A New Hypothesis on the Anisotropic Reynolds Stress Tensor for Turbulent Flows
A New Hypothesis on the Anisotropic Reynolds Stress Tensor for Turbulent Flows

Author: László Könözsy

Publisher: Springer Nature

Published: 2020-12-01

Total Pages: 517

ISBN-13: 3030606031

DOWNLOAD EBOOK

This self-contained, interdisciplinary book encompasses mathematics, physics, computer programming, analytical solutions and numerical modelling, industrial computational fluid dynamics (CFD), academic benchmark problems and engineering applications in conjunction with the research field of anisotropic turbulence. It focuses on theoretical approaches, computational examples and numerical simulations to demonstrate the strength of a new hypothesis and anisotropic turbulence modelling approach for academic benchmark problems and industrially relevant engineering applications. This book contains MATLAB codes, and C programming language based User-Defined Function (UDF) codes which can be compiled in the ANSYS-FLUENT environment. The computer codes help to understand and use efficiently a new concept which can also be implemented in any other software packages. The simulation results are compared to classical analytical solutions and experimental data taken from the literature. A particular attention is paid to how to obtain accurate results within a reasonable computational time for wide range of benchmark problems. The provided examples and programming techniques help graduate and postgraduate students, engineers and researchers to further develop their technical skills and knowledge.

A New Hypothesis on the Anisotropic Reynolds Stress Tensor for Turbulent Flows
A New Hypothesis on the Anisotropic Reynolds Stress Tensor for Turbulent Flows

Author: László Könözsy

Publisher: Springer

Published: 2019-02-26

Total Pages: 152

ISBN-13: 3030135438

DOWNLOAD EBOOK

This book gives a mathematical insight--including intermediate derivation steps--into engineering physics and turbulence modeling related to an anisotropic modification to the Boussinesq hypothesis (deformation theory) coupled with the similarity theory of velocity fluctuations. Through mathematical derivations and their explanations, the reader will be able to understand new theoretical concepts quickly, including how to put a new hypothesis on the anisotropic Reynolds stress tensor into engineering practice. The anisotropic modification to the eddy viscosity hypothesis is in the center of research interest, however, the unification of the deformation theory and the anisotropic similarity theory of turbulent velocity fluctuations is still missing from the literature. This book brings a mathematically challenging subject closer to graduate students and researchers who are developing the next generation of anisotropic turbulence models. Indispensable for graduate students, researchers and scientists in fluid mechanics and mechanical engineering.

Theories of Turbulence
Theories of Turbulence

Author: Martin Oberlack

Publisher: Springer

Published: 2014-05-04

Total Pages: 377

ISBN-13: 3709125642

DOWNLOAD EBOOK

The term "turbulence” is used for a large variety of dynamical phenomena of fluids in motion whenever the details of the flow appear to be random and average properties are of primary interest. Just as wide ranging are the theoretical methods that have been applied towards a better understanding of fluid turbulence. In this book a number of these methods are described and applied to a broad range of problems from the transition to turbulence to asymptotic turbulence when the inertial part of the spectrum is fully developed. Statistical as well as nonstatistical treatments are presented, but a complete coverage of the subject is not attempted. The book will be of interest to scientists and engineers who wish to familiarize themselves with modern developments in theories of turbulence. The fact that the properties of turbulent fluid flow are addressed from very different points of view makes this volume rather unique among presently available books on turbulence.

Turbulent Flows
Turbulent Flows

Author: Stephen B. Pope

Publisher: Cambridge University Press

Published: 2000-08-10

Total Pages: 810

ISBN-13: 9780521598866

DOWNLOAD EBOOK

This is a graduate text on turbulent flows, an important topic in fluid dynamics. It is up-to-date, comprehensive, designed for teaching, and is based on a course taught by the author at Cornell University for a number of years. The book consists of two parts followed by a number of appendices. Part I provides a general introduction to turbulent flows, how they behave, how they can be described quantitatively, and the fundamental physical processes involved. Part II is concerned with different approaches for modelling or simulating turbulent flows. The necessary mathematical techniques are presented in the appendices. This book is primarily intended as a graduate level text in turbulent flows for engineering students, but it may also be valuable to students in applied mathematics, physics, oceanography and atmospheric sciences, as well as researchers and practising engineers.

Development of a More General Reynolds Stress Closure for Swirling Flow
Development of a More General Reynolds Stress Closure for Swirling Flow

Author: S. B. Chin

Publisher:

Published: 1988

Total Pages: 16

ISBN-13:

DOWNLOAD EBOOK

This paper is concerned with the modelling of the return to isotropy part of the pressure strain term in homogeneous anisotropic turbulent flows. Analytical solutions of the transport equations of the invariants of the anisotropy tensor as well as that of turbulent kinetic energy as a function of the natural time of decay are provided and discussed. Principal components of the Reynolds stresses are obtained from the solution of a cubic equation which involves the invariants. It is shown that current models based on Rotta's hypothesis are subject to a constraint which is only satisfied by axisymmetric homogeneous turbulence, and the constraint can be eliminated by non-linear modelling. A physical picture of energy transfer among the Reynolds stress components which takes into account the influence of the third invariant on the process of return to isotropy is presented. Keywords: Second order closure; Reynolds stress model; Homogeneous turbulence; Non-linear effects; Swirling flows; Compressible flows.

Mathematical and Physical Theory of Turbulence, Volume 250
Mathematical and Physical Theory of Turbulence, Volume 250

Author: John Cannon

Publisher: CRC Press

Published: 2006-06-15

Total Pages: 209

ISBN-13: 1420014978

DOWNLOAD EBOOK

Although the current dynamical system approach offers several important insights into the turbulence problem, issues still remain that present challenges to conventional methodologies and concepts. These challenges call for the advancement and application of new physical concepts, mathematical modeling, and analysis techniques. Bringing together ex

Recent Research on Environmental Earth Sciences, Geomorphology, Soil Science, Paleoclimate, and Karst
Recent Research on Environmental Earth Sciences, Geomorphology, Soil Science, Paleoclimate, and Karst

Author: Attila Çiner

Publisher: Springer Nature

Published: 2023-12-16

Total Pages: 256

ISBN-13: 3031429176

DOWNLOAD EBOOK

This edited book is based on the accepted papers for presentation at the 1st MedGU Annual Meeting, Istanbul, 2021. With two parts spanning a large spectrum of environmental, geomorphological and geoarcheological topics and a third part on caves and karst, which includes research studies gathered on the occasion of the International Year of Caves and Karst (2021), this book presents a series of newest research studies that are nowadays relevant to Middle East, Mediterranean region, and Africa. The book gives a general overview on current research, focusing on geoenvironmental issues and challenges in environmental management in the Middle East and Mediterranean region and surrounding areas. It offers a broad range of recent studies that discuss the latest advances in geomorphology, landslides, soil science, paleoclimate, and geoarcheology. It also shares insights on cave and karst studies including speleology, cave and karst explorations, geomorphology, hydrogeology, geoethics, prehistoric eras in karst, geotectonics, and the nexus between human activities and karst sustainability.