Calculation of Complex Turbulent Flows

Calculation of Complex Turbulent Flows PDF Author: George Tzabiras
Publisher: Witpress
ISBN:
Category : Science
Languages : en
Pages : 424

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Book Description
A selection of invited chapters focusing on developments in the application of Computational Fluid Dynamics (CFD) to compressible or incompressible flows dominated by turbulence effects. These may be applied to complex geometrical configurations or flow-fields in simpler geometries requiring higher-order turbulence modelling, or suitably modified low-order models, to calculate crucial parameters such as instabilities, transition, separation, accurate description of velocity and scalar fields, and local and total forces.

Calculation of Complex Turbulent Flows

Calculation of Complex Turbulent Flows PDF Author: George Tzabiras
Publisher: Witpress
ISBN:
Category : Science
Languages : en
Pages : 424

Get Book Here

Book Description
A selection of invited chapters focusing on developments in the application of Computational Fluid Dynamics (CFD) to compressible or incompressible flows dominated by turbulence effects. These may be applied to complex geometrical configurations or flow-fields in simpler geometries requiring higher-order turbulence modelling, or suitably modified low-order models, to calculate crucial parameters such as instabilities, transition, separation, accurate description of velocity and scalar fields, and local and total forces.

Calculation of Complex Turbulent Flows

Calculation of Complex Turbulent Flows PDF Author: George Tzabiras
Publisher:
ISBN:
Category : Turbulence
Languages : en
Pages : 400

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Book Description


Modeling Complex Turbulent Flows

Modeling Complex Turbulent Flows PDF Author: Manuel D. Salas
Publisher: Springer Science & Business Media
ISBN: 9401147248
Category : Science
Languages : en
Pages : 385

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Book Description
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.

Calculation of Reattaching Shear Layers in Divergent Channel with a Multiple-time-scale Turbulence Model

Calculation of Reattaching Shear Layers in Divergent Channel with a Multiple-time-scale Turbulence Model PDF Author: S.-W. Kim
Publisher:
ISBN:
Category :
Languages : en
Pages : 30

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Book Description


Advanced Turbulent Flow Computations

Advanced Turbulent Flow Computations PDF Author: Roger Peyret
Publisher: Springer
ISBN: 3709125901
Category : Science
Languages : en
Pages : 320

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Book Description
This book collects the lecture notes concerning the IUTAM School on Advanced Turbulent Flow Computations held at CISM in Udine September 7–11, 1998. The course was intended for scientists, engineers and post-graduate students interested in the application of advanced numerical techniques for simulating turbulent flows. The topic comprises two closely connected main subjects: modelling and computation, mesh pionts necessary to simulate complex turbulent flow.

Turbulent Flows

Turbulent Flows PDF Author: G. Biswas
Publisher: CRC Press
ISBN: 9780849310140
Category : Technology & Engineering
Languages : en
Pages : 478

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Book Description
This book allows readers to tackle the challenges of turbulent flow problems with confidence. It covers the fundamentals of turbulence, various modeling approaches, and experimental studies. The fundamentals section includes isotropic turbulence and anistropic turbulence, turbulent flow dynamics, free shear layers, turbulent boundary layers and plumes. The modeling section focuses on topics such as eddy viscosity models, standard K-E Models, Direct Numerical Stimulation, Large Eddy Simulation, and their applications. The measurement of turbulent fluctuations experiments in isothermal and stratified turbulent flows are explored in the experimental methods section. Special topics include modeling of near wall turbulent flows, compressible turbulent flows, and more.

Turbulent Flow Computation

Turbulent Flow Computation PDF Author: D. Drikakis
Publisher: Springer Science & Business Media
ISBN: 0306484218
Category : Science
Languages : en
Pages : 390

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Book Description
In various branches of fluid mechanics, our understanding is inhibited by the presence of turbulence. Although many experimental and theoretical studies have significantly helped to increase our physical understanding, a comp- hensive and predictive theory of turbulent flows has not yet been established. Therefore, the prediction of turbulent flow relies heavily on simulation stra- gies. The development of reliable methods for turbulent flow computation will have a significant impact on a variety of technological advancements. These range from aircraft and car design, to turbomachinery, combustors, and process engineering. Moreover, simulation approaches are important in materials - sign, prediction of biologically relevant flows, and also significantly contribute to the understanding of environmental processes including weather and climate forecasting. The material that is compiled in this book presents a coherent account of contemporary computational approaches for turbulent flows. It aims to p- vide the reader with information about the current state of the art as well as to stimulate directions for future research and development. The book puts part- ular emphasis on computational methods for incompressible and compressible turbulent flows as well as on methods for analysing and quantifying nume- cal errors in turbulent flow computations. In addition, it presents turbulence modelling approaches in the context of large eddy simulation, and unfolds the challenges in the field of simulations for multiphase flows and computational fluid dynamics (CFD) of engineering flows in complex geometries. Apart from reviewing main research developments, new material is also included in many of the chapters.

Statistical Mechanics of Turbulent Flows

Statistical Mechanics of Turbulent Flows PDF Author: Stefan Heinz
Publisher: Springer Science & Business Media
ISBN: 3662100223
Category : Science
Languages : en
Pages : 232

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Book Description
The simulation of technological and environmental flows is very important for many industrial developments. A major challenge related to their modeling is to involve the characteristic turbulence that appears in most of these flows. The traditional way to tackle this question is to use deterministic equations where the effects of turbulence are directly parametrized, i. e. , assumed as functions of the variables considered. However, this approach often becomes problematic, in particular if reacting flows have to be simulated. In many cases, it turns out that appropriate approximations for the closure of deterministic equations are simply unavailable. The alternative to the traditional way of modeling turbulence is to construct stochastic models which explain the random nature of turbulence. The application of such models is very attractive: one can overcome the closure problems that are inherent to deterministic methods on the basis of relatively simple and physically consistent models. Thus, from a general point of view, the use of stochastic methods for turbulence simulations seems to be the optimal way to solve most of the problems related to industrial flow simulations. However, it turns out that this is not as simple as it looks at first glance. The first question concerns the numerical solution of stochastic equations for flows of environmental and technological interest. To calculate industrial flows, 3 one often has to consider a number of grid cells that is of the order of 100 .

Engineering Calculation Methods for Turbulent Flow

Engineering Calculation Methods for Turbulent Flow PDF Author: Peter Bradshaw
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 352

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Book Description


Turbulent Flows

Turbulent Flows PDF Author: Jean Piquet
Publisher: Springer Science & Business Media
ISBN: 9783540654117
Category : Technology & Engineering
Languages : en
Pages : 778

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Book Description
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.