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
The combustion of fossil fuels remains a key technology for the foreseeable future. It is therefore important that we understand the mechanisms of combustion and, in particular, the role of turbulence within this process. Combustion always takes place within a turbulent flow field for two reasons: turbulence increases the mixing process and enhances combustion, but at the same time combustion releases heat which generates flow instability through buoyancy, thus enhancing the transition to turbulence. The four chapters of this book present a thorough introduction to the field of turbulent combustion. After an overview of modeling approaches, the three remaining chapters consider the three distinct cases of premixed, non-premixed, and partially premixed combustion, respectively. This book will be of value to researchers and students of engineering and applied mathematics by demonstrating the current theories of turbulent combustion within a unified presentation of the field.
A work on turbulent premixed combustion is important 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 on this topic, and this cohesive volume contains contributions from international experts on various subtopics of the lean premixed flame problem.
The articles in this volume treat various problems in combustion science that are of importance in applications to technology and to environmental sciences. The authors treat turbulence in premixed and non-premixed flames as well as pressure interactions and wave phenomena. Also supersonic flows and detonations are discussed. The main emphasis, however, is on the modelling and numerical treatment of combustion phenomena. The book addresses researchers in physics and engineering, and mathematicians from scientific computing.
The International Workshop on Turbulent Combustion was held September 14-15, 2000, at the Nagoya Institute of Technology, to review the present status of turbu lent combustion studies. Reviews were presented by Prof. F. A. Williams of the Uni versity of California, San Diego; Prof. Ken Bray of the University of Cambridge; and Prof. Jay Gore of Purdue University. Dr. Howard Baum of the National Institute of Standards and Technology and Dr. Jim McDonough of the University of Ken tucky participated in the discussion. Some ten papers, describing the latest findings of Japanese studies in this field, were given at the meeting. About half of these studies are supported by a national project, the Open and Integrated Research Pro gram, Creation of New Functionalized Thermo-Fluid Systems by Turbulence Con trol, that started only recently under the sponsorship of the Science and Technology Agency of Japan. The meeting was a great success and gave impetus and a sense of perspective to young Japanese researchers through the excellent reviews and valu able comments their work received. I believe that this kind of open discussion is indispensable for any project to produce a good outcome, and I would like to extend my sincere thanks to all who participated in the meeting. Finally, I would like to express my special thanks to Prof. Tatsuya Hasegawa of the Nagoya Institute of Technology, Prof. Akira Yoshida of Tokyo Denki University, Prof.
The research has been concerned with two topics in premixed turbulent combustion. One relates to a continuation of the research on the discovery of new mechanisms for turbulent transport and turbulence generation arising from the interaction of mean force fields due to gradients of either pressure or shear stresses and density variations. These earlier studies consider infinite planar flames and since the mechanisms in question are confined to the flames themselves, the question arises as to their applied significance and importance in determining global features of turbulent flows consisting of two regions of uniform density on each side of a flame. To examine this question we have extended the analysis to provide a unified theory for the description of all three regions. The second topics relates to the consideration of the length and time scales of the temperature field in a premixed turbulent flame. The time history of the temperature at a point within such a flame involves alternately high and low values corresponsing respectively to the passage of products and reactants. By appropriate normalization such a history can be made into a telegraph signal whose statistical characteristics provide information on the time scales of the temperature field. We have shown that an analysis of these characteristics leads to a model for an important quantity in the phenomenology of premixed turbulent combustion, namely the mean rate of chemical reaction.
Detailed coverage of advanced combustion topics from the author of Principles of combustion, Second Edition Turbulence, turbulent combustion, and multiphase reacting flows have become major research topics in recent decades due to their application across diverse fields, including energy, environment, propulsion, transportation, industrial safety, and nanotechnology. Most of the knowledge accumulated from this research has never been published in book form—until now. Fundamentals of Turbulent and Multiphase Combustion presents up-to-date, integrated coverage of the fundamentals of turbulence, combustion, and multiphase phenomena along with useful experimental techniques, including non-intrusive, laser-based measurement techniques, providing a firm background in both contemporary and classical approaches. Beginning with two full chapters on laminar premixed and non-premixed flames, this book takes a multiphase approach, beginning with more common topics and moving on to higher-level applications. In addition, Fundamentals of Turbulent and Multiphase Combustion: Addresses seven basic topical areas in combustion and multiphase flows, including laminar premixed and non-premixed flames, theory of turbulence, turbulent premixed and non-premixed flames, and multiphase flows Covers spray atomization and combustion, solid-propellant combustion, homogeneous propellants, nitramines, reacting boundary-layer flows, single energetic particle combustion, and granular bed combustion Provides experimental setups and results whenever appropriate Supported with a large number of examples and problems as well as a solutions manual, Fundamentals of Turbulent and Multiphase Combustion is an important resource for professional engineers and researchers as well as graduate students in mechanical, chemical, and aerospace engineering.
This book presents a comprehensive review of state-of-the-art models for turbulent combustion, with special emphasis on the theory, development and applications of combustion models in practical combustion systems. It simplifies the complex multi-scale and nonlinear interaction between chemistry and turbulence to allow a broader audience to understand the modeling and numerical simulations of turbulent combustion, which remains at the forefront of research due to its industrial relevance. Further, the book provides a holistic view by covering a diverse range of basic and advanced topics—from the fundamentals of turbulence–chemistry interactions, role of high-performance computing in combustion simulations, and optimization and reduction techniques for chemical kinetics, to state-of-the-art modeling strategies for turbulent premixed and nonpremixed combustion and their applications in engineering contexts.
