Wind Tunnel Studies and Simulations of Turbulent Shear Flows Related to Atmospheric Science and Associated Technologies
Wind Tunnel Studies and Simulations of Turbulent Shear Flows Related to Atmospheric Science and Associated Technologies

Author:

Publisher:

Published: 1969

Total Pages: 39

ISBN-13:

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A summary of accomplishments is given of both an experimental and analytical nature in the following specific studies: (1) Airflow in simulated temperate and tropical forest canopy. (2) Methods of modeling diffusion tests ahead of time to design most efficient and economical field experiments. (3) Use of controlled models of field tests to extend empirical data on CB transport and diffusion. (4) Extend wind tunnel investigation to thermally stratified boundary layers and broader ranges of surface roughness. (5) Investigation of longitudinal dispersion through both shear flow and turbulence. (6) Extend the Lagrangian similarity hypothesis considering a more realistic probability function. (7) Model Dugway Proving Ground and study mean wind patterns near the ground when flow aloft is oriented SW-SE. (Author).

Wind Tunnel Modeling of Plume Rise and Dispersion
Wind Tunnel Modeling of Plume Rise and Dispersion

Author: Gordon Richard Winkel

Publisher:

Published: 1979

Total Pages: 0

ISBN-13:

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Experiments were conducted in a wind tunnel to investigate plume rise and plume growth in neutral atmospheric conditions. The modeling of fullscale plumes in the wind tunnel was studied. The use of plume momentum and the flux of buoyancy as scaling criteria proved successful in modeling plume behaviour. If this criteria is used the stack gas density can be varied between model and fullscale to achieve higher wind tunnel speeds with no effect on plume rise or dispersion. The study shows that careful attention must be given in modeling source conditions such as the stack efflux velocity profile due to its strong influence on plume rise and plume spread. The effects of both initial upward stack gas momentum and buoyant forces on plume rise were combined in a single expression that correlated with plume rise data in the wind tunnel. Plume rise was found to terminate at a downwind distance of 2200 L_ , where L is a buoyancy length scale for a plume, for the simulated atmospheric boundary layer shear flow tested. The effect of wind shear in the approach flow reduced plume rise by about 20% as compared to a uniform flow. The theory of Djurfors and Netterville (1978) closely predicted the reduction in plume rise due to wind shear. The Gaussian dispersion model for an elevated point source correctly characterized plume dispersion in the wind tunnel. Freestream velocity at stack height was chosen as a representative plume convection velocity for the Gaussian model. The plume spread due to buoyancy induced turbulence was measured in the wind tunnel and an expression was found to fit the data. Subsequent measurements showed that the interaction of buoyancy induced turbulence and atmospheric turbulence was nonlinear. An appropriate nonlinear correction was developed and successfully corrected for the initial growth due to buoyancy induced turbulence so that the spread due to atmospheric turbulence was recovered.

Wind Flow and Vapor Cloud Dispersion at Industrial and Urban Sites
Wind Flow and Vapor Cloud Dispersion at Industrial and Urban Sites

Author: Steven R. Hanna

Publisher: John Wiley & Sons

Published: 2010-08-26

Total Pages: 228

ISBN-13: 047093560X

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A key component of risk reduction is reducing the potential consequences that could result from toxic or flammable releases. The science of vapor cloud dispersion has advanced significantly in recent years, but one of the long-standing challenges has been in accounting for dispersion around buildings, equipment, and similarly sized geologic and man-made features. With current concerns about terrorism in industrial and urban sites, improving consequence modeling within industrial and urban sites is more important than ever This new definitive book advances the science of vapor cloud dispersion by: ·Describing how structures at an urban or industrial site affect dispersion, and how these effects should be treated in consequence models ·Explaining surface roughness length (z0) and displacement length (d) so that they are clarified for readers with minimal meteorological background ·Presenting criteria for when the structures should be considered broadly as roughness elements, or when they should be considered from the viewpoint of their wake effects ·Defining conditions for which different models apply and providing continuous solutions for transitions between flow regimes. ·Providing the appropriate roughness inputs to transport and dispersion models depending on conditions. ·Demonstrating the application of these techniques through worked examples.

Turbulent Shear Flows 4
Turbulent Shear Flows 4

Author: L.J.S. Bradbury

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 400

ISBN-13: 3642699960

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The Fourth International Symposium on Turbulent Shear Flows took place at Karlsruhe University in Germany. The papers presented at this Symposium encompassed a similar range to that of the previous meetings, with greater emphasis placed on experimental work, and continued a trend towards the examination of complex flows. Once again, three dimensional, recirculating and reacting flows featured strongly in the programme and were complemented by consideration of two-phase flows and discussions of both numerical and experimental techniques. The Symposium brought together some 300 participants from all over the world, and it was evident that there is a need for Turbulent Shear Flows Symposia, in order to obtain and communicate new information useful to researchers in the field of turbulent flows and of interest to engineers who design flow equipment. This volume contains 27 papers selected from more than 100 presentations at the Symposium which have been reviewed and edited before publication. Together they provide an indication of the status of current knowledge on the subjects represented at the Sympo sium. They are grouped into four sections, namely: • Fundamentals • Free Flows • Boundary Layers • Reacting Flows As in previous volumes in this series, each section begins with an introductory article con sidering the papers which follow in the broader context of available literature and current research.

Turbulent Shear Flows 6
Turbulent Shear Flows 6

Author: Jean-Claude Andre

Publisher: Springer Science & Business Media

Published: 2013-03-09

Total Pages: 455

ISBN-13: 3642739482

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Since the inaugural symposium at the Pennsylvania State University in 1977, the venues for the series of biennial symposia on turbulent shear flows have alternated between the USA and Europe. For the Sixth Symposium, the first to be held in France, the city of Toulouse proved a natura] choice, being a centre for the aerospace industry, meteorological research and higher education. The meeting was hosted by the Paul Sabatier University on the southern perimeter of the city, and there nearly 300 workers in the field of turbulence converged to pronounce upon, debate and absorb the current issues in turbulent shear flows and to enjoy the unfailing September sunshine. The meeting had attracted more than 200 offers of papers from which just over 100 full papers and about 20 shorter communications in open forums could be accommodated. The present volume contains 28 of the original symposium presentations selected by the editors. Each contribution has been revised by its authors - sometimes quite extensively -in the light of the oral presentation. It is our hope that the selection provides a substantial statement of permanent interest on current research in the five areas covered by this book, i.e. fundamentals and closures, scalar transport and geophysical flows, aerodynamic flows, complex flows, and numerical simulations.

Urban Climates
Urban Climates

Author: T. R. Oke

Publisher: Cambridge University Press

Published: 2017-09-14

Total Pages: 549

ISBN-13: 1108179363

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Urban Climates is the first full synthesis of modern scientific and applied research on urban climates. The book begins with an outline of what constitutes an urban ecosystem. It develops a comprehensive terminology for the subject using scale and surface classification as key constructs. It explains the physical principles governing the creation of distinct urban climates, such as airflow around buildings, the heat island, precipitation modification and air pollution, and it then illustrates how this knowledge can be applied to moderate the undesirable consequences of urban development and help create more sustainable and resilient cities. With urban climate science now a fully-fledged field, this timely book fulfills the need to bring together the disparate parts of climate research on cities into a coherent framework. It is an ideal resource for students and researchers in fields such as climatology, urban hydrology, air quality, environmental engineering and urban design.