Download or read book A New Time Scale Based K Epsilon Model for Near Wall Turbulence written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-28 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A k-epsilon model is proposed for wall bonded turbulent flows. In this model, the eddy viscosity is characterized by a turbulent velocity scale and a turbulent time scale. The time scale is bounded from below by the Kolmogorov time scale. The dissipation equation is reformulated using this time scale and no singularity exists at the wall. The damping function used in the eddy viscosity is chosen to be a function of R(sub y) = (k(sup 1/2)y)/v instead of y(+). Hence, the model could be used for flows with separation. The model constants used are the same as in the high Reynolds number standard k-epsilon model. Thus, the proposed model will be also suitable for flows far from the wall. Turbulent channel flows at different Reynolds numbers and turbulent boundary layer flows with and without pressure gradient are calculated. Results show that the model predictions are in good agreement with direct numerical simulation and experimental data. Yang, Z. and Shih, T. H. Glenn Research Center NASA ORDER C-99066-6; RTOP 505-62-21...
Download or read book A New Time Scale Based K Epsilon Model for Near Wall Turbulence written by National Aeronautics and Space Administration NASA and published by . This book was released on 2018-10-23 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A k-epsilon model is proposed for wall bonded turbulent flows. In this model, the eddy viscosity is characterized by a turbulent velocity scale and a turbulent time scale. The time scale is bounded from below by the Kolmogorov time scale. The dissipation equation is reformulated using this time scale and no singularity exists at the wall. The damping function used in the eddy viscosity is chosen to be a function of R(sub y) = (k(sup 1/2)y)/v instead of y(+). Hence, the model could be used for flows with separation. The model constants used are the same as in the high Reynolds number standard k-epsilon model. Thus, the proposed model will be also suitable for flows far from the wall. Turbulent channel flows at different Reynolds numbers and turbulent boundary layer flows with and without pressure gradient are calculated. Results show that the model predictions are in good agreement with direct numerical simulation and experimental data. Yang, Z. and Shih, T. H. Glenn Research Center NASA ORDER C-99066-6; RTOP 505-62-21...
Download or read book A New Time Scale Based K e Model for Near Wall Turbulence written by Z. Yang and published by . This book was released on 1992 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Near wall Turbulent Flows written by Ronald M. C. So and published by Elsevier Publishing Company. This book was released on 1993 with total page 1072 pages. Available in PDF, EPUB and Kindle. Book excerpt: Knowledge of near-wall turbulence from experimental, theoretical and numerical sources is accumulating at an ever increasing rate. An overview of the latest important developments is reported and discussed in depth in this volume with the goal of stimulating closer dialogue between researchers in all areas of near-wall turbulence. The full text of 95 contributed papers cover a broad range of topics in near-wall turbulent flows that includes boundary layers, coherent structures, drag reduction, experimental methods, high speed flows, numerical simulations, transition and turbulent modeling. The innovativeness of the contributions demonstrates that near-wall turbulence remains a vital and dynamically evolving field with important technological consequences for the future.
Download or read book Turbulence Models and Their Application written by Tuncer Cebeci and published by Springer Science & Business Media. This book was released on 2003-12-04 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: After a brief review of the more popular turbulence models, the author presents and discusses accurate and efficient numerical methods for solving the boundary-layer equations with turbulence models based on algebraic formulas (mixing length, eddy viscosity) or partial-differential transport equations. A computer program employing the Cebeci-Smith model and the k-e model for obtaining the solution of two-dimensional incompressible turbulent flows without separation is discussed in detail and is presented in the accompanying CD.
Download or read book Workshop on Computational Turbulence Modeling written by and published by . This book was released on 1994 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improved Turbulence Models Based on Large Eddy Simulation of Homogeneous Incompressible Turbulent Flows written by Stanford University. Thermosciences Division. Thermosciences Division and published by . This book was released on 1983 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The physical bases of large eddy simulation and the subgrid scale modeling it employs are studied in some detail. This investigation leads to a new scale-similarity model for the subgrid-scale turbulent Reynolds stresses.
Download or read book A Galilean and Tensorial Invariant K e Model for Near Wall Turbulence written by Z. Yang and published by . This book was released on 1993 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence Modeling for CFD CD ROM written by David C. Wilcox and published by . This book was released on 2006 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A First Course in Turbulence written by Henk Tennekes and published by MIT Press. This book was released on 2018-04-27 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book specifically designed to offer the student a smooth transitionary course between elementary fluid dynamics (which gives only last-minute attention to turbulence) and the professional literature on turbulent flow, where an advanced viewpoint is assumed. The subject of turbulence, the most forbidding in fluid dynamics, has usually proved treacherous to the beginner, caught in the whirls and eddies of its nonlinearities and statistical imponderables. This is the first book specifically designed to offer the student a smooth transitionary course between elementary fluid dynamics (which gives only last-minute attention to turbulence) and the professional literature on turbulent flow, where an advanced viewpoint is assumed. Moreover, the text has been developed for students, engineers, and scientists with different technical backgrounds and interests. Almost all flows, natural and man-made, are turbulent. Thus the subject is the concern of geophysical and environmental scientists (in dealing with atmospheric jet streams, ocean currents, and the flow of rivers, for example), of astrophysicists (in studying the photospheres of the sun and stars or mapping gaseous nebulae), and of engineers (in calculating pipe flows, jets, or wakes). Many such examples are discussed in the book. The approach taken avoids the difficulties of advanced mathematical development on the one side and the morass of experimental detail and empirical data on the other. As a result of following its midstream course, the text gives the student a physical understanding of the subject and deepens his intuitive insight into those problems that cannot now be rigorously solved. In particular, dimensional analysis is used extensively in dealing with those problems whose exact solution is mathematically elusive. Dimensional reasoning, scale arguments, and similarity rules are introduced at the beginning and are applied throughout. A discussion of Reynolds stress and the kinetic theory of gases provides the contrast needed to put mixing-length theory into proper perspective: the authors present a thorough comparison between the mixing-length models and dimensional analysis of shear flows. This is followed by an extensive treatment of vorticity dynamics, including vortex stretching and vorticity budgets. Two chapters are devoted to boundary-free shear flows and well-bounded turbulent shear flows. The examples presented include wakes, jets, shear layers, thermal plumes, atmospheric boundary layers, pipe and channel flow, and boundary layers in pressure gradients. The spatial structure of turbulent flow has been the subject of analysis in the book up to this point, at which a compact but thorough introduction to statistical methods is given. This prepares the reader to understand the stochastic and spectral structure of turbulence. The remainder of the book consists of applications of the statistical approach to the study of turbulent transport (including diffusion and mixing) and turbulent spectra.
Download or read book Multiscale and Multiresolution Approaches in Turbulence written by Pierre Sagaut and published by World Scientific. This book was released on 2013 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Turbulent Flows written by G. Biswas and published by CRC Press. This book was released on 2002 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Large Eddy Simulations of Turbulence written by M. Lesieur and published by Cambridge University Press. This book was released on 2005-08-22 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large-Eddy Simulations of Turbulence is a reference for LES, direct numerical simulation and Reynolds-averaged Navier-Stokes simulation.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1973 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Methods in Heat Transfer written by Roland Wynne Lewis and published by John Wiley & Sons. This book was released on 1981 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Boundary Layer Theory written by Hermann Schlichting (Deceased) and published by Springer. This book was released on 2016-10-04 with total page 814 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition of the near-legendary textbook by Schlichting and revised by Gersten presents a comprehensive overview of boundary-layer theory and its application to all areas of fluid mechanics, with particular emphasis on the flow past bodies (e.g. aircraft aerodynamics). The new edition features an updated reference list and over 100 additional changes throughout the book, reflecting the latest advances on the subject.
Download or read book Mathematics of Large Eddy Simulation of Turbulent Flows written by Luigi Carlo Berselli and published by Springer Science & Business Media. This book was released on 2006 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: The LES-method is rapidly developing in many practical applications in engineering The mathematical background is presented here for the first time in book form by one of the leaders in the field
