A Study on Homogeneous Sheared Stably Stratified Turbulence PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download A Study on Homogeneous Sheared Stably Stratified Turbulence PDF full book. Access full book title A Study on Homogeneous Sheared Stably Stratified Turbulence by Gavin Portwood. Download full books in PDF and EPUB format.
Author: Gavin Portwood Publisher: ISBN: Category : Languages : en Pages :
Book Description
Homogeneous sheared and stably stratified turbulence is considered as a fundamental flow relevant to the study of geophysical turbulence and, generally, anisotropic turbulence. Numerical experiments are performed via high resolution direct numerical simulation (DNS) in a geophysically-relevant parameter space previously inaccessible to simulation. Turbulent dynamics relevant to the modeling of geophysical hydrodynamics are investigated as a function of mean flow and fluid parameters. An active tuning scheme is implemented to induce temporally stationary turbulent kinetic energy in order to evaluate turbulence that is statistically independent of initial conditions and spatio-temporally homogeneous. Subject to this constraint, the parametric dependence of the flow reduces to a single Reynolds number, here defined as the shear Reynolds number Res ≡ (LC∕LK)4∕3 (Itweire et al. 1993, Corrsin 1958), where L C is the smallest turbulent anisotropic scale in the flow and LK represents the smallest scales of turbulence associated with viscosity, which parameterizes the range of length scales that are associated with isotropy for stationary flow configurations. By varying Res independently from other parameters, commonly suggested empirical scalings of the rate of mixing are shown to not hold. The turbulence and scalar dynamics approach an asymptotic state for Res ≿ 300, as evidenced by small-scale isotropy, an asymptotic partitioning of available potential energy to kinetic energy and two-point scaling. In light of this asymptotic state, an alternative parameterization is suggested, from robust classical scaling arguments, with dependence only on classical universal constants and mean energetics in the high Res limit. In an effort to simplify the conceptual description of geophysical turbulence, we suggest a unified length-scale framework based on the work of Gargett et al. 1984. Based on this framework, a parameterization for the isotropic length scale regime is suggested for generic (non-stationarity) flow configurations, which is evaluated with a series of decaying simulations.
Author: Gavin Portwood Publisher: ISBN: Category : Languages : en Pages :
Book Description
Homogeneous sheared and stably stratified turbulence is considered as a fundamental flow relevant to the study of geophysical turbulence and, generally, anisotropic turbulence. Numerical experiments are performed via high resolution direct numerical simulation (DNS) in a geophysically-relevant parameter space previously inaccessible to simulation. Turbulent dynamics relevant to the modeling of geophysical hydrodynamics are investigated as a function of mean flow and fluid parameters. An active tuning scheme is implemented to induce temporally stationary turbulent kinetic energy in order to evaluate turbulence that is statistically independent of initial conditions and spatio-temporally homogeneous. Subject to this constraint, the parametric dependence of the flow reduces to a single Reynolds number, here defined as the shear Reynolds number Res ≡ (LC∕LK)4∕3 (Itweire et al. 1993, Corrsin 1958), where L C is the smallest turbulent anisotropic scale in the flow and LK represents the smallest scales of turbulence associated with viscosity, which parameterizes the range of length scales that are associated with isotropy for stationary flow configurations. By varying Res independently from other parameters, commonly suggested empirical scalings of the rate of mixing are shown to not hold. The turbulence and scalar dynamics approach an asymptotic state for Res ≿ 300, as evidenced by small-scale isotropy, an asymptotic partitioning of available potential energy to kinetic energy and two-point scaling. In light of this asymptotic state, an alternative parameterization is suggested, from robust classical scaling arguments, with dependence only on classical universal constants and mean energetics in the high Res limit. In an effort to simplify the conceptual description of geophysical turbulence, we suggest a unified length-scale framework based on the work of Gargett et al. 1984. Based on this framework, a parameterization for the isotropic length scale regime is suggested for generic (non-stationarity) flow configurations, which is evaluated with a series of decaying simulations.
Author: P. A. Davidson Publisher: Cambridge University Press ISBN: 1107434343 Category : Science Languages : en Pages : 701
Book Description
There are two recurring themes in astrophysical and geophysical fluid mechanics: waves and turbulence. This book investigates how turbulence responds to rotation, stratification or magnetic fields, identifying common themes, where they exist, as well as the essential differences which inevitably arise between different classes of flow. The discussion is developed from first principles, making the book suitable for graduate students as well as professional researchers. The author focuses first on the fundamentals and then progresses to such topics as the atmospheric boundary layer, turbulence in the upper atmosphere, turbulence in the core of the earth, zonal winds in the giant planets, turbulence within the interior of the sun, the solar wind, and turbulent flows in accretion discs. The book will appeal to engineers, geophysicists, astrophysicists and applied mathematicians who are interested in naturally occurring turbulent flows.
Author: NA Schumann Publisher: Springer Science & Business Media ISBN: 3663001970 Category : Technology & Engineering Languages : en Pages : 350
Book Description
This volume contains papers presented to a EUROMECH-Colloquium held in Munich, September 30 to October 2, 1985. The Colloquium is number 199 in a series of colloquia inaugurated by the European Mechanics Committee. The meeting was jointly organized by the 'Lehrstuhl fur Stromungsmechanik' at the 'Technische Universitat Munchen' and the 'Institut fur Physik der Atmosphare' of the 'Deutsche Forschungs- und Versuchsanstalt fur Luft- und Raumfahrt' (DFVLR) in Oberpfaffenhofen. 'Direct' and 'large eddy simulation' are terms which denote two closely con nected methods of turbulence research. In a 'direct simulation' (DS), turbu lent motion is simulated by numerically integrating the Navier-Stokes equations in three-dimensional space and as a function of time. Besides ini tial and boundary conditions no physical simplifications are involved. Com puter resources limit the resolution in time and space, though simulations with an order of one million discrete points in space are feasible. The simu lated flow fields can be considered as true realizations of turbulent flow fields and analysed to answer questions on the basic behaviour of turbulence. Direct simulations are valid as long as all the excited scales remain within the band of resolved scales. This means that viscosity must be strong enough to damp out the not resolved scales or the simulation is restricted to a lim ited integration-time interval only. In summary, DS provides a tool to investigate turbulent motions from first principles at least for a finite band of scales.
Author: Vincenzo Armenio Publisher: Springer Science & Business Media ISBN: 3211380787 Category : Science Languages : en Pages : 238
Book Description
This book covers the theory of stratified flows, from basic concepts to recent developments in environmental fluid mechanics. State-of-the-art numerical techniques suited for stratified flows are given, along with results of recent research in the areas of environmental stratified flows. The book offers a unified view of stratified turbulent flows, from small-scale mixing to large-scale environmental phenomena, including detailed discussion on interaction between turbulence and internal gravity waves.
Author: Maurizio Brocchini Publisher: WIT Press ISBN: 1845640527 Category : Science Languages : en Pages : 305
Book Description
This book contains a collection of 11 research and review papers which have been contributed by each research unit joining the MIUR funded project: "Influence of vorticity and turbulence in interactions of water bodies with their boundary elements and effects on hydraulic design". The book features state-of-the-art Italian research devoted to the topic of fluid-structure interaction.
Author: Gavin Portwood
Author: Gavin Portwood
Author: Steven E. Holt
Author: P. A. Davidson
Author: A. A. R. Townsend
Author: S. T. B. Young
Author: NA Schumann
Author: Paul Piccirillo
Author: Vincenzo Armenio
Author: 
Author: Maurizio Brocchini