Kubacki and E. Dick was designed for simulating bypass transition in turbomachinery. A modification of mentioned model was proposed. Modified model is suitable for simulating internal flows in pipes and parallel-plate channels.
Values of several constants of the original model were modified. For selected Reynolds numbers and turbulence intensities Tu , localization of laminar breakdown and fully turbulent flow was presented.
Results obtained in this work were compared with corresponding experimental results available in the literature. It is particularly worth noting that asymptotic values of wall shear stress in flow channels and asymptotic values of axis velocity obtained during simulations are similar to related experimental and theoretical results.
The modified model allows precision numerical simulation in the area of transitional flow between laminar, intermittent and turbulent flows in pipes and parallel-plate channels. David C.
Wilcox, was born in Wilmington, Delaware. He did his undergraduate studies from to at the Massachusetts Institute of Technology, graduating with a Bachelor of Science degree in Aeronautics and Astronautics.
His experience with McDonnell Douglas was primarily in subsonic and transonic flow calculations. From to , he attended the California Institute of Technology, graduating with a Ph. He performed studies of both high- and low-speed fluid-mechanical and heat-transfer problems, such as turbulent hypersonic flow and thermal radiation from a flame. From to , he was a staff scientist for Applied Theory, Inc.
He participated directly in many research efforts involving numerical computation and anal- ysis of a wide range of fluid flows such as separated turbulent flow, tran- sitional flow and hypersonic plume-body interaction.
He has taught several fluid mechanics and applied mathematics courses at the University of Southern California and at the University of California, Los Angeles. Wilcox has published many papers and reports on turbulence mod- eling, computational fluid dynamics, boundary-layer separation, boundary- layer transition, thermal radiation, and rapidly rotating fluids. Contents Notation xi Preface xvii 1 Introduction 1 1. In order to avoid departing too much from conventions normally used in liter- ature on turbulence modeling and general fluid mechanics, a few symbols denote more than one quantity.
While several computational fluid dynamics CFD texts include some information about turbulence modeling, very few texts dealing exclusively with turbulence modeling have been written. As a con- sequence, turbulence modeling is regarded by many CFD researchers as "black magic," lacking in rigor and physical foundation. This book has been written to show that turbulence modeling can be done in a systematic and physically sound manner.
This is not to say all turbulence modeling has been done in such a manner, for indeed many ill-conceived and ill-fated turbulence models have appeared in engineering journals. Even this au- thor, early in his career, devised a turbulence model that violated Galilean invariance of the time-averaged Navier-Stokes equations! However, with judicious use of relatively simple mathematical tools, systematic construc- tion of a well-founded turbulence model is not only possible but can be an exciting and challenging research project.
Thus, the primary goal of this book is to provide a systematic approach to developing a set of constitutive equations suitable for computation of turbulent flows. The engineer who feels no existing turbulence model is suitable for his or her needs and wishes to modify an existing model or to devise a new model will benefit from this feature of the text.
A methodology is presented in Chapters 3 and 4 for devising and testing such equations. The methodology is illustrated in great detail for two-equation turbulence models. However, it is by no means limited to such models and is used again in Chapter 6 for a full Reynolds-stress model, but with less detail. A secondary goal of this book is to provide a rational way for deciding how complex a model is needed for a given problem.
The engineer who wishes to select an existing model that is sufficient for his or her needs will benefit most from this feature of the text. Two things are done at each level of complexity. First, the range of applicability of the model is estimated. Second, many of the applications are repeated for all of the models to illustrate how accuracy changes with complexity. The methodology makes extensive use of tensor analysis, similarity so- lutions, singular perturbation methods, and numerical procedures.
The text assumes the user has limited prior knowledge of these mathemati- cal concepts and provides what is needed both in the main text and in the Appendices. For example, Appendix A introduces rudiments of tensor analysis to facilitate manipulation of the Navier-Stokes equation, which is done extensively in Chapter 2.
This text is an ideal instructional resource and reference for students, research scientists, and professional engineers interested in analyzing fluid flows using numerical simulations for fundamental research and industrial applications. This study reports the development and validation of a modified two-equation eddy-viscosity turbulence model for computational fluid dynamics prediction of transitional and turbulent flows.
This book presents and discussses new developments in the area of turbulence modelling and measurements, with particular emphasis on engineering-related problems. Atmospheric turbulence Posted on Author : David C.
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