Fundamentals Of Turbulence Modelling

Author: Ching Jen Chen
Publisher: CRC Press
ISBN: 9781560324058
Format: PDF, ePub, Mobi
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Focuses on the second-order turbulence-closure model and its applications to engineering problems. Topics include turbulent motion and the averaging process, near-wall turbulence, applications of turbulence models, and turbulent buoyant flows.

Advances in Fluid Modeling Turbulence Measurements

Author: Akira Wada
Publisher: World Scientific
ISBN: 9789812777591
Format: PDF, Mobi
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This book is an essential reference for engineers and scientists working in the field of turbulence. It covers a variety of applications, such as: turbulence measurements; mathematical and numerical modeling of turbulence; thermal hydraulics; applications for civil, mechanical and nuclear engineering; environmental fluid mechanics; river and open channel flows; coastal problems; ground water.

Statistical Mechanics of Turbulent Flows

Author: Stefan Heinz
Publisher: Springer Science & Business Media
ISBN: 3662100223
Format: PDF, ePub
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The simulation of technological and environmental flows is very important for many industrial developments. A major challenge related to their modeling is to involve the characteristic turbulence that appears in most of these flows. The traditional way to tackle this question is to use deterministic equations where the effects of turbulence are directly parametrized, i. e. , assumed as functions of the variables considered. However, this approach often becomes problematic, in particular if reacting flows have to be simulated. In many cases, it turns out that appropriate approximations for the closure of deterministic equations are simply unavailable. The alternative to the traditional way of modeling turbulence is to construct stochastic models which explain the random nature of turbulence. The application of such models is very attractive: one can overcome the closure problems that are inherent to deterministic methods on the basis of relatively simple and physically consistent models. Thus, from a general point of view, the use of stochastic methods for turbulence simulations seems to be the optimal way to solve most of the problems related to industrial flow simulations. However, it turns out that this is not as simple as it looks at first glance. The first question concerns the numerical solution of stochastic equations for flows of environmental and technological interest. To calculate industrial flows, 3 one often has to consider a number of grid cells that is of the order of 100 .

Process Modelling and Simulation in Chemical Biochemical and Environmental Engineering

Author: Ashok Kumar Verma
Publisher: CRC Press
ISBN: 1482205920
Format: PDF, ePub, Mobi
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The use of simulation plays a vital part in developing an integrated approach to process design. By helping save time and money before the actual trial of a concept, this practice can assist with troubleshooting, design, control, revamping, and more. Process Modelling and Simulation in Chemical, Biochemical and Environmental Engineering explores effective modeling and simulation approaches for solving equations. Using a systematic treatment of model development and simulation studies for chemical, biochemical, and environmental processes, this book explains the simplification of a complicated process at various levels with the help of a "model sketch." It introduces several types of models, examines how they are developed, and provides examples from a wide range of applications. This includes the simple models based on simple laws such as Fick’s law, models that consist of generalized equations such as equations of motion, discrete-event models and stochastic models (which consider at least one variable as a discrete variable), and models based on population balance. Divided into 11 chapters, this book: Presents a systematic approach of model development in view of the simulation need Includes modeling techniques to model hydrodynamics, mass and heat transfer, and reactors for single as well as multi-phase systems Provides stochastic and population balance models Covers the application and development of artificial neural network models and hybrid ANN models Highlights gradients based techniques as well as statistical techniques for model validation and sensitivity analysis Contains examples on development of analytical, stochastic, numerical, and ANN-based models and simulation studies using them Illustrates modeling concepts with a wide spectrum of classical as well as recent research papers Process Modelling and Simulation in Chemical, Biochemical and Environmental Engineering includes recent trends in modeling and simulation, e.g. artificial neural network (ANN)-based models, and hybrid models. It contains a chapter on flowsheeting and batch processes using commercial/open source software for simulation.

Computational Fluid Dynamics

Author: Paul D. Bates
Publisher: John Wiley & Sons
ISBN: 9780470843598
Format: PDF
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With the adoption by environmental scientists of CFD models, there is a need for a book outlining CFD theory in a manner relevant to environmental applications that is accessible to those who have not done mathematics or physics as a first degree.

Numerical Modelling of Hydrodynamics for Water Resources

Author: Pilar Garcia Navarro
Publisher: CRC Press
ISBN: 1482288516
Format: PDF, Kindle
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Overland flow modelling has been an active field of research for some years, but developments in numerical methods and computational resources have recently accelerated progress, producing models for different geometries and types of flows, such as simulations of canal and river networks. Flow in canals has traditionally been described using one-dimensional, depth-averaged, shallow water models; but a variety of simulation techniques now facilitate the management of hydrodynamic systems, providing models which incorporate complex geometry and diverse flows. Much effort has gone into elaborating canal operational rules based on decision support systems, with the dual aim of assuring water delivery and meeting flow control constraints. In natural water courses, water management problems are associated with the need to meet quality standards. Numerical modelling of advection-diffusion can be used to manage problems related to the movement of solutes in rivers and aquifers. The analysis of solute transport is used to safeguard the quality of surface and ground water and to help prevent eutrophication. Solute flow through the soil can be dynamically linked to overland flow for hydrological and agricultural applications. Advances in modelling also cast new light on sediment transport in rivers, exploring the complex dynamics of river bed erosion and deposition and assist in thee analysis of river-reservoir systems. All these issues are discussed in Numerical Modelling of Hydrodynamics for Water Resources, which will be useful to civil engineers, applied mathematicians, hydrologists, and physicists.

Engineering Turbulence Modelling and Experiments 5

Author: W. Rodi
Publisher: Elsevier
ISBN: 9780080530949
Format: PDF, Mobi
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Turbulence is one of the key issues in tackling engineering flow problems. As powerful computers and accurate numerical methods are now available for solving the flow equations, and since engineering applications nearly always involve turbulence effects, the reliability of CFD analysis depends increasingly on the performance of the turbulence models. This series of symposia provides a forum for presenting and discussing new developments in the area of turbulence modelling and measurements, with particular emphasis on engineering-related problems. The papers in this set of proceedings were presented at the 5th International Symposium on Engineering Turbulence Modelling and Measurements in September 2002. They look at a variety of areas, including: Turbulence modelling; Direct and large-eddy simulations; Applications of turbulence models; Experimental studies; Transition; Turbulence control; Aerodynamic flow; Aero-acoustics; Turbomachinery flows; Heat transfer; Combustion systems; Two-phase flows. These papers are preceded by a section containing 6 invited papers covering various aspects of turbulence modelling and simulation as well as their practical application, combustion modelling and particle-image velocimetry.

Statistical Turbulence Modelling for Fluid Dynamics Demystified

Author: Michael Leschziner
Publisher: World Scientific
ISBN: 1783266635
Format: PDF, ePub
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This book is intended for self-study or as a companion of lectures delivered to post-graduate students on the subject of the computational prediction of complex turbulent flows. There are several books in the extensive literature on turbulence that deal, in statistical terms, with the phenomenon itself, as well its many manifestations in the context of fluid dynamics. Statistical Turbulence Modelling for Fluid Dynamics — Demystified differs from these and focuses on the physical interpretation of a broad range of mathematical models used to represent the time-averaged effects of turbulence in computational prediction schemes for fluid flow and related transport processes in engineering and the natural environment. It dispenses with complex mathematical manipulations and instead gives physical and phenomenological explanations. This approach allows students to gain a 'feel' for the physical fabric represented by the mathematical structure that describes the effects of turbulence and the models embedded in most of the software currently used in practical fluid-flow predictions, thus counteracting the ill-informed black-box approach to turbulence modelling. This is done by taking readers through the physical arguments underpinning exact concepts, the rationale of approximations of processes that cannot be retained in their exact form, and essential calibration steps to which the resulting models are subjected by reference to theoretically established behaviour of, and experimental data for, key canonical flows. Contents: Statistical Viewpoint of Turbulence — Motivation and RationaleWhat Makes Turbulence Tick?Reynolds-AveragingFundamentals of Stress / Strain InteractionFundamentals of Near-Wall InteractionsFundamentals of Scalar-Flux / Scalar-Gradient InteractionsThe Eddy ViscosityOne-Equation Eddy-Viscosity ModelsTwo-Equation ModelsWall Functions For Linear Eddy-Viscosity ModelsDefects of Linear Eddy-Viscosity Models, Their Sources and (Imperfect) Corrections Reynolds-Stress-Transport ModellingScalar/Heat-Flux-Ttransport ModellingThe ¯υ2 — ƒ ModelAlgebraic Reynolds-Stress and Non-Linear Eddy-Viscosity Models Readership: Researchers and post-graduate students in the field of fluid dynamics. Key Features:Emphasis on physical and phenomenological interpretationBroad range of models coveredStrong emphasis on understanding the concepts and the rationale behind assumptionsAvoidance of mathematical complexity that does not serve the objective of conveying understanding and insightKeywords:Turbulence Modeling;Rans;Computational Fluid Dynamics;Single Point Closure