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Improved Turbulence Models Based On Large Eddy Simulation Of Homogeneous Incompressible Turbulent Flows
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Book Synopsis Improved Turbulence Models Based on Large Eddy Simulation of Homogeneous, Incompressible, Turbulent Flows by : Stanford University. Thermosciences Division. Thermosciences Division
Download or read book Improved Turbulence Models Based on Large Eddy Simulation of Homogeneous, Incompressible, Turbulent Flows written by Stanford University. Thermosciences Division. Thermosciences Division and published by . This book was released on 1983 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The physical bases of large eddy simulation and the subgrid scale modeling it employs are studied in some detail. This investigation leads to a new scale-similarity model for the subgrid-scale turbulent Reynolds stresses.
Book Synopsis Turbulent Shear Flows I by : F. Durst
Download or read book Turbulent Shear Flows I written by F. Durst and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present book contains papers that have been selected from contributions to the First International Symposium on Turbulent Shear Flows which was held from the 18th to 20th April 1977 at The Pennsylvania State University, University Park, Pennsylvania, USA. Attend ees from close to 20 countries presented over 100 contributions at this meeting in which many aspects of the current activities in turbulence research were covered. Five topics received particular attention at the Symposium: Free Flows Wall Flows Recirculating Flows Developments in Reynolds Stress Closures New Directions in Modeling This is also reflected in the five chapters of this book with contributions from research workers from different countries. Each chapter covers the most valuable contributions of the conference to the particular chapter topic. Of course, there were many additional good con tributions to each subject at the meeting but the limitation imposed on the length of this volume required that a selection be made. The realization of the First International Symposium on Turbulent Shear Flows was p- sible by the general support of: U. S. Army Research Office U. S. Navy Research Office Continuing Education Center of The Pennsylvania State University The conference organization was carried out by the organizing committee consisting of: F. Durst, Universitat Karlsruhe, Karlsruhe, Fed. Rep. of Germany V. W. Goldschmidt, Purdue University, West Lafayette, Ind. , USA B. E. Launder, University of California, Davis, Calif. , USA F. W. Schmidt, Pennsylvania State University, University Park, Penna.
Book Synopsis Large Eddy Simulation for Incompressible Flows by : P. Sagaut
Download or read book Large Eddy Simulation for Incompressible Flows written by P. Sagaut and published by Springer Science & Business Media. This book was released on 2006 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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."
Book Synopsis Improved Turbulence Models Based on Large Eddy Simulation of Homogenous, Incompressible, Turbulent Flows by : Jorge E. Bardina
Download or read book Improved Turbulence Models Based on Large Eddy Simulation of Homogenous, Incompressible, Turbulent Flows written by Jorge E. Bardina and published by . This book was released on 1983 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Modeling Complex Turbulent Flows by : Manuel D. Salas
Download or read book Modeling Complex Turbulent Flows written by Manuel D. Salas and published by Springer Science & Business Media. This book was released on 1999-04-30 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence modeling both addresses a fundamental problem in physics, 'the last great unsolved problem of classical physics,' and has far-reaching importance in the solution of difficult practical problems from aeronautical engineering to dynamic meteorology. However, the growth of supercom puter facilities has recently caused an apparent shift in the focus of tur bulence research from modeling to direct numerical simulation (DNS) and large eddy simulation (LES). This shift in emphasis comes at a time when claims are being made in the world around us that scientific analysis itself will shortly be transformed or replaced by a more powerful 'paradigm' based on massive computations and sophisticated visualization. Although this viewpoint has not lacked ar ticulate and influential advocates, these claims can at best only be judged premature. After all, as one computational researcher lamented, 'the com puter only does what I tell it to do, and not what I want it to do. ' In turbulence research, the initial speculation that computational meth ods would replace not only model-based computations but even experimen tal measurements, have not come close to fulfillment. It is becoming clear that computational methods and model development are equal partners in turbulence research: DNS and LES remain valuable tools for suggesting and validating models, while turbulence models continue to be the preferred tool for practical computations. We believed that a symposium which would reaffirm the practical and scientific importance of turbulence modeling was both necessary and timely.
Book Synopsis Large Eddy Simulation for Incompressible Flows by : Pierre Sagaut
Download or read book Large Eddy Simulation for Incompressible Flows written by Pierre Sagaut and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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."
Book Synopsis Large-Eddy Simulations of Turbulence by : M. Lesieur
Download or read book Large-Eddy Simulations of Turbulence written by M. Lesieur and published by Cambridge University Press. This book was released on 2005-08-22 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large-Eddy Simulations of Turbulence is a reference for LES, direct numerical simulation and Reynolds-averaged Navier-Stokes simulation.
Book Synopsis Mathematical and Numerical Foundations of Turbulence Models and Applications by : Tomás Chacón Rebollo
Download or read book Mathematical and Numerical Foundations of Turbulence Models and Applications written by Tomás Chacón Rebollo and published by Springer. This book was released on 2014-06-17 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: With applications to climate, technology, and industry, the modeling and numerical simulation of turbulent flows are rich with history and modern relevance. The complexity of the problems that arise in the study of turbulence requires tools from various scientific disciplines, including mathematics, physics, engineering and computer science. Authored by two experts in the area with a long history of collaboration, this monograph provides a current, detailed look at several turbulence models from both the theoretical and numerical perspectives. The k-epsilon, large-eddy simulation and other models are rigorously derived and their performance is analyzed using benchmark simulations for real-world turbulent flows. Mathematical and Numerical Foundations of Turbulence Models and Applications is an ideal reference for students in applied mathematics and engineering, as well as researchers in mathematical and numerical fluid dynamics. It is also a valuable resource for advanced graduate students in fluid dynamics, engineers, physical oceanographers, meteorologists and climatologists.
Book Synopsis Direct and Large Eddy Simulation of Turbulence by : NA Schumann
Download or read book Direct and Large Eddy Simulation of Turbulence written by NA Schumann and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 :Luigi Carlo Berselli Publisher :Springer Science & Business Media ISBN 13 :9783540263166 Total Pages :378 pages Book Rating :4.2/5 (631 download)
Book Synopsis Mathematics of Large Eddy Simulation of Turbulent Flows by : Luigi Carlo Berselli
Download or read book Mathematics of Large Eddy Simulation of Turbulent Flows written by Luigi Carlo Berselli and published by Springer Science & Business Media. This book was released on 2006 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: The LES-method is rapidly developing in many practical applications in engineering The mathematical background is presented here for the first time in book form by one of the leaders in the field
Download or read book Turbulent Flows written by Jean Piquet and published by Springer Science & Business Media. This book was released on 2001-03-26 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt: obtained are still severely limited to low Reynolds numbers (about only one decade better than direct numerical simulations), and the interpretation of such calculations for complex, curved geometries is still unclear. It is evident that a lot of work (and a very significant increase in available computing power) is required before such methods can be adopted in daily's engineering practice. I hope to l"Cport on all these topics in a near future. The book is divided into six chapters, each· chapter in subchapters, sections and subsections. The first part is introduced by Chapter 1 which summarizes the equations of fluid mechanies, it is developed in C~apters 2 to 4 devoted to the construction of turbulence models. What has been called "engineering methods" is considered in Chapter 2 where the Reynolds averaged equations al"C established and the closure problem studied (§1-3). A first detailed study of homogeneous turbulent flows follows (§4). It includes a review of available experimental data and their modeling. The eddy viscosity concept is analyzed in §5 with the l"Csulting ~alar-transport equation models such as the famous K-e model. Reynolds stl"Css models (Chapter 4) require a preliminary consideration of two-point turbulence concepts which are developed in Chapter 3 devoted to homogeneous turbulence. We review the two-point moments of velocity fields and their spectral transforms (§ 1), their general dynamics (§2) with the particular case of homogeneous, isotropie turbulence (§3) whel"C the so-called Kolmogorov's assumptions are discussed at length.
Book Synopsis Machine Learning Methods for Modeling Turbulence in Large Eddy Simulations by : Marius Kurz
Download or read book Machine Learning Methods for Modeling Turbulence in Large Eddy Simulations written by Marius Kurz and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reliable prediction of turbulent flows is of crucial importance since turbulence is prevalent in the majority of flows found in science and engineering. Turbulence is a multi-scale phenomenon, for which flow features can span several orders of magnitude in size. This results in enormous resolution requirements in numerical simulations of turbulent flow. The framework of large eddy simulation relaxes these resolution demands by resolving only the largest, most energetic features of the flow and approximating the dynamics of the smaller, unresolved scales with turbulence models. The goal of this thesis is to leverage the recent advances in machine learning methods to formulate data-driven modeling strategies for implicitly filtered large eddy simulation. To this end, two modeling strategies are devised based on the supervised and the reinforcement learning paradigms. First, artificial neural networks are trained using supervised learning to recover the unknown closure terms from the filtered flow field. It is demonstrated that recurrent neural networks can predict the unknown closure terms with excellent accuracy. The second modeling strategy is based on the reinforcement learning paradigm. For this, Relexi is introduced as a novel reinforcement learning framework that allows to employ legacy flow solvers as training environments at scale. With Relexi, artificial neural networks are trained within forced homogeneous isotropic turbulence to adapt the parameters of traditional turbulence models dynamically in space and time. The trained models provide accurate and stable simulations and generalize well to other resolutions and higher Reynolds numbers. It is demonstrated within this thesis that machine learning methods can be applied to derive data-driven turbulence models for implicitly filtered large eddy simulation and that these models can be trained and incorporated efficiently into practical simulations on high-performance computing systems.
Book Synopsis Higher-level Simulations of Turbulent Flows by : J. H. Ferziger
Download or read book Higher-level Simulations of Turbulent Flows written by J. H. Ferziger and published by . This book was released on 1981 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The five major categories of this paper are: Correlations, Integral methods, Reynolds-averaged equations, large eddy simulation, and full simulation.
Book Synopsis Data-driven Dynamic Nonlocal Subgrid-scale Modeling for the Large Eddy Simulation of Turbulent Flows by : Seyedhadi Seyedi
Download or read book Data-driven Dynamic Nonlocal Subgrid-scale Modeling for the Large Eddy Simulation of Turbulent Flows written by Seyedhadi Seyedi and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study aims to propose novel solutions to the complex problem of turbulent flows using data-driven statistical and mathematical models. The proposed models reduce the huge computational cost of the direct numerical simulations and make them tractable while maintaining the important statistical features of the chaotic flows. Unlike the conventional models in the literature, the new proposed dynamic models take into account the inherent nonlocality of turbulence and predict the final statistical quantities with higher accuracy and correlations. First, we developed a novel autonomously dynamic nonlocal turbulence model for the large and very large eddy simulation (LES, VLES) of the homogeneous isotropic turbulent flows (HIT). The model is based on a generalized (integer-to-noninteger) order Laplacian of the filtered velocity field, and a novel dynamic model has been formulated to avoid the need for tuning the model constant. Three data-driven approaches were introduced for the determination of the fractional-order to have a model which is totally free of any tuning parameter. Our analysis includes both the a priori and the a posteriori tests. In the former test, using a high-fidelity and well-resolved dataset from direct numerical simulations (DNS), we computed the correlation coefficients for the stress components of the subgrid-scale (SGS) stress tensor and the one we get directly from the DNS results. Moreover, we compared the probability density function of the ensemble-averaged SGS forces for different filter sizes. In the latter, we employed our new model along with other conventional models including static and dynamic Smagorinsky into our pseudo-spectral solver and tested the final predicted quantities. The results of the newly developed model exhibit an expressive agreement with the ground-truth DNS results in all components of the SGS stress and forces. Also, the model exhibits promising results in the VLES region as well as the LES region, which could be remarkably important for the cost-efficient nonlocal turbulence modeling e.g., in meteorological and environmental applications.Afterwards, we extend the same dynamic nonlocal idea to the scalar turbulence. To this end, we formulate the underlying nonlocal model starting from the filtered Boltzmann kinetic transport equation, where the divergence of subgrid-scale scalar fluxes emerges as a fractional-order Laplacian term in the filtered advection-diffusion model, coding the corresponding super-diffusive nature of scalar turbulence. Subsequently, we develop a robust data-driven algorithm for estimation of the fractional (non-integer) Laplacian exponent, where we on-the-fly calculate the corresponding model coefficient employing a new dynamic procedure. Our a priori tests show that our new dynamically nonlocal LES paradigm provides better agreements with the ground-truth filtered DNS data in comparison to the conventional static and dynamic Prandtl-Smagorisnky models. Moreover, in order to analyze the numerical stability and assessing the model's performance, we carry out a comprehensive a posteriori tests. They unanimously illustrate that our new model considerably outperforms other existing functional models, correctly predicting the backscattering phenomena at the same time and providing higher correlations at small-to-large filter sizes. We conclude that our proposed nonlocal subgrid-scale model for scalar turbulence is amenable for coarse LES and VLES frameworks even with strong anisotropies, applicable to environmental applications.Finally, we developed a new dynamic tempered fractional subgrid-scale model, DTF, for the large and very large eddy simulation of turbulent flows. The nonlocality of the turbulent flows is the innate feature that can be seen in the non-Gaussian statistics of the velocity increments and can be addressed properly by the nonlocal models in terms of the fractional operators. Using kinetic transport, we developed a dynamic tempered fractional model that encompasses the three main characteristics of an ideal turbulence model: (i) nonlocal nature, (ii) dynamic model constant computations, and (iii) tempered and finite variance property. Several simulations of forced homogeneous isotropic and multi-layer temporal shear layer turbulent flows have been done in the a priori and a posteriori analyses. The results show that the new model is not only numerically stable and can maintain low- and high-order structures in long-range simulations, but it also provides better predictions than local models and nontempered models.
Book Synopsis Homogeneous Turbulence Dynamics by : Pierre Sagaut
Download or read book Homogeneous Turbulence Dynamics written by Pierre Sagaut and published by Springer. This book was released on 2018-03-23 with total page 912 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides state-of-the-art results and theories in homogeneous turbulence, including anisotropy and compressibility effects with extension to quantum turbulence, magneto-hydodynamic turbulence and turbulence in non-newtonian fluids. Each chapter is devoted to a given type of interaction (strain, rotation, shear, etc.), and presents and compares experimental data, numerical results, analysis of the Reynolds stress budget equations and advanced multipoint spectral theories. The role of both linear and non-linear mechanisms is emphasized. The link between the statistical properties and the dynamics of coherent structures is also addressed. Despite its restriction to homogeneous turbulence, the book is of interest to all people working in turbulence, since the basic physical mechanisms which are present in all turbulent flows are explained. The reader will find a unified presentation of the results and a clear presentation of existing controversies. Special attention is given to bridge the results obtained in different research communities. Mathematical tools and advanced physical models are detailed in dedicated chapters.
Book Synopsis Toward the Large-eddy Simulations of Compressible Turbulent Flows by :
Download or read book Toward the Large-eddy Simulations of Compressible Turbulent Flows written by and published by . This book was released on 1987 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Advanced Approaches in Turbulence by : Paul Durbin
Download or read book Advanced Approaches in Turbulence written by Paul Durbin and published by Elsevier. This book was released on 2021-07-24 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Approaches in Turbulence: Theory, Modeling, Simulation and Data Analysis for Turbulent Flows focuses on the updated theory, simulation and data analysis of turbulence dealing mainly with turbulence modeling instead of the physics of turbulence. Beginning with the basics of turbulence, the book discusses closure modeling, direct simulation, large eddy simulation and hybrid simulation. The book also covers the entire spectrum of turbulence models for both single-phase and multi-phase flows, as well as turbulence in compressible flow. Turbulence modeling is very extensive and continuously updated with new achievements and improvements of the models. Modern advances in computer speed offer the potential for elaborate numerical analysis of turbulent fluid flow while advances in instrumentation are creating large amounts of data. This book covers these topics in great detail. Covers the fundamentals of turbulence updated with recent developments Focuses on hybrid methods such as DES and wall-modeled LES Gives an updated treatment of numerical simulation and data analysis
