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3 edition of Spectral transform simulations of turbulent flows, with geophysical applications found in the catalog.

Spectral transform simulations of turbulent flows, with geophysical applications

D. Ramsden

Spectral transform simulations of turbulent flows, with geophysical applications

by D. Ramsden

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  • 14 Currently reading

Published by Fisheries and Oceans Canada in Sidney, B.C .
Written in English


Edition Notes

Statementby D. Ramsden, D. Whitfield, and G. Holloway.
SeriesCanadian technical report of hydrography and ocean sciences -- no. 57
ContributionsWhitfield, D., Holloway, G., Canada. Dept. of Fisheries and Oceans., Institute of Ocean Sciences, Patricia Bay.
The Physical Object
FormatMicroform
Pagination1 microfiche.
ID Numbers
Open LibraryOL19796539M

LES is one of the most successful techniques for the numerical simulation of turbulent flows. Introduced more than 30 years ago for geophysical applications, LES has been developed mainly in the engineering community. LES aims at approximating the large structures (eddies) in the turbulent flow. In all simulations a stationary state is reached in which there is a constant spectral energy flux and equipartition between kinetic and potential energy in the constant flux range. The third-order structure function relation is satisfied with a high degree of accuracy.

A spectral element—Fourier method (SEM) for Direct Numerical Simulation (DNS) of the turbulent flow of non-Newtonian fluids is described and the particular requirements for non-Newtonian.   Turbulence, a scientific term to describe certain complex and unpredictable motions of a fluid, is part of our daily experience and has been for a long telescope or microscope is needed to contemplate the volutes of smoke from a cigarette, the elegant arabesques of cream poured into coffee and the vigorous eddies of a mountain stream.

Numerical simulations of turbulent open channel flows have been carried out for two Reynolds numbers, Re b = , corresponding to Re τ = L y u τ /ν = and , where u τ = (τ w /ρ) 1/2 is the friction velocity and τ w is the shear stress at the wall. LES.2 Large Eddy Simulation Model for Turbulent Flow integral length scale from two-point, one-time autocovariance, = 1 = ˆ Homogeneous turbulence, pseudo-spectral resolution requirements max smallest scale of motion is Kolmo grov scale η adequate resolution: κη /η = π/ 2.


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Spectral transform simulations of turbulent flows, with geophysical applications by D. Ramsden Download PDF EPUB FB2

Spectral TransformSimula­ turbulent flows, with Geophysical Applications. Can. Technical Rep. and Ocean Sci. Numerical solutions of barotropic and baroclinic vorticity equations by the method of spectral transforms are presented.

Descriptions of the computet simulations, along with criteria for parameterisation of oceanographic and. Get this from a library. Spectral transform simulations of turbulent flows, with geophysical applications.

[D Ramsden; D Whitfield; G Holloway; Canada. Department of Fisheries and Oceans.; Institute of Ocean Sciences, Patricia Bay.] -- Numerical solutions of barotropic and baroclinic vorticityequations by the method of spectral transforms are presented.

Direct Numerical Simulation of Turbulent Flows Using Spectral Methods K. Sengupta,⁄ and F. Mashayeky University of Illinois at Chicago G. Jacobs,z San Diego State University Direct numerical simulation (DNS) is the most accurate method of solving turbulence in °uids.

In DNS the Navier-Stokes equations are solved on a flne mesh to resolve all. Contour maps of turbulent flow parameters demonstrate that the flow separation cell and a perturbed shear layer are the main sources of turbulence production and that the distribution of suspended sediment is controlled by spatially dependent macro turbulent flow structures.

Spectral analysis reveals that peak spectral energies generally occur Cited by: Large-eddy simulations of geophysical turbulent flows withapplications to planetary boundary layer research May In book: MekIT' 5th national conference on computational mechanics (pp).

We propose a new kind of compact difference scheme for the computation of the first and second derivatives in the simulation of high-Reynolds number turbulent flows. The scheme combines and truncates the pseudospectral representation of derivative for convergence acceleration.

Numerical simulation of turbulent flow is of practical importance in geophysics and is useful as a test of turbulence theory. From a basic scale analysis of turbulent flow it is shown that complete simulation is only practicable for two‐dimensional or marginally turbulent three‐dimensional flows.

Some examples of such simulations are described. G.E. Karniadakis / Spectral element simulations 87 promoters, and finally in Section we present the results of a direct simulation of the turbulent flow in a plane channel.

Mathematical formulation We consider here Newtonian, incompressible flows with constant properties, which are.

Cautionary remarks on the spectral interpretation of turbulent flows. Laurence Armi. Search for more papers by this author They are primarily a consequence of applying spectral analysis to flows that are not wavelike but contain simple structures represented by a broad extension in wave number space.

Journal of Geophysical Research. Hadri, and R. Khurram. Scaling of a Fast Fourier Transform and a pseudo-spectral fluid solver up to cores.

Parallel and Distrib. Comput. (), Google Scholar Cross Ref; M. Clay, D. Buaria, P. Yeung, and T. Gotoh. GPU acceleration of a petascale application for turbulent mixing at high Schmidt number.

A finite volume dynamic large-eddy simulation method for buoyancy driven turbulent geophysical flows Article (PDF Available) in Ocean Modelling 17(3) December with Reads. The second part of the chapter is more geophysical and reproduces with permission granted by Cambridge University Press the chapter on “Geophysical fluid dynamics” from the book Large-eddy simulations of turbulence by Lesieur, Métais and Comte [].

We first make a survey of flows encountered in Geophysics, with relevant climatic issues. The book consists of two parts followed by a number of appendices.

Part I provides a general introduction to turbulent flows, how they behave, how they can be described quantitatively, and the fundamental physical processes involved. Part II is concerned with different approaches for modelling or simulating turbulent flows.

Peer-review under responsibility of Indian Institute of Technology, Hyderabad. doi: / ScienceDirect IUTAM Symposium on Multiphase flows with phase change: challenges and opportunities, Hyderabad, India (December 08 – Decem ) Turbulent Transport Processes at Rough Surfaces with Geophysical.

It is an exhaustive monograph on turbulence in fluids in its theoretical and applied aspects, with many advanced developments using mathematical spectral methods (two-point closures like the EDQNM theory), direct-numerical simulations, and large-eddy simulations.

The book is still of great actuality on a topic of the utmost importance for engineering and environmental applications, and presents a very Reviews: 2. We develop a coupled hydro-morphodynamic numerical model for carrying out large-eddy simulation of stratified, turbulent flow over a mobile sand bed.

The method is based on the curvilinear immersed boundary approach of Khosronejad et al. (Adv. Water Resour., vol. 34,pp. Abstract. Numerical simulations of two-dimensional turbulent flows exhibit strong solitary, long-lived, coherent vortices ; these coherent structures are not taken in account in the à la Kolmogorov similarity theory, this brings to a difference between the theoretical predictions of spectral slopes and those coming from numerical experiments.

How do these coherent structures contribute to the. The hexagonal Fourier transform can be easily implemented by using fast Fourier transform (FFT) libraries, and is expected to be applied in future pseudo-spectral methods of two-dimensional and quasi-three-dimensional turbulent flows to minimize the background anisotropy.

Direct Numerical Simulations (DNS) is a term reserved for computer simulations of turbulent flows that are fully resolved in both time and space.

DNS are usually conducted using numerical methods of such high order and accuracy that numerical dispersion and diffusion errors are negligible compared to their actual physical counterparts.

We then propose a new method, called coherent vortex simulation (CVS), designed to compute and model two-dimensional turbulent flows using the previous wavelet decomposition at each time step. Numerical simulations of turbulent flows can be performed to capture (1) the temporal fluctuations and (2) the time-averaged features in the flow field.

For example, let us consider a simulated flow through an asymmetric diffuser.Simulation of turbulent flows with the entropic multirelaxation time lattice Boltzmann D.K. On the computational stability of numerical solutions of time-dependent non-linear geophysical fluid dynamics S.

A. Transform method for the calculation of vector-coupled sums: application to the spectral form of the vorticity.Basic theory is presented next, illustrated by examples of simple turbulent flows and developed through classical models of jets, wakes, and boundary layers.

A deeper understanding of turbulence dynamics is provided by spectral analysis and its applications. The final chapter introduces the numerical simulation of turbulent flows.