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Author: Rainer Friedrich Publisher: Springer Science & Business Media ISBN: 0306483831 Category : Technology & Engineering Languages : en Pages : 387
Book Description
The articles focus on new developments in the field of large-eddy simulation of complex flows and are related to the topics: modelling and analysis of subgrid scales, numerical issues in LES cartesian grids for complex geometries, curvilinear and non-structured grids for complex geometries. DES and RANS-LES coupling, aircraft wake vortices, combustion and magnetohydrodynamics. Progress has been made not only in understanding and modelling the dynamics of unresolved scales, but also in designing means that prevent the contamination of LES predictions by discretization errors. Progress is reported as well on the use of cartesian and curvilinear coordinates to compute flow in and around complex geometries and in the field of LES with unstructured grids. A chapter is dedicated to the detached-eddy simulation technique and its recent achievements and to the promising technique of coupling RANS and LES solutions in order to push the resolution-based Reynolds number limit of wall-resolving LES to higher values. Complexity due to physical mechanisms links the last two chapters. It is shown that LES constitutes the tool to analyse the physics of aircraft wake vortices during landing and takeoff. Its thorough understanding is a prerequisite for reliable predictions of the distance between consecutive landing airplanes. Subgrid combustion modelling for LES of single and two-phase reacting flows is demonstrated to have the potential to deal with finite-rate kinetics in high Reynolds number flows of full-scale gas turbine engines. Fluctuating magnetic fields are more reliably predicted by LES when tensor-diffusivity rather than gradient-diffusion models are used. An encouraging result in the context of turbulence control by magnetic fields.
Author: Rainer Friedrich Publisher: Springer Science & Business Media ISBN: 0306483831 Category : Technology & Engineering Languages : en Pages : 387
Book Description
The articles focus on new developments in the field of large-eddy simulation of complex flows and are related to the topics: modelling and analysis of subgrid scales, numerical issues in LES cartesian grids for complex geometries, curvilinear and non-structured grids for complex geometries. DES and RANS-LES coupling, aircraft wake vortices, combustion and magnetohydrodynamics. Progress has been made not only in understanding and modelling the dynamics of unresolved scales, but also in designing means that prevent the contamination of LES predictions by discretization errors. Progress is reported as well on the use of cartesian and curvilinear coordinates to compute flow in and around complex geometries and in the field of LES with unstructured grids. A chapter is dedicated to the detached-eddy simulation technique and its recent achievements and to the promising technique of coupling RANS and LES solutions in order to push the resolution-based Reynolds number limit of wall-resolving LES to higher values. Complexity due to physical mechanisms links the last two chapters. It is shown that LES constitutes the tool to analyse the physics of aircraft wake vortices during landing and takeoff. Its thorough understanding is a prerequisite for reliable predictions of the distance between consecutive landing airplanes. Subgrid combustion modelling for LES of single and two-phase reacting flows is demonstrated to have the potential to deal with finite-rate kinetics in high Reynolds number flows of full-scale gas turbine engines. Fluctuating magnetic fields are more reliably predicted by LES when tensor-diffusivity rather than gradient-diffusion models are used. An encouraging result in the context of turbulence control by magnetic fields.
Author: Christophe Brun Publisher: Springer Science & Business Media ISBN: 3540899561 Category : Technology & Engineering Languages : en Pages : 344
Book Description
Large Eddy Simulation (LES) is a high-fidelity approach to the numerical simulation of turbulent flows. Recent developments have shown LES to be able to predict aerodynamic noise generation and propagation as well as the turbulent flow, by means of either a hybrid or a direct approach. This book is based on the results of two French/German research groups working on LES simulations in complex geometries and noise generation in turbulent flows. The results provide insights into modern prediction approaches for turbulent flows and noise generation mechanisms as well as their use for novel noise reduction concepts.
Author: Tapan Kumar Sengupta Publisher: World Scientific ISBN: 9814635162 Category : Science Languages : en Pages : 551
Book Description
"The role of high performance computing in current research on transitional and turbulent flows is undoubtedly very important. This review volume provides a good platform for leading experts and researchers in various fields of fluid mechanics dealing with transitional and turbulent flows to synergistically exchange ideas and present the state of the art in the fields. Contributed by eminent researchers, the book chapters feature keynote lectures, panel discussions and the best invited contributed papers."--
Author: Maria Vittoria Salvetti Publisher: Springer ISBN: 3030049159 Category : Technology & Engineering Languages : en Pages : 608
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.
Author: Stavros Kassinos Publisher: Springer Science & Business Media ISBN: 3540342346 Category : Technology & Engineering Languages : en Pages : 440
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.
Author: Paul Durbin Publisher: Elsevier ISBN: 0128207744 Category : Technology & Engineering Languages : en Pages : 552
Book Description
Front Cover -- Advanced Approaches in Turbulence -- Copyright -- Contents -- Contributors -- Preface -- 1 Basics of turbulence -- 1.1 Introduction -- 1.2 Eddy diffusion -- 1.3 Scales of turbulence -- 1.3.1 Isotropic decay -- 1.3.2 Stretching and diffusion of vorticity -- 1.4 Spectral equations -- 1.4.1 Isotropic turbulence -- 1.4.2 Shear and streaks -- 1.5 Averaged equations -- 1.5.1 Jets -- 1.5.2 Boundary layer -- 1.6 The form of turbulence models -- 1.6.1 Two equation models -- 1.6.2 Reynolds stress transport -- 1.7 Conclusion -- References -- 2 Direct numerical and large-eddy simulation of complex turbulent flows -- 2.1 Introduction -- 2.2 Error as a function of scale -- 2.2.1 Modified wavenumber -- 2.2.2 Nonlinear sources of error -- 2.2.3 Time advancement error as a function of scale -- 2.3 Analysis of numerical errors in large-eddy simulation using statistical closure theory -- 2.3.1 EDQNM closure -- 2.3.2 EDQNM-LES and the inclusion of numerical error -- 2.3.3 EDQNM model -- 2.3.4 Relative magnitudes of error -- 2.4 Simulations in complex geometries -- 2.4.1 Decay of isotropic turbulence -- 2.4.2 Gas turbine combustor -- 2.5 Simulating the flow around moving bodies -- 2.5.1 Fluid phase -- 2.5.2 Solid phase -- 2.5.3 The effects of interpolation -- 2.5.4 Particles in a turbulent channel -- 2.6 What is a 'canonical' flow? -- 2.6.1 Jets in crossflow -- 2.6.2 DNS of turbulent channel flow over random rough surfaces -- 2.7 The analysis of 'big data' -- 2.7.1 DMD of large datasets and numerical error -- 2.7.2 Analysis of wall-pressure fluctuation sources in turbulent channel flow -- 2.8 Bridging the Reynolds number divide -- 2.9 Concluding remarks -- Acknowledgments -- References -- 3 Large-eddy simulations -- 3.1 Introduction -- 3.1.1 Motivation -- 3.2 Governing equations -- 3.2.1 Filtering.
Author: Marianna Braza Publisher: Springer Nature ISBN: 3030555941 Category : Technology & Engineering Languages : en Pages : 599
Book Description
This book reports on the latest knowledge concerning critical phenomena arising in fluid-structure interaction due to movement and/or deformation of bodies. The focus of the book is on reporting progress in understanding turbulence and flow control to improve aerodynamic / hydrodynamic performance by reducing drag, increasing lift or thrust and reducing noise under critical conditions that may result in massive separation, strong vortex dynamics, amplification of harmful instabilities (flutter, buffet), and flow -induced vibrations. Theory together with large-scale simulations and experiments have revealed new features of turbulent flow in the boundary layer over bodies and in thin shear layers immediately downstream of separation. New insights into turbulent flow interacting with actively deformable structures, leading to new ways of adapting and controlling the body shape and vibrations to respond to these critical conditions, are investigated. The book covers new features of turbulent flows in boundary layers over wings and in shear layers immediately downstream: studies of natural and artificially generated fluctuations; reduction of noise and drag; and electromechanical conversion topics. Smart actuators as well as how smart designs lead to considerable benefits compared with conventional methods are also extensively discussed. Based on contributions presented at the IUTAM Symposium “Critical Flow Dynamics involving Moving/Deformable Structures with Design applications”, held in June 18-22, 2018, in Santorini, Greece, the book provides readers with extensive information about current theories, methods and challenges in flow and turbulence control, and practical knowledge about how to use this information together with smart and bio-inspired design tools to improve aerodynamic and hydrodynamic design and safety.
Author: Song Fu Publisher: Springer Science & Business Media ISBN: 3642318185 Category : Technology & Engineering Languages : en Pages : 508
Book Description
The present book contains contributions presented at the Fourth Symposium on Hybrid RANS-LES Methods, held in Beijing, China, 28-30 September 2011, being a continuation of symposia taking place in Stockholm (Sweden, 2005), in Corfu (Greece, 2007), and Gdansk (Poland, 2009). The contributions to the last two symposia were published as NNFM, Vol. 97 and Vol. 111. At the Beijing symposium, along with seven invited keynotes, another 46 papers (plus 5 posters) were presented addressing topics on Novel turbulence-resolving simulation and modelling, Improved hybrid RANS-LES methods, Comparative studies of difference modelling methods, Modelling-related numerical issues and Industrial applications.. The present book reflects recent activities and new progress made in the development and applications of hybrid RANS-LES methods in general.
Author: S. Hernández Publisher: WIT Press ISBN: 1784664359 Category : Science Languages : en Pages : 194
Book Description
The field of fluid mechanics is vast and has numerous and diverse applications. Presented papers from the 11th International Conference on Advances in Fluid Dynamics with emphasis on Multiphase and Complex Flow are contained in this book and cover a wide range of topics, including basic formulations and their computer modelling as well as the relationship between experimental and analytical results. Innovation in fluid-structure approaches including emerging applications as energy harvesting systems, studies of turbulent flows at high Reynold number, or subsonic and hypersonic flows are also among the topics covered. The emphasis placed on multiphase flow in the included research works is due to the fact that fluid dynamics processes in nature are predominantly multi-phased, i.e. involving more than one phase of a component such as liquid, gas or plasma. The range of related problems of interest is vast: astrophysics, biology, geophysics, atmospheric processes, and a large variety of engineering applications. Multiphase fluid dynamics are generating a great deal of interest, leading to many notable advances in experimental, analytical, and numerical studies in this area. While progress is continuing in all three categories, advances in numerical solutions are likely the most conspicuous, owing to the continuing improvements in computer power and the software tools available to researchers. Progress in numerical methods has not only allowed for the solution of many practical problems but also helped to improve our understanding of the physics involved. Many unresolved issues are inherent in the very definition of multiphase flow, where it is necessary to consider coupled processes on multiple scales, as well as the interplay of a wide variety of relevant physical phenomena.
Author: Yannick Hoarau Publisher: Springer Nature ISBN: 3030276074 Category : Technology & Engineering Languages : en Pages : 412
Book Description
This book gathers the proceedings of the Seventh Symposium on Hybrid RANS-LES Methods, which was held on September 17-19 in Berlin, Germany. The different chapters, written by leading experts, reports on the most recent developments in flow physics modelling, and gives a special emphasis to industrially relevant applications of hybrid RANS-LES methods and other turbulence-resolving modelling approaches. The book addresses academic researchers, graduate students, industrial engineers, as well as industrial R&D managers and consultants dealing with turbulence modelling, simulation and measurement, and with multidisciplinary applications of computational fluid dynamics (CFD), such as flow control, aero-acoustics, aero-elasticity and CFD-based multidisciplinary optimization. It discusses in particular advanced hybrid RANS-LES methods. Further topics include wall-modelled Large Eddy Simulation (WMLES) methods, embedded LES, Lattice-Bolzman methods and turbulence-resolving applications and a comparison of the LES methods with both hybrid RANS-LES and URANS methods. Overall, the book provides readers with a snapshot on the state-of-the-art in CFD and turbulence modelling, with a special focus to hybrid RANS-LES methods and their industrial applications.
Author: Rainer Friedrich
Author: Rainer Friedrich
Author: Christophe Brun
Author: Tapan Kumar Sengupta
Author: Maria Vittoria Salvetti
Author: Stavros Kassinos
Author: Paul Durbin
Author: Marianna Braza
Author: Song Fu
Author: S. Hernández
Author: Yannick Hoarau