Spectral Transform Simulations of Turbulent Flows, with Geophysical Applications.

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SeriesCanada Dept. of Fisheries and Oceans Canadian Technical Report of Hydrography and Ocean Sciences -- 57
ContributionsRamsden, D., Whitfield, D., Holloway, G.
ID Numbers
Open LibraryOL21944303M

Spectral Transform Simula­ tions of turbulent flows, with Geophysical Applications. Can. Technical Rep. Hydrogr. and Ocean Sci. Des solutions numeriques des equations des tourbillons baro-tropes et baroclines par la methode des transformees spectrales sont presentees.

Des descriptions des simulations sur ordinateur et des criteres de. G.E. Karniadakis / Spectral element simulations 87 promoters, and finally in Spectral Transform Simulations of Turbulent Flows 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.

Details Spectral Transform Simulations of Turbulent Flows, with Geophysical Applications. FB2

Simulation of Turbulent Flows • From the Navier-Stokes to the RANS equations • Turbulence modeling • k-ε model(s) • Near-wall turbulence modeling important in several applications Flow separation and reattachment are strongly dependent on a correct prediction of the development of turbulence near walls.

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. 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. Large-eddy simulations of geophysical turbulent flows withapplications to planetary boundary layer research May In book: MekIT' 5th national conference on computational mechanics (pp).

Jeremy G. Venditti, Turbulent flow and drag over fixed two‐ and three‐dimensional dunes, Journal of Geophysical Research: Earth Surface, /JF. Book description This is a graduate text on turbulent flows, an important topic in fluid dynamics.

with Geophysical Applications. book It is up-to-date, comprehensive, designed for teaching, and is based on a course taught by the author at Cornell University for a number of years.

The book consists of two parts followed by. 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. Turbulence represents essentially random fluctuations that evolve both spatially and temporally, and appear in various geophysical and space science applications.

A spectral moment method is proposed to characterize the turbulence energy spectra in the wavevector and frequency domain in the lowest-order sense. Various examples of numerically-simulated three-dimensional flows and of coherent vortices imbedded in them are displayed such as three-dimensional isotropic turbulence, free-shear flows, separated flows and boundary-layers.

Comparisons with experimental data are presented and geophysical and industrial applications are discussed. Simulations of geophysical turbulent flows require a robust and accurate subgrid-scale turbulence modeling.

To evaluate turbulence models for stably stratified flows, we performed direct numerical simulations (DNSs) of the transition of the three-dimensional Taylor–Green vortex and of homogeneous stratified turbulence with large-scale horizontal forcing.

SPECTRAL-BASED SIMULATION OF TURBULENCE FIELD (1) General concept o Spectral-based simulation methods has been based on how to decompose the cross spectral matrix: i) Cholesky’s decomposition: based on basis of upper/lower triangle matrices and diagonalized decomposition.

This simulation is the most widely used so far. (English) In: Spectral and High Order Methods for Partial Differential Equations: Selected papers from the ICOSAHOM '09 conference, JuneTrondheim, Norway / [ed] Jan S. Hesthaven; Einar M. Rønquist, Springer,1, p. Chapter in book (Other academic) Abstract [en] Turbulent and transitional channel flow simulations have been performed in order to assess the differences.

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. 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.

Flows in engineering and nature are often characterized by large Reynolds (R e) or Rayleigh (R a) numbers. Examples are the flow of gas in astrophysical disks, atmospheric flows and the cooling of rotating machines. In most cases, it is impossible to resolve all scales of the turbulent flow in a direct numerical simulation (DNS).

Large-eddy simulation of turbulent flow and heat transfer in plane and rib-roughened channels International Journal for Numerical Methods in Fluids, Vol. 15, No. 4 Direct simulations of turbulent flow using finite-difference schemes. Implicit turbulence modeling is the numerical simulation of high Reynolds fluid flow using nonoscillatory finite volume (NFV) schemes without any explicit subgrid scale model.

Here we investigate the ability of a particular NFV scheme, MPDATA, to simulate decaying turbulence in a triply periodic cube for a variety of viscosities, comparing our. where u, B, P and T denote the dimensionless velocity, magnetic field, modified pressure and temperature.e z is the vertical unit vector.

The layer height L has been used as the fundamental length scale and time has been scaled by the thermal diffusion time L 2 /κ, where κ denotes the thermal diffusivity.

Description Spectral Transform Simulations of Turbulent Flows, with Geophysical Applications. FB2

The temperature difference ΔT between the top and the bottom boundary has been. In addition there is a need for generation of the long “ribbons” of turbulent phase that are used to represent the time evolution of the wave front. This makes it unfeasible to use the standard discrete Fourier transform-based technique as a basis for the Monte-Carlo simulation algorithm.

The inverse transform can be used to interpolate f to an alternate set of points [e.g., as demonstrated in Keiner et al. ()]; however, simple application of the inverse transform on neglects the effect of on the spherical harmonic coefficients. The anisotropic characteristics of small-scale forced 2D turbulence on the surface of a rotating sphere are investigated.

In the absence of rotation, the Kolmogorov k −5/3 spectrum is recovered with the Kolmogorov constant C K ≈6, close to previous estimates in plane geometry. Under strong rotation, in long-term simulations without a large-scale drag, a −5 slope emerges in the vicinity.

Turbulent flow generated by the intense rotor–stator interaction is detrimental to the safe running of the centrifugal pump. In order to gain more insight into unsteady velocity pulsation character.

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.

SPECTRAL ANALYSIS OF THE TURBULENT ENERGY SPECTRUM IN SINGLE AND TWO-PHASE BUBBLY FLOWS IN DIFFERENT GEOMETRIES BASED ON DIRECT NUMERICAL SIMULATION RESULTS C.S. Brown, I.A. Bolotnov Department of Nuclear Engineering, North Carolina State University, Stinson Drive, Raleigh, NC, USA [email protected]

The first and most exhaustive work of its kind devoted entirely to the subject, Large Eddy Simulation presents a comprehensive account and a unified view of this young but very rich discipline.

LES is the only efficient technique for approaching high Reynolds numbers when simulating industrial, natural or experimental configurations. The author concentrates on incompressible fluids and chooses /5(3). Originally published inthis book was the first to offer a comprehensive review of large eddy simulations (LES) - the history, state of the art, and promising directions for research.

Among topics covered are fundamentals of LES; LES of incompressible, compressible, and reacting flows; LES of atmospheric, oceanic, and environmental flows; and LES and massivelt parallel computing. The.

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Direct and large eddy simulations of engineering and geophysical turbulent flows We investigate, develop, and use numerical techniques of Computational Fluid Dynamics to study turbulence in gases and fluids.

Highly accurate spectral and spectral element numerical methods are employed. I Application of the Statistical Theory to Stratified and Rotating Turbulence.- Computational Challenges for Global Dynamics of Fully Developed Turbulence in the Context of Geophysical Flows.- Structural and Statistical Aspects of Stably Stratified Turbulence.- Dynamics of Rotating Stably Stratified Flows.

() Mathematical analysis of a spectral hyperviscosity LES model for the simulation of turbulent flows. ESAIM: Mathematical Modelling and Numerical Analysis() A deconvolution-based fourth-order finite volume method for incompressible flows on non-uniform grids.Filtering Techniques for Turbulent Flow Simulation Alvaro A.

Aldama (auth.) 1. 1 Scope of the Study The detailed and reasonably accurate computation of large scale turbulent flows has become increasingly important in geophysical and engi­ neering applications in recent years.This is the 4th edition of a book originally published by Kluwer Academic Publishers.

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 s: 2.