[PDF] Stably Stratified Flows Flow And Dispersion Over Topography eBook

Author : I. P. Castro
Publisher : Oxford University Press, USA
Page : 384 pages
File Size : 43,68 MB
Release : 1994
Category : Mathematics
ISBN :

GET BOOK

The first papers of this conference addressed the long-standing issues of the nature of the upstream effects that occur in stratified flow over obstacles (P G Baines, CSIRO, Australia, A P Taylor, York University, Ontario, Canada; K W Ayotte, Boulder, Colorado, USA). Then followed a sessionon internal wave motions followed by a session on modelling the atmospheric boundary layer (J C King, British Antarctic Survey, Cambridge; A Kay, Loughborogh University of Technology). There was a session on numerical modelling (O Matais, Instite de Mecanique de Grenoble, France; A S Smedman,Uppsala University). The various aspects of dispersion were discussed and the final papers in the conference described laboratory experiments on flow and dispersion around buildings in light wind conditions.

Author : Roger Grimshaw
Publisher : Springer Science & Business Media
Page : 286 pages
File Size : 29,65 MB
Release : 2006-04-11
Category : Science
ISBN : 0306480247

GET BOOK

The dynamics of flows in density-stratified fluids has been and remains now an important topic for scientific enquiry. Such flows arise in many contexts, ranging from industrial settings to the oceanic and atmospheric environments. It is the latter topic which is the focus of this book. Both the ocean and atmosphere are characterised by the basic vertical density stratification, and this feature can affect the dynamics on all scales ranging from the micro-scale to the planetary scale. The aim of this book is to provide a “state-of-the-art” account of stratified flows as they are relevant to the ocean and atmosphere with a primary focus on meso-scale phenomena; that is, on phenomena whose time and space scales are such that the density stratification is a dominant effect, so that frictional and diffusive effects on the one hand and the effects of the earth’s rotation on the other hand can be regarded as of less importance. This in turn leads to an emphasis on internal waves.

Author : P. A. Davies
Publisher : Oxford University Press
Page : 668 pages
File Size : 49,18 MB
Release : 1999
Category : Diffusion in hydrology
ISBN : 9780198500155

GET BOOK

Stratified flows are important in determining how various atmospheric and environmental processes occur. The book investigates these processes and focuses on the methods by which pollutants are mixed and dispersed in natural and industrial environments.

Author : Peter G. Baines
Publisher : Cambridge University Press
Page : 559 pages
File Size : 50,56 MB
Release : 2022-01-27
Category : Science
ISBN : 1108481523

GET BOOK

Explore the nature of density-stratified flow over and around topography, including applications to the flow of the atmosphere and ocean.

Author :
Publisher :
Page : pages
File Size : 45,98 MB
Release : 2004
Category :
ISBN :

GET BOOK

O objetivo principal do presente trabalho foi investigar computacionalmente o escoamento e a dispersão de poluentes atmosféricos sobre topografias complexas tridimensionais em escala de laboratório. Foram realizadas simulações numéricas de escoamentos neutros e estavelmente estratificados sobre colinas e também sobre terreno plano. A modelagem matemática, baseada na solução das equações gerais de conservação, inclui o modelo de tensões de Reynolds para a turbulência e um modelo de duas camadas para o tratamento do escoamento na região próxima à parede. O código comercial Fluent (Versão 6.0.12), que emprega o método de volumes finitos, foi utilizado nas simulações computacionais. Os resultados numéricos foram comparados a dados obtidos em experimentos em túnel de vento disponíveis na literatura. Também foram realizadas comparações com resultados obtidos com a utilização do modelo (k menos épsilon) clássico. A comparação entre os resultados obtidos com as diversas modelagens numéricas e os dados experimentais mostrou que a utilização conjunta do modelo de tensões de Reynolds e do tratamento em duas camadas produziu os melhores resultados na predição do escoamento. O desempenho dessa modelagem foi particularmente superior na representação da recirculação no escoamento na região a jusante da colina. Com relação ao cálculo das concentrações, os resultados obtidos foram razoáveis nas regiões mais distantes da fonte quando comparados aos experimentais. Na região mais próxima à fonte emissora, foram calculadas concentrações excessivamente altas ao nível do solo. Estas discrepâncias foram atribuídas ao fato de ter-se utilizado um modelo de difusividade turbulenta isotrópica para os cálculos da dispersão turbulenta do poluente. Ainda assim, os campos de concentrações apresentados mostraram importantes aspectos qualitativos relativos ao problema como, por exemplo, os efeitos da estabilidade atmosférica na dispersão do poluente, que foram adequadamente previstos.

Author : Nancy Soontiens
Publisher :
Page : 193 pages
File Size : 10,42 MB
Release : 2013
Category :
ISBN :

GET BOOK

This thesis investigates several aspects of stratified flow over isolated topography in ocean, lake, and atmospheric settings. Three major sub-topics are addressed: steady, inviscid internal waves trapped over topography in a pycnocline stratification, topographically generated internal waves and their interaction with the viscous bottom boundary layer, and flow over large-scale crater topography in the atmosphere. The first topic examines the conditions that lead to very large internal waves trapped over topography in a fluid with a pycnocline stratification. This type of stratification is connected to ocean or lake settings. The steady-state Euler equations of motion are used to derive a single partial differential equation for the isopycnal displacement in supercritical flows under two conditions: a vertically varying background current under the Boussinesq approximation and a constant background current under non-Boussinesq conditions. A numerical method is developed to solve these equations for an efficient exploration of parameter space. Very large waves are found over depression topography when the background flow speed is close to a limiting value. Variations in the background current are examined, as well as comparisons between Boussinesq and non-Boussinesq results. The second topic aims to extend the above subject by considering unsteady, viscous flows. Once again, supercritical flow over topography in a pycnocline stratification generates internal waves. These internal waves interact with the viscous bottom boundary layer to produce bottom boundary instabilities. The three-dimensional aspects of these instabilities are studied under changes in viscosity. The boundary layer instabilities have important implications for sediment transport in the coastal oceans or lakes. Lastly, the final topic is motivated by the connection between dust streaks on the Martian surface and crater topography. Flow over a large 100-km diameter crater is examined with numerical simulations conducted using the Weather Research and Forecasting model. Modifications to the stratification and topography are applied. It is found that a large hydraulic structure of amplitude comparable to the crater depth forms in many cases. This structure may have important implications for dust transport in the atmosphere. In addition, Martian atmospheric parameters are used to study the flow properties under Mars-like conditions.

Author : Jaroslav Fořt
Publisher : Springer Science & Business Media
Page : 1003 pages
File Size : 45,90 MB
Release : 2011-07-21
Category : Mathematics
ISBN : 3642206719

GET BOOK

Finite volume methods are used for various applications in fluid dynamics, magnetohydrodynamics, structural analysis or nuclear physics. A closer look reveals many interesting phenomena and mathematical or numerical difficulties, such as true error analysis and adaptivity, modelling of multi-phase phenomena or fitting problems, stiff terms in convection/diffusion equations and sources. To overcome existing problems and to find solution methods for future applications requires many efforts and always new developments. The goal of The International Symposium on Finite Volumes for Complex Applications VI is to bring together mathematicians, physicists and engineers dealing with Finite Volume Techniques in a wide context. This book, divided in two volumes, brings a critical look at the subject (new ideas, limits or drawbacks of methods, theoretical as well as applied topics).