Author : Daniel Tat-Leung Wong
Publisher :
Page : 72 pages
File Size : 27,64 MB
Release : 1994
Category : Turbulent boundary layer
ISBN :
Author : Manuel D. Salas
Publisher : Springer Science & Business Media
Page : 385 pages
File Size : 43,34 MB
Release : 2012-12-06
Category : Science
ISBN : 9401147248
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.
Author : Tuncer Cebeci
Publisher :
Page : 42 pages
File Size : 45,42 MB
Release : 1977
Category : Laminar flow
ISBN :
Author : Tuncer Cebeci
Publisher :
Page : 502 pages
File Size : 30,96 MB
Release : 2005
Category : Hydraulic engineering
ISBN : 9780966846195
This second edition of the book, Modeling and Computation of Boundary Layer Flows, extends the topic to include compressible flows including the energy equation and non-constant fluid properties in the continuity and momentum equations. The necessary additions are included in new chapters, leaving the first nine chapters to serve as an introduction to incompressible flows that can be used as an introduction to computational fluid dynamics with emphasis on the solution of the boundary-layer equations and the modeling and computation of boundary-layer flows. It also provides readers with a good understanding of the basic principles of fluid dynamics and numerical methods. A variety of readers, including undergraduate and graduate students, teachers or scientists working in aerodynamics or hydrodynamics will find the text interesting. The subjects covered in this book include laminar and, turbulent boundary layers and laminar--turbulent transition. The viscous--inviscid coupling between the boundary layer and the inviscid flow is also addressed. Two-dimensional and three-dimensional incompressible flows are considered. Physical and numerical aspects of boundary-layer flows are described in detail and a large number of homework problems are included. The book is accompanied by computer programs to solve boundary layer equations, the Orr-Sommerfeld equation and to compute transitions. Those programs can be used for classroom work but also for industry applications. Additional programs for three-dimensional flows are available from the first author. TOC:Introduction.- Conservation Equations for Mass and Momentum for Incompressible Flows.- Boundary-Layer Equations for Incompressible Flows.- Two-Dimensional Incompressible Laminar Flows.- Transition in Two-Dimensional Incompressible Flows.- Two-Dimensional Incompressible Turbulent Flows.- Three-Dimensional Incompressible Laminar and Turbulent Flows.- Transition in Three-Dimensional Incompressible Flows.- Interactive Boundary-Layer Theory.- Conservation Equations for Mass, Momentum and Energy.- Two-Dimensional Compressible Laminar Flows.- Two-Dimensional Compressible Turbulent Flows.- An Interactive Boundary-Layer Method for Three-Dimensional Flows.- Transition in Three-Dimensional Compressible Flows
Author : Y. Y. Chan
Publisher : 1970.
Page : 42 pages
File Size : 36,61 MB
Release : 1970
Category :
ISBN :
A computational method for turbulent boundary layers in an incompressible two-dimensional flow was formulated. The governing differential equations for the mean flow are solved by an implicit finite differential equations for the mean flow are solved by an implicit finite difference method. The Reynolds shear stress is correlated by Prandtl's mixing length concept. Four models of correlation for the mixing length are studied and prediction based on these models is assessed by comparison with several sets of experimental data. It is found that models correlated only to local mean flow cannot adjust themselves to the proper turbulent state for highly non-equilibrium flow. If the turbulent state is considered explicitly by computing the mixing length from the turbulent energy equation, the results show excellent agreement with experimental data. This model is thus recommended for practical uses. (Author).
Author : Tuncer Cebeci
Publisher : Elsevier
Page : 423 pages
File Size : 28,62 MB
Release : 2012-12-02
Category : Technology & Engineering
ISBN : 0323151051
Analysis of Turbulent Boundary Layers focuses on turbulent flows meeting the requirements for the boundary-layer or thin-shear-layer approximations. Its approach is devising relatively fundamental, and often subtle, empirical engineering correlations, which are then introduced into various forms of describing equations for final solution. After introducing the topic on turbulence, the book examines the conservation equations for compressible turbulent flows, boundary-layer equations, and general behavior of turbulent boundary layers. The latter chapters describe the CS method for calculating two-dimensional and axisymmetric laminar and turbulent boundary layers. This book will be useful to readers who have advanced knowledge in fluid mechanics, especially to engineers who study the important problems of design.
Author : Tuncer Cebeci
Publisher : Springer
Page : 502 pages
File Size : 17,74 MB
Release : 2005-05-04
Category : Science
ISBN : 9783540244592
This second edition of the book, Modeling and Computation of Boundary-Layer Flows^ extends the topic to include compressible flows. This implies the inclusion of the energy equation and non-constant fluid properties in the continuity and momentum equations. The necessary additions are included in new chapters, leaving the first nine chapters to serve as an introduction to incompressible flows and, therefore, as a platform for the extension. This part of the book can be used for a one semester course as described below. Improvements to the incompressible flows portion of the book include the removal of listings of computer programs and their description, and their incor poration in two CD-ROMs. A listing of the topics incorporated in the CD-ROM is provided before the index. In Chapter 7 there is a more extended discussion of initial conditions for three-dimensional flows, application of the characteristic box to a model problem and discussion of flow separation in three-dimensional laminar flows. There are also changes to Chapter 8, which now includes new sections on Tollmien-Schlichting and cross-flow instabilities and on the predic tion of transition with parabolised stability equations, and Chapter 9 provides a description of the rational behind interactive boundary-layer procedures.
Author :
Publisher :
Page : 32 pages
File Size : 30,88 MB
Release : 1982
Category :
ISBN :
Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 32 pages
File Size : 37,90 MB
Release : 2018-08-13
Category :
ISBN : 9781725140189
Incompressible three dimensional, turbulent boundary layer (3DTBL) experiments were simulated numerically by integrating the boundary layer equations together with an algebraic eddy viscosity turbulence model. For the flow treated, the downstream portion, where the crossflow was large, was not predicted with the present computational method; the flow was significantly influenced by elliptic flow field effects. Departures from the boundary layer concept are indicated. Calculations agreed reasonably well with the mean flow development up to separation. In one experiment the normal pressure gradients were found to be neligible in regions with large skewing and allowed testing turbulence models using the boundary layer equations. The simulation of this flow compared favorably with the experimental data throughout the flow field and suggested the applicability of algebraic eddy viscosity models for 3DTBLs. Mueller, U. R. Ames Research Center NASA-TM-84230, A-8873, NAS 1.15:84230 ...
Author : Jean Potvin
Publisher : World Scientific
Page : 274 pages
File Size : 20,89 MB
Release : 1994-06-09
Category :
ISBN : 981455099X
The proceedings contain the invited papers delivered at the 2nd IMACS International Conference on Computational Physics, held in St. Louis MO, USA, on October 6 - 9, 1993. The meeting was aimed at bringing together computational scientists and engineers of different disciplines for a fruitful exchange of information on methods, software and hardware. The topics covered include fluid mechanics, aerodynamics, material physics, condensed matter physics, neural networks, nonlinear dynamics, particle physics and others.
