Turbulence and Molecular Processes in Combustion

Author: T. Takeno
Publisher: Elsevier
ISBN: 0444598898
Format: PDF, Mobi
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An understanding of the intricacies in the turbulent combustion process may be a key to solving many of the current energy and environmental problems. The essential nature of turbulent combustion can be derived from the interaction between stochastic flow fluctuations and deterministic molecular processes, such as chemical reaction and transport processes. Undoubtedly, this is one of the most challenging fields of engineering science today, requiring as it does the interaction of scientists and engineers in the respective fields of chemical kinetics and fluid mechanics. The 28 papers in this volume review recent advances in these two disciplines providing new insights into the fundamental processes, addressing a great deal of recent progress. This progress ranges from descriptions of elementary chemical kinetics, to working those descriptions into combustion calculations with large numbers of elementary steps, to improved understanding of turbulent reacting flows and advances in simulations of turbulent combustion. The contributions will inspire further research on many fronts, advancing the understanding of combustion processes, as well as fostering a growing interdisciplinary cooperation.

Turbulent Combustion Modeling

Author: Tarek Echekki
Publisher: Springer Science & Business Media
ISBN: 9789400704121
Format: PDF, ePub, Mobi
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Turbulent combustion sits at the interface of two important nonlinear, multiscale phenomena: chemistry and turbulence. Its study is extremely timely in view of the need to develop new combustion technologies in order to address challenges associated with climate change, energy source uncertainty, and air pollution. Despite the fact that modeling of turbulent combustion is a subject that has been researched for a number of years, its complexity implies that key issues are still eluding, and a theoretical description that is accurate enough to make turbulent combustion models rigorous and quantitative for industrial use is still lacking. In this book, prominent experts review most of the available approaches in modeling turbulent combustion, with particular focus on the exploding increase in computational resources that has allowed the simulation of increasingly detailed phenomena. The relevant algorithms are presented, the theoretical methods are explained, and various application examples are given. The book is intended for a relatively broad audience, including seasoned researchers and graduate students in engineering, applied mathematics and computational science, engine designers and computational fluid dynamics (CFD) practitioners, scientists at funding agencies, and anyone wishing to understand the state-of-the-art and the future directions of this scientifically challenging and practically important field.

Fundamentals of Premixed Turbulent Combustion

Author: Andrei Lipatnikov
Publisher: CRC Press
ISBN: 1466510242
Format: PDF, ePub, Docs
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Lean burning of premixed gases is considered to be a promising combustion technology for future clean and highly efficient gas turbine combustors. Yet researchers face several challenges in dealing with premixed turbulent combustion, from its nonlinear multiscale nature and the impact of local phenomena to the multitude of competing models. Filling a gap in the literature, Fundamentals of Premixed Turbulent Combustion introduces the state of the art of premixed turbulent combustion in an accessible manner for newcomers and experienced researchers alike. To more deeply consider current research issues, the book focuses on the physical mechanisms and phenomenology of premixed flames, with a brief discussion of recent advances in partially premixed turbulent combustion. It begins with a summary of the relevant knowledge needed from disciplines such as thermodynamics, chemical kinetics, molecular transport processes, and fluid dynamics. The book then presents experimental data on the general appearance of premixed turbulent flames and details the physical mechanisms that could affect the flame behavior. It also examines the physical and numerical models for predicting the key features of premixed turbulent combustion. Emphasizing critical analysis, the book compares competing concepts and viewpoints with one another and with the available experimental data, outlining the advantages and disadvantages of each approach. In addition, it discusses recent advances and highlights unresolved issues. Written by a leading expert in the field, this book provides a valuable overview of the physics of premixed turbulent combustion. Combining simplicity and topicality, it helps researchers orient themselves in the contemporary literature and guides them in selecting the best research tools for their work.

Fundamentals and Technology of Combustion

Author: F El-Mahallawy
Publisher: Elsevier
ISBN: 9780080532189
Format: PDF, ePub
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Fundamentals and Technology of Combustion contains brief descriptions of combustion fundamental processes, followed by an extensive survey of the combustion research technology. It also includes mathematical combustion modeling of the processes covering mainly premixed and diffusion flames, where many chemical and physical processes compete in complex ways, for both laminar and turbulent flows. The combustion chemistry models that validate experimental data for different fuels are sufficiently accurate to allow confident predictions of the flame characteristics. This illustrates a unique bridge between combustion fundamentals and combustion technology, which provides a valuable technical reference for many engineers and scientists. Moreover, the book gives the reader sufficient background of basic engineering sciences such as chemistry, thermodynamics, heat transfer and fluid mechanics. The combustion research and mathematical models fit between small-scale laboratory burner flames, and large-scale industrial boilers, furnaces and combustion chambers. The materials have been collected from previous relevant research and some selected papers of the authors and co-workers, which have been presented mainly in different refereed journals, international conferences and symposia, thus providing a comprehensive collection. Furthermore, the book includes some of the many recent general correlations for the characteristics of laminar, turbulent, premixed and diffusion flames in an easily usable form. The authors believe that further progress in optimizing combustion performance and reducing polluting emissions can only be treated through understanding of combustion chemistry.

Modeling Engine Spray and Combustion Processes

Author: Gunnar Stiesch
Publisher: Springer Science & Business Media
ISBN: 9783540006824
Format: PDF, ePub, Docs
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The utilization of mathematical models to numerically describe the performance of internal combustion engines is of great significance in the development of new and improved engines. Today, such simulation models can already be viewed as standard tools, and their importance is likely to increase further as available com puter power is expected to increase and the predictive quality of the models is constantly enhanced. This book describes and discusses the most widely used mathematical models for in-cylinder spray and combustion processes, which are the most important subprocesses affecting engine fuel consumption and pollutant emissions. The relevant thermodynamic, fluid dynamic and chemical principles are summarized, and then the application of these principles to the in-cylinder processes is ex plained. Different modeling approaches for the each subprocesses are compared and discussed with respect to the governing model assumptions and simplifica tions. Conclusions are drawn as to which model approach is appropriate for a specific type of problem in the development process of an engine. Hence, this book may serve both as a graduate level textbook for combustion engineering stu dents and as a reference for professionals employed in the field of combustion en gine modeling. The research necessary for this book was carried out during my employment as a postdoctoral scientist at the Institute of Technical Combustion (ITV) at the Uni versity of Hannover, Germany and at the Engine Research Center (ERC) at the University of Wisconsin-Madison, USA.

Turbulent Premixed Flames

Author: Nedunchezhian Swaminathan
Publisher: Cambridge University Press
ISBN: 1139498584
Format: PDF, ePub, Docs
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A work on turbulent premixed combustion is timely because of increased concern about the environmental impact of combustion and the search for new combustion concepts and technologies. An improved understanding of lean fuel turbulent premixed flames must play a central role in the fundamental science of these new concepts. Lean premixed flames have the potential to offer ultra-low emission levels, but they are notoriously susceptible to combustion oscillations. Thus, sophisticated control measures are inevitably required. The editors' intent is to set out the modeling aspects in the field of turbulent premixed combustion. Good progress has been made recently on this topic. Thus, it is timely to edit a cohesive volume containing contributions from international experts on various subtopics of the lean premixed flame problem.

Combustion Science and Engineering

Author: Kalyan Annamalai
Publisher: CRC Press
ISBN: 9780849320712
Format: PDF, ePub, Docs
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Students embarking on their studies in chemical, mechanical, aerospace, energy, and environmental engineering will face continually changing combustion problems, such as pollution control and energy efficiency, throughout their careers. Approaching these challenges requires a deep familiarity with the fundamental theory, mathematics, and physical concepts of combustion. Based on more than two decades of teaching experience, Combustion Science and Engineering lays the necessary groundwork while using an illustrative, hands-on approach. Taking a down-to-earth perspective, the book avoids heavy mathematics in the first seven chapters and in Chapter 17 (pollutants formation and destruction), but considers molecular concepts and delves into engineering details. It begins with an outline of thermodynamics; basics of thermochemistry and chemical equilibrium; descriptions of solid, liquid, and gaseous fuels; chemical kinetics and mass transfer; and applications of theory to practical systems. Beginning in chapter 8, the authors provide a detailed treatment of differential forms of conservation equations; analyses of fuel combustion including jet combustion and boundary layer problems; ignition; flame propagation; interactive and group combustion; pollutant formation and control; and turbulent combustion. In addition, this textbook includes abundant examples, illustrations, and exercises, as well as spreadsheet software in combustion available for download. This software allows students to work out the examples found in the text. Combustion Science and Engineering imparts the skills and foundational knowledge necessary for students to successfully approach and solve new problems.