Final Report on the "New Directions in the Variational Multiscale Formulation of Large Eddy Simulation of Turbulence."

Final Report on the Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The work performed as part of this grant may be described in the context of developing numerical methods for solving an abstract, nonlinear variational problem for which the straightforward Galerkin approximation on a space of reasonable dimension is inaccurate. Target applications include flows with turbulence and systems with shocks. With this in mind, an alternate finite dimensional problem is proposed in which a model term (with unknown parameters) is added to the Galerkin approximation to improve its performance. We have developed new formulations for this model term especially for turbulent flows and for systems with shocks. We have also developed a dynamic approach for evaluating the parameters that appear in this model term. We have conducted several numerical studies to confirm the usefulness of the proposed approach.

Final Report on the "New Directions in the Variational Multiscale Formulation of Large Eddy Simulation of Turbulence."

Final Report on the Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
The work performed as part of this grant may be described in the context of developing numerical methods for solving an abstract, nonlinear variational problem for which the straightforward Galerkin approximation on a space of reasonable dimension is inaccurate. Target applications include flows with turbulence and systems with shocks. With this in mind, an alternate finite dimensional problem is proposed in which a model term (with unknown parameters) is added to the Galerkin approximation to improve its performance. We have developed new formulations for this model term especially for turbulent flows and for systems with shocks. We have also developed a dynamic approach for evaluating the parameters that appear in this model term. We have conducted several numerical studies to confirm the usefulness of the proposed approach.

A Domain Decomposition Based Parallel Implementation of the Variational Multiscale Formulation of Large Eddy Simulation

A Domain Decomposition Based Parallel Implementation of the Variational Multiscale Formulation of Large Eddy Simulation PDF Author: David Alan Carpenter
Publisher:
ISBN:
Category : Decomposition method
Languages : en
Pages : 84

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Book Description


Large Eddy Simulation for Incompressible Flows

Large Eddy Simulation for Incompressible Flows PDF Author: P. Sagaut
Publisher: Springer Science & Business Media
ISBN: 9783540263449
Category : Computers
Languages : en
Pages : 600

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Book Description
First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."

Multiscale and Multiresolution Approaches in Turbulence

Multiscale and Multiresolution Approaches in Turbulence PDF Author: Pierre Sagaut
Publisher: World Scientific
ISBN: 1848169876
Category : Science
Languages : en
Pages : 446

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Book Description
The book aims to provide the reader with an updated general presentation of multiscale/multiresolution approaches in turbulent flow simulations. All modern approaches (LES, hybrid RANS/LES, DES, SAS) are discussed and recast in a global comprehensive framework. Both theoretical features and practical implementation details are addressed. Some full scale applications are described, to provide the reader with relevant guidelines to facilitate a future use of these methods.

Development, Verification and Validation of High-order Methods for the Simulation of Turbulence

Development, Verification and Validation of High-order Methods for the Simulation of Turbulence PDF Author: Farshad Navah
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
"This work discusses the development, the verification and the validation of high-order (of accuracy) solvers for the simulation of turbulent fluid flows. In a first part, a methodology for the verification of high-order solvers is proposed which examines the implementation, in a given computer software, of mathematical models that represent the flow dynamics. The method of manufactured solutions is adopted which allows for the exact evaluation of discretization errors and observed orders of accuracy. The latter are compared to the theoretical orders of accuracy for a variety of increasingly complex problems, starting from unbounded (by walls) inviscid flows and gradually reaching the case of realistic turbulent boundary layers, modelled by the Reynolds-averaged Navier-Stokes equations, along with the original and the negative Spalart-Allmaras closure models. Each case serves to illustrate and discuss salient aspects of the proposed methodology.Code verification via manufactured solutions is furthermore distinguished from solution verification and the latter is extended to high-order frameworks by describing the approach for error estimation via extrapolation of high-order solutions which is applied, as an example, to the case of turbulent flow over a flat plate. This exercise enabled the exploration into the question of high-order grid convergence for various output quantities of interest as well as the question of uncertainty analysis. This pointed at the inadequacy of substituting solution verification to proper high-order solver verification, even for a relatively simple problem and an expert set of grids. It is therefore recommended to use the solutions of actual problems for engineering and science applications, only along with estimated numerical uncertainties, especially for lower orders which are more error-prone. In the second part of this work, a compact high-order variational multiscale method for the large-eddy simulation of turbulence is devised and validated. The existing multiscale method is thus expanded from modal frameworks to a large family of compact high-order nodal schemes, represented by the recent flux reconstruction discretization method. The potential of the proposed formulation is then assessed on a Taylor-Green vortex problem and its results are validated against the filtered data from direct numerical simulations. It is thus revealed that proper de-aliasing is mandatory to conserve the quality of high-order large-eddy simulation. Furthermore, reducing the numerical dissipation of Roe's Riemann solver is found to contribute to improving low-Mach flow solutions for variational multiscale methods. Finally, the proposed variational-multiscale formulation resulted in noticeable improvements over the baseline implicit as well as the classical large-eddy simulations." --

Complex Effects in Large Eddy Simulations

Complex Effects in Large Eddy Simulations PDF Author: Stavros Kassinos
Publisher: Springer Science & Business Media
ISBN: 3540342346
Category : Technology & Engineering
Languages : en
Pages : 440

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Book Description
The field of Large Eddy Simulations is reaching a level of maturity that brings this approach to the mainstream of engineering computations, while it opens opportunities and challenges. The main objective of this volume is to bring together leading experts in presenting the state-of-the-art and emerging approaches for treating complex effects in LES. A common theme throughout is the role of LES in the context of multiscale modeling and simulation.

Large-Eddy Simulations of Turbulence

Large-Eddy Simulations of Turbulence PDF Author: M. Lesieur
Publisher: Cambridge University Press
ISBN: 9780521781244
Category : Mathematics
Languages : en
Pages : 240

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Book Description
Large-Eddy Simulations of Turbulence is a reference for LES, direct numerical simulation and Reynolds-averaged Navier-Stokes simulation.

New Trends in Fluid Mechanics Research

New Trends in Fluid Mechanics Research PDF Author: F. G. Zhuang
Publisher: Springer Science & Business Media
ISBN: 3540759956
Category : Science
Languages : en
Pages : 764

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Book Description
This volume is the proceedings of the Fifth International Conference on Fluid Mechanics (ICFM-V), the primary forum for the presentation of technological advances and research results in the fields of theoretical, experimental, and computational Fluid Mechanics. Topics include: flow instability and turbulence, aerodynamics and gas dynamics, industrial and environmental fluid mechanics, biofluid mechanics, geophysical fluid mechanics, plasma and magneto-hydrodynamics, and others.

Large Eddy Simulation for Incompressible Flows

Large Eddy Simulation for Incompressible Flows PDF Author: Pierre Sagaut
Publisher: Springer Science & Business Media
ISBN: 3662044161
Category : Science
Languages : en
Pages : 326

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Book Description
First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."

Direct and Large-Eddy Simulation XI

Direct and Large-Eddy Simulation XI PDF Author: Maria Vittoria Salvetti
Publisher: Springer
ISBN: 3030049159
Category : Technology & Engineering
Languages : en
Pages : 608

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Book Description
This book gathers the proceedings of the 11th workshop on Direct and Large Eddy Simulation (DLES), which was held in Pisa, Italy in May 2017. The event focused on modern techniques for simulating turbulent flows based on the partial or full resolution of the instantaneous turbulent flow structures, as Direct Numerical Simulation (DNS), Large-Eddy Simulation (LES) or hybrid models based on a combination of LES and RANS approaches. In light of the growing capacities of modern computers, these approaches have been gaining more and more interest over the years and will undoubtedly be developed and applied further. The workshop offered a unique opportunity to establish a state-of-the-art of DNS, LES and related techniques for the computation and modeling of turbulent and transitional flows and to discuss about recent advances and applications. This volume contains most of the contributed papers, which were submitted and further reviewed for publication. They cover advances in computational techniques, SGS modeling, boundary conditions, post-processing and data analysis, and applications in several fields, namely multiphase and reactive flows, convection and heat transfer, compressible flows, aerodynamics of airfoils and wings, bluff-body and separated flows, internal flows and wall turbulence and other complex flows.