A Multiple-Scale Model for Compressible Turbulent Flows

A Multiple-Scale Model for Compressible Turbulent Flows PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722008796
Category :
Languages : en
Pages : 24

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Book Description
A multiple-scale model for compressible turbulent flows is proposed. It is assumed that turbulent eddy shocklets are formed primarily by the 'collisions' of large energetic eddies. The extra straining of the large eddy, due to their interactions with shocklets, enhances the energy cascade to smaller eddies. Model transport equations are developed for the turbulent kinetic energies and the energy transfer rates of the different scale. The turbulent eddy viscosity is determined by the total turbulent kinetic energy and the rate of energy transfer from the large scale to the small scale, which is different from the energy dissipation rate. The model coefficients in the modeled turbulent transport equations depend on the ratio of the turbulent kinetic energy of the large scale to that of the small scale, which renders the model more adaptive to the characteristics of individual flow. The model is tested against compressible free shear layers. The results agree satisfactorily with measurements. Liou, William W. and Shih, Tsan-Hsing Glenn Research Center NCC3-233; RTOP 505-90-5K...

A Multiple-Scale Model for Compressible Turbulent Flows

A Multiple-Scale Model for Compressible Turbulent Flows PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722008796
Category :
Languages : en
Pages : 24

Get Book Here

Book Description
A multiple-scale model for compressible turbulent flows is proposed. It is assumed that turbulent eddy shocklets are formed primarily by the 'collisions' of large energetic eddies. The extra straining of the large eddy, due to their interactions with shocklets, enhances the energy cascade to smaller eddies. Model transport equations are developed for the turbulent kinetic energies and the energy transfer rates of the different scale. The turbulent eddy viscosity is determined by the total turbulent kinetic energy and the rate of energy transfer from the large scale to the small scale, which is different from the energy dissipation rate. The model coefficients in the modeled turbulent transport equations depend on the ratio of the turbulent kinetic energy of the large scale to that of the small scale, which renders the model more adaptive to the characteristics of individual flow. The model is tested against compressible free shear layers. The results agree satisfactorily with measurements. Liou, William W. and Shih, Tsan-Hsing Glenn Research Center NCC3-233; RTOP 505-90-5K...

Modeling and Simulation of Turbulent Flows

Modeling and Simulation of Turbulent Flows PDF Author: Roland Schiestel
Publisher: John Wiley & Sons
ISBN: 0470393467
Category : Science
Languages : en
Pages : 751

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Book Description
This title provides the fundamental bases for developing turbulence models on rational grounds. The main different methods of approach are considered, ranging from statistical modelling at various degrees of complexity to numerical simulations of turbulence. Each of these various methods has its own specific performances and limitations, which appear to be complementary rather than competitive. After a discussion of the basic concepts, mathematical tools and methods for closure, the book considers second order closure models. Emphasis is placed upon this approach because it embodies potentials for clarifying numerous problems in turbulent shear flows. Simpler, generally older models are then presented as simplified versions of the more general second order models. The influence of extra physical parameters is also considered. Finally, the book concludes by examining large Eddy numerical simulations methods. Given the book’s comprehensive coverage, those involved in the theoretical or practical study of turbulence problems in fluids will find this a useful and informative read.

Workshop on Computational Turbulence Modeling

Workshop on Computational Turbulence Modeling PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 468

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NASA Technical Memorandum

NASA Technical Memorandum PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 492

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Center for Modeling of Turbulence and Transition (CMOTT)

Center for Modeling of Turbulence and Transition (CMOTT) PDF Author:
Publisher:
ISBN:
Category : Turbulence
Languages : en
Pages : 208

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Book Description


Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704

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Book Description


Large Eddy Simulation for Compressible Flows

Large Eddy Simulation for Compressible Flows PDF Author: Eric Garnier
Publisher: Springer Science & Business Media
ISBN: 9048128196
Category : Science
Languages : en
Pages : 280

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Book Description
This book addresses both the fundamentals and the practical industrial applications of Large Eddy Simulation (LES) in order to bridge the gap between LES research and the growing need to use it in engineering modeling.

Monthly Catalog of United States Government Publications

Monthly Catalog of United States Government Publications PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages :

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Multiscale and Multiresolution Approaches in Turbulence

Multiscale and Multiresolution Approaches in Turbulence PDF Author: Pierre Sagaut
Publisher: World Scientific
ISBN: 1848169876
Category : Science
Languages : en
Pages : 446

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Book Description
The book aims to provide the reader with an updated general presentation of multiscale/multiresolution approaches in turbulent flow simulations. All modern approaches (LES, hybrid RANS/LES, DES, SAS) are discussed and recast in a global comprehensive framework. Both theoretical features and practical implementation details are addressed. Some full scale applications are described, to provide the reader with relevant guidelines to facilitate a future use of these methods.

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.