Numerical Investigation of Steady and Unsteady Flows Comparing Turbulence Models and Different Near-wall Models

Numerical Investigation of Steady and Unsteady Flows Comparing Turbulence Models and Different Near-wall Models PDF Author: Stefan Jansson
Publisher:
ISBN:
Category :
Languages : en
Pages : 52

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Numerical Investigation of Steady and Unsteady Flows Comparing Turbulence Models and Different Near-wall Models

Numerical Investigation of Steady and Unsteady Flows Comparing Turbulence Models and Different Near-wall Models PDF Author: Stefan Jansson
Publisher:
ISBN:
Category :
Languages : en
Pages : 52

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Numerical Simulation of Unsteady Flows and Transition to Turbulence

Numerical Simulation of Unsteady Flows and Transition to Turbulence PDF Author: O. Pironneau
Publisher: Cambridge University Press
ISBN: 9780521416184
Category : Mathematics
Languages : en
Pages : 536

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Book Description
The workshop concentrated on the following turbulence test cases: T1 Boundary layer in an S-shaped duct; T2 Periodic array of cylinders in a channel; T3 Transition in a boundary layer under the influence of free-stream turbulence; T4 & T5: Axisymmetric confined jet flows.

Numerical Investigation of Separated Transonic Turbulent Flows with a Multiple-time-scale Turbulence Model

Numerical Investigation of Separated Transonic Turbulent Flows with a Multiple-time-scale Turbulence Model PDF Author: S. W. Kim
Publisher:
ISBN:
Category : Turbulence
Languages : en
Pages : 44

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Experimental and Numerical Investigation of Developing Turbulent Flow Over a Wavy Wall

Experimental and Numerical Investigation of Developing Turbulent Flow Over a Wavy Wall PDF Author: Vinicius Martins Segunda
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Turbulent flow over a wavy wall in a horizontal channel is investigated by experimental and numerical methods. The thorough problem understanding can advance turbulent flow physics knowledge for separating and reattaching flows. Another important consideration is the performance evaluation of mathematical models used in computational fluid dynamics (CFD) codes to predict the flow characteristics. This study explores numerical models because they are critically important to the design and performance evaluation of engineering systems. The experimental data are obtained to provide repository data and more insights into the flow physics considering both the flow development and fully periodic regions. A channel with a wavy bottom wall is considered for this study, and its main characteristic is a value of 10 for the ratio between the wave length and wave amplitude. A high-resolution particle image velocimetry (PIV) system is used to obtain detailed measurements of velocity at Reynolds number of 5040, 8400, 10700 and 13040 in both the developing and fully periodic regions. The numerical simulations are performed with a commercial CFD code using four eddy viscosity turbulence models and three Second-Moment Closure (SMC) turbulence models. This work assessed the predictive accuracy of a total of seven turbulence models. The experimental study covered a lack of data for the flow development within the waves, prior the periodic condition region, and it supported the turbulence models evaluation. The experiments provided features of the flow such as the recirculation regions, Reynolds stresses, and turbulent kinetic energy production at different channel locations. A comprehensive comparison between models and experimental data revealed a significant dependency on the turbulence model formulation and on the wall treatment selection for the flow development and fully periodic regions predictions.

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 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.

A Rapid-distortion-theory Turbulence Model for Developed Unsteady Wall-bounded Flow

A Rapid-distortion-theory Turbulence Model for Developed Unsteady Wall-bounded Flow PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 22

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A Rapid-distortion-theory Turbulence Model for Developed Unsteady Wall-bounded Flow

A Rapid-distortion-theory Turbulence Model for Developed Unsteady Wall-bounded Flow PDF Author: G. J. Brereton
Publisher:
ISBN:
Category : Turbulence
Languages : en
Pages : 24

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A Numerical Study of Turbulent Flows in Backward-facing Step Geometries: a Comparison of Four Models of Turbulence

A Numerical Study of Turbulent Flows in Backward-facing Step Geometries: a Comparison of Four Models of Turbulence PDF Author: Munir Mehmet Suat Sindir
Publisher:
ISBN:
Category :
Languages : en
Pages : 1282

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Statistical Theory and Modeling for Turbulent Flows

Statistical Theory and Modeling for Turbulent Flows PDF Author: P. A. Durbin
Publisher: John Wiley & Sons
ISBN: 1119957524
Category : Science
Languages : en
Pages : 347

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Book Description
Providing a comprehensive grounding in the subject of turbulence, Statistical Theory and Modeling for Turbulent Flows develops both the physical insight and the mathematical framework needed to understand turbulent flow. Its scope enables the reader to become a knowledgeable user of turbulence models; it develops analytical tools for developers of predictive tools. Thoroughly revised and updated, this second edition includes a new fourth section covering DNS (direct numerical simulation), LES (large eddy simulation), DES (detached eddy simulation) and numerical aspects of eddy resolving simulation. In addition to its role as a guide for students, Statistical Theory and Modeling for Turbulent Flows also is a valuable reference for practicing engineers and scientists in computational and experimental fluid dynamics, who would like to broaden their understanding of fundamental issues in turbulence and how they relate to turbulence model implementation. Provides an excellent foundation to the fundamental theoretical concepts in turbulence. Features new and heavily revised material, including an entire new section on eddy resolving simulation. Includes new material on modeling laminar to turbulent transition. Written for students and practitioners in aeronautical and mechanical engineering, applied mathematics and the physical sciences. Accompanied by a website housing solutions to the problems within the book.