in the field.
Download or read book An Introduction to Boundary Layer Meteorology written by Roland B. Stull and published by Springer Science & Business Media. This book was released on 1988-07-31 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: Part of the excitement in boundary-layer meteorology is the challenge associated with turbulent flow - one of the unsolved problems in classical physics. An additional attraction of the filed is the rich diversity of topics and research methods that are collected under the umbrella-term of boundary-layer meteorology. The flavor of the challenges and the excitement associated with the study of the atmospheric boundary layer are captured in this textbook. Fundamental concepts and mathematics are presented prior to their use, physical interpretations of the terms in equations are given, sample data are shown, examples are solved, and exercises are included. The work should also be considered as a major reference and as a review of the literature, since it includes tables of parameterizatlons, procedures, filed experiments, useful constants, and graphs of various phenomena under a variety of conditions. It is assumed that the work will be used at the beginning graduate level for students with an undergraduate background in meteorology, but the author envisions, and has catered for, a heterogeneity in the background and experience of his readers.
Download or read book Large eddy Simulation of Stably Stratified Atmospheric Boundary Layer Turbulence written by Sukanta Basu and published by . This book was released on 2004 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
