Chemical kinetic factors of hydrocarbon oxidation are examined in a variety of ignition problems. Ignition is related to the presence of a dominant chain branching reaction mechanism that can drive a chemical system to completion in a very short period of time. Ignition in laboratory environments is studied for problems including shock tubes and rapid compression machines. Modeling of the laboratory systems are used to develop kinetic models that can be used to analyze ignition in practical systems. Two major chain branching regimes are identified, one consisting of high temperature ignition with a chain branching reaction mechanism based on the reaction between atomic hydrogen with molecular oxygen, and the second based on an intermediate temperature thermal decomposition of hydrogen peroxide. Kinetic models are then used to describe ignition in practical combustion environments, including detonations and pulse combustors for high temperature ignition, and engine knock and diesel ignition for intermediate temperature ignition. The final example of ignition in a practical environment is homogeneous charge, compression ignition (HCCI) which is shown to be a problem dominated by the kinetics intermediate temperature hydrocarbon ignition. Model results show why high hydrocarbon and CO emissions are inevitable in HCCI combustion. The conclusion of this study is that the kinetics of hydrocarbon ignition are actually quite simple, since only one or two elementary reactions are dominant. However, there are many combustion factors that can influence these two major reactions, and these are the features that vary from one practical system to another.

Combustion has played a central role in the development of our civilization which it maintains today as its predominant source of energy. The aim of this book is to provide an understanding of both fundamental and applied aspects of low-temperature combustion chemistry and autoignition. The topic is rooted in classical observational science and has grown, through an increasing understanding of the linkage of the phenomenology to coupled chemical reactions, to quite profound advances in the chemical kinetics of both complex and elementary reactions. The driving force has been both the intrinsic interest of an old and intriguing phenomenon and the centrality of its applications to our economic prosperity. The volume provides a coherent view of the subject while, at the same time, each chapter is self-contained.

My introduction to the fascinating phenomena associated with detonation waves came through appointments as an external fellow at the Department of Physics, University College of Wales, and at the Department of Mechanical Engineering, University of Leeds. Very special thanks for his accurate guidance through the large body of information on gaseous detonations are due to Professor D. H. Edwards of University College of Wales. Indeed, the onerous task of concisely enumerating the key features of unidimensional theories of detonations was undertaken by him, and Chapter 2 is based on his initial draft. When the text strays to the use of we, it is a deserved acknow ledgement of his contribution. Again, I should like to thank Professor D. Bradley of Leeds University for his enthusiastic encouragement of my efforts at developing a model of the composition limits of detonability through a relationship between run-up distance and composition of the mixture. The text has been prepared in the context of these fellowships, and I am grateful to the Central Electricity Generating Board for its permission to accept these appointments.

The present program aimed to study ignition in nonhomogeneous systems that are of relevance to practical combustion devices. The investigation was conducted in both laminar and turbulent environments, and involved experimental, computational, and analytical components. For turbulent ignition, four specific projects were undertaking, namely: (1)Characterization of non-reacting turbulent flow fields in counterflow; (2)turbulent non-premixed ignition experiments; (3)modeling study of turbulent nonpremixed ignition; (4)computational simulation of the ignition of an nonpremixed hydrogen/air mixing layer with an embedded vortex. In parallel, three projects in laminar premixed and nonpremixed counterflow were explored, especially focusing on the chemical kinetics aspects and the coupling with transport, namely: (1) Premixed hydrogen/air and propane/air ignition; (2) experimental determination and computational calculation of the counterflow ignition temperatures and laminar flame speeds of several C2-C3 hydrocarbons; (3) experimental determination and computational calculation of the ignition temperatures of nonpremixed counterflow dimethyl ether (DME) versus air.

Throughout its previous four editions, Combustion has made a very complex subject both enjoyable and understandable to its student readers and a pleasure for instructors to teach. With its clearly articulated physical and chemical processes of flame combustion and smooth, logical transitions to engineering applications, this new edition continues that tradition. Greatly expanded end-of-chapter problem sets and new areas of combustion engineering applications make it even easier for students to grasp the significance of combustion to a wide range of engineering practice, from transportation to energy generation to environmental impacts. Combustion engineering is the study of rapid energy and mass transfer usually through the common physical phenomena of flame oxidation. It covers the physics and chemistry of this process and the engineering applications—including power generation in internal combustion automobile engines and gas turbine engines. Renewed concerns about energy efficiency and fuel costs, along with continued concerns over toxic and particulate emissions, make this a crucial area of engineering. - New chapter on new combustion concepts and technologies, including discussion on nanotechnology as related to combustion, as well as microgravity combustion, microcombustion, and catalytic combustion—all interrelated and discussed by considering scaling issues (e.g., length and time scales) - New information on sensitivity analysis of reaction mechanisms and generation and application of reduced mechanisms - Expanded coverage of turbulent reactive flows to better illustrate real-world applications - Important new sections on stabilization of diffusion flames—for the first time, the concept of triple flames will be introduced and discussed in the context of diffusion flame stabilization