Direct and Large-Eddy Simulation I

Direct and Large-Eddy Simulation I PDF Author: Peter R. Voke
Publisher: Springer Science & Business Media
ISBN: 9780792331063
Category : Technology & Engineering
Languages : en
Pages : 454

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Book Description
It is a truism that turbulence is an unsolved problem, whether in scientific, engin eering or geophysical terms. It is strange that this remains largely the case even though we now know how to solve directly, with the help of sufficiently large and powerful computers, accurate approximations to the equations that govern tur bulent flows. The problem lies not with our numerical approximations but with the size of the computational task and the complexity of the solutions we gen erate, which match the complexity of real turbulence precisely in so far as the computations mimic the real flows. The fact that we can now solve some turbu lence in this limited sense is nevertheless an enormous step towards the goal of full understanding. Direct and large-eddy simulations are these numerical solutions of turbulence. They reproduce with remarkable fidelity the statistical, structural and dynamical properties of physical turbulent and transitional flows, though since the simula tions are necessarily time-dependent and three-dimensional they demand the most advanced computer resources at our disposal. The numerical techniques vary from accurate spectral methods and high-order finite differences to simple finite-volume algorithms derived on the principle of embedding fundamental conservation prop erties in the numerical operations. Genuine direct simulations resolve all the fluid motions fully, and require the highest practical accuracy in their numerical and temporal discretisation. Such simulations have the virtue of great fidelity when carried out carefully, and repre sent a most powerful tool for investigating the processes of transition to turbulence.

Direct and Large-Eddy Simulation I

Direct and Large-Eddy Simulation I PDF Author: Peter R. Voke
Publisher: Springer Science & Business Media
ISBN: 9780792331063
Category : Technology & Engineering
Languages : en
Pages : 454

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Book Description
It is a truism that turbulence is an unsolved problem, whether in scientific, engin eering or geophysical terms. It is strange that this remains largely the case even though we now know how to solve directly, with the help of sufficiently large and powerful computers, accurate approximations to the equations that govern tur bulent flows. The problem lies not with our numerical approximations but with the size of the computational task and the complexity of the solutions we gen erate, which match the complexity of real turbulence precisely in so far as the computations mimic the real flows. The fact that we can now solve some turbu lence in this limited sense is nevertheless an enormous step towards the goal of full understanding. Direct and large-eddy simulations are these numerical solutions of turbulence. They reproduce with remarkable fidelity the statistical, structural and dynamical properties of physical turbulent and transitional flows, though since the simula tions are necessarily time-dependent and three-dimensional they demand the most advanced computer resources at our disposal. The numerical techniques vary from accurate spectral methods and high-order finite differences to simple finite-volume algorithms derived on the principle of embedding fundamental conservation prop erties in the numerical operations. Genuine direct simulations resolve all the fluid motions fully, and require the highest practical accuracy in their numerical and temporal discretisation. Such simulations have the virtue of great fidelity when carried out carefully, and repre sent a most powerful tool for investigating the processes of transition to turbulence.

Turbulent Flow in a 180 ̊bend

Turbulent Flow in a 180 ̊bend PDF Author: Upender Krishnen Kaul
Publisher:
ISBN:
Category : Turbulence
Languages : en
Pages : 60

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Book Description


Measurement and Calculation of Developing Turbulent Flow in a U-bend and Downstream Tangent of Square Cross-section

Measurement and Calculation of Developing Turbulent Flow in a U-bend and Downstream Tangent of Square Cross-section PDF Author: Shengming Chang
Publisher:
ISBN:
Category :
Languages : en
Pages : 332

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Book Description


Engineering Turbulence Modelling and Experiments - 3

Engineering Turbulence Modelling and Experiments - 3 PDF Author: G. Bergeles
Publisher: Newnes
ISBN: 0444600132
Category : Technology & Engineering
Languages : en
Pages : 932

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Book Description
This book presents and discussses new developments in the area of turbulence modelling and measurements, with particular emphasis on engineering-related problems. At present, turbulence is one of the key issues in tackling engineering flow problems. Powerful computers and numerical methods are now available for solving the flow equations, but the simulation of turbulence effects which are nearly always important in practice, is still in an unsatisfactory state and introduces considerable uncertainities in the accuracy of CFD calculations. These and other aspects of turbulence modelling and measurements are dealt with in detail by experts in the field. The resulting book is an up-to-date review of the most recent research in this exciting area.

Engineering Turbulence Modelling and Experiments 6

Engineering Turbulence Modelling and Experiments 6 PDF Author: Wolfgang Rodi
Publisher: Elsevier
ISBN: 0080530958
Category : Science
Languages : en
Pages : 1011

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Book Description
Proceedings of the world renowned ERCOFTAC (International Symposium on Engineering Turbulence Modelling and Measurements).The proceedings include papers dealing with the following areas of turbulence:·Eddy-viscosity and second-order RANS models ·Direct and large-eddy simulations and deductions for conventional modelling ·Measurement and visualization techniques, experimental studies ·Turbulence control ·Transition and effects of curvature, rotation and buoyancy on turbulence ·Aero-acoustics ·Heat and mass transfer and chemically reacting flows ·Compressible flows, shock phenomena ·Two-phase flows ·Applications in aerospace engineering, turbomachinery and reciprocating engines, industrial aerodynamics and wind engineering, and selected chemical engineering problems Turbulence remains one of the key issues in tackling engineering flow problems. These problems are solved more and more by CFD analysis, the reliability of which depends strongly on the performance of the turbulence models employed. Successful simulation of turbulence requires the understanding of the complex physical phenomena involved and suitable models for describing the turbulent momentum, heat and mass transfer. For the understanding of turbulence phenomena, experiments are indispensable, but they are equally important for providing data for the development and testing of turbulence models and hence for CFD software validation. As in other fields of Science, in the rapidly developing discipline of turbulence, swift progress can be achieved only by keeping up to date with recent advances all over the world and by exchanging ideas with colleagues active in related fields.

Turbulent Flows

Turbulent Flows PDF Author: Jean Piquet
Publisher: Springer Science & Business Media
ISBN: 3662035596
Category : Technology & Engineering
Languages : en
Pages : 767

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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.

Computational Fluid Dynamics

Computational Fluid Dynamics PDF Author: Jiyuan Tu
Publisher: Butterworth-Heinemann
ISBN: 0080982433
Category : Computers
Languages : en
Pages : 458

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Book Description
An introduction to CFD fundamentals and using commercial CFD software to solve engineering problems, designed for the wide variety of engineering students new to CFD, and for practicing engineers learning CFD for the first time. Combining an appropriate level of mathematical background, worked examples, computer screen shots, and step by step processes, this book walks the reader through modeling and computing, as well as interpreting CFD results. The first book in the field aimed at CFD users rather than developers. New to this edition: A more comprehensive coverage of CFD techniques including discretisation via finite element and spectral element as well as finite difference and finite volume methods and multigrid method. Coverage of different approaches to CFD grid generation in order to closely match how CFD meshing is being used in industry. Additional coverage of high-pressure fluid dynamics and meshless approach to provide a broader overview of the application areas where CFD can be used. 20% new content .

Transport Phenomena in Rotating Machinery

Transport Phenomena in Rotating Machinery PDF Author: J. H. Kim
Publisher: CRC Press
ISBN: 9781560320135
Category : Science
Languages : en
Pages : 572

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Book Description
Completing the authoritative coverage begun in Dynamics of Rotating Machinery, this text offers 36 current chapters focusing on the areas of fluid flow, heat transfer, multiple flow, cavitation and design.

Modelling and Simulation of Turbulent Heat Transfer

Modelling and Simulation of Turbulent Heat Transfer PDF Author: B. Sundén
Publisher: WIT Press
ISBN: 1853129569
Category : Science
Languages : en
Pages : 361

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Book Description
Providing invaluable information for both graduate researchers and R & D engineers in industry and consultancy, this book focuses on the modelling and simulation of fluid flow and thermal transport phenomena in turbulent convective flows. Its overall objective is to present state-of-the-art knowledge in order to predict turbulent heat transfer processes in fundamental and idealized flows as well as in engineering applications. The chapters, which are invited contributions from some of the most prominent scientists in this field, cover a wide range of topics and follow a unified outline and presentation to aid accessibility.

Handbook of Machinery Dynamics

Handbook of Machinery Dynamics PDF Author: Lynn Faulkner
Publisher: CRC Press
ISBN: 1482270374
Category : Technology & Engineering
Languages : en
Pages : 597

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Book Description
Considering a broad range of fundamental factors and conditions influencing the optimal design and operation of machinery, the Handbook of Machinery Dynamics emphasizes the force and motion analysis of machine components in multiple applications. Containing details on basic theories and particular problems, the Handbook of Machinery Dynamics