Detailed and Reduced Kinetic Mechanisms in Low-emission Combustion Processes

Detailed and Reduced Kinetic Mechanisms in Low-emission Combustion Processes PDF Author: Sylvie Honnet
Publisher: Cuvillier Verlag
ISBN: 386727391X
Category :
Languages : en
Pages : 147

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Detailed and Reduced Kinetic Mechanisms in Low-emission Combustion Processes

Detailed and Reduced Kinetic Mechanisms in Low-emission Combustion Processes PDF Author: Sylvie Honnet
Publisher: Cuvillier Verlag
ISBN: 386727391X
Category :
Languages : en
Pages : 147

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Book Description


Reduced Kinetic Mechanisms for Applications in Combustion Systems

Reduced Kinetic Mechanisms for Applications in Combustion Systems PDF Author: Norbert Peters
Publisher: Springer Science & Business Media
ISBN: 3540475435
Category : Science
Languages : en
Pages : 364

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Book Description
In general, combustion is a spatially three-dimensional, highly complex physi co-chemical process oftransient nature. Models are therefore needed that sim to such a degree that it becomes amenable plify a given combustion problem to theoretical or numerical analysis but that are not so restrictive as to distort the underlying physics or chemistry. In particular, in view of worldwide efforts to conserve energy and to control pollutant formation, models of combustion chemistry are needed that are sufficiently accurate to allow confident predic tions of flame structures. Reduced kinetic mechanisms, which are the topic of the present book, represent such combustion-chemistry models. Historically combustion chemistry was first described as a global one-step reaction in which fuel and oxidizer react to form a single product. Even when detailed mechanisms ofelementary reactions became available, empirical one step kinetic approximations were needed in order to make problems amenable to theoretical analysis. This situation began to change inthe early 1970s when computing facilities became more powerful and more widely available, thereby facilitating numerical analysis of relatively simple combustion problems, typi cally steady one-dimensional flames, with moderately detailed mechanisms of elementary reactions. However, even on the fastest and most powerful com puters available today, numerical simulations of, say, laminar, steady, three dimensional reacting flows with reasonably detailed and hence realistic ki netic mechanisms of elementary reactions are not possible.

Low-temperature Combustion and Autoignition

Low-temperature Combustion and Autoignition PDF Author: M.J. Pilling
Publisher: Elsevier
ISBN: 0080535658
Category : Science
Languages : en
Pages : 823

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Book Description
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.

Key Factors of Combustion

Key Factors of Combustion PDF Author: Nikolai M. Rubtsov
Publisher: Springer
ISBN: 331945997X
Category : Science
Languages : en
Pages : 250

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Book Description
This book summarizes the main advances in the mechanisms of combustion processes. It focuses on the analysis of kinetic mechanisms of gas combustion processes and experimental investigation into the interrelation of kinetics and gas dynamics in gas combustion. The book is complimentary to the one previously published, The Modes of Gaseous Combustion.

Fundamentals of Low Emission Flameless Combustion and Its Applications

Fundamentals of Low Emission Flameless Combustion and Its Applications PDF Author: Seyed Ehsan Hosseini
Publisher: Elsevier
ISBN: 0323852440
Category : Science
Languages : en
Pages : 666

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Book Description
Fundamentals of Low Emission Flameless Combustion and Its Applications is a comprehensive reference on the flameless combustion mode and its industrial applications, considering various types of fossil and alternative fuel. Several experimental and numerical accomplishments on the fundamentals of state-of-the-art flameless combustion is presented, working to clarify the environmentally friendly aspects of this combustion mode. Author Dr. Hosseini presents the latest progresses in the field and highlights the most important achievements since invention, including the fundamentals of thermodynamics, heat transfer and chemical kinetics. Also analyzed is fuel consumption reduction and the efficiency of the system, emissions formation and the effect of the flameless mode on emission reduction. This book provides a solid foundation for those in industry employing flameless combustion for energy conservation and the mitigation of pollutant emissions. It will provide engineers and researchers in energy system engineering, chemical engineering, industrial engineers and environmental engineering with a reliable resource on flameless combustion and may also serve as a textbook for senior graduate students. Presents the fundamentals of flameless combustion and covers advances since its invention Includes experimental and numerical investigations of flameless combustion Analyzes emission formation and highlights the effects of the flameless mode on emission reduction

MILD Combustion: Modelling Challenges, Experimental Configurations and Diagnostic Tools

MILD Combustion: Modelling Challenges, Experimental Configurations and Diagnostic Tools PDF Author: Alessandro Parente
Publisher: Frontiers Media SA
ISBN: 2889717003
Category : Technology & Engineering
Languages : en
Pages : 160

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Book Description


Effect of Chemical Kinetic Mechanisms on Turbulent Combustion

Effect of Chemical Kinetic Mechanisms on Turbulent Combustion PDF Author: Salvador Badillo-Rios
Publisher:
ISBN:
Category :
Languages : en
Pages : 116

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Book Description
Understanding the effects of alternative chemical kinetic mechanisms in turbulent reactive flows is critical to the ability to accurately simulate combustion processes, especially in practical systems. Exploring such effects is not a trivial endeavor because turbulent reactive simulations can be costly, especially when Direct Numerical Simulations (DNS) are employed and/or for large parameter studies. In addition, detailed chemical kinetic mechanisms are often too large and impractical for incorporation in multi-dimensional transient flow field simulations. The large number of species and reactions, as well as the wide range of time scales, in the detailed chemical kinetics account for the computational cost in largescale combustion simulations. Currently, reduced mechanisms are developed under specific laminar flow conditions in which selected global properties of a flame (e.g., ignition delay time, laminar flame speed, adiabatic flame temperature) are matched to those of the original detailed mechanism. However, this imposes restrictions on the operating range and applicability of these reduced mechanisms. For example, in addition to the presence of turbulence, it cannot be guaranteed that these specific conditions will be met everywhere in the flowfield for non-premixed combustion. If turbulence is shown to affect the results from reduced models, then use of the model would become flow and regime specific. It may even be necessary to simulate each flow configuration with detailed chemical kinetic mechanisms before reduced models can be developed for that flow configuration. A better understanding of the sensitivities of turbulent reactive flow results is clearly needed to address these issues. The Chemical Explosive Mode Analysis (CEMA) appears to be an efficient computational diagnostic tool that may give insight into the the important species and reactions in a given flowfield, and to help to explain differences that various kinetic mechanisms may produce in a reactive flowfield. Thus, CEMA may have the potential to help in the development of reduced mechanisms. The objective of this dissertation is to gain insights into the influence of alternative chemical kinetics mechanisms on the results of turbulent combustion simulations and, specifically, the effects of these mechanisms under conditions representative of rocket injector applications. Methane-oxygen combustion simulations of a shear coaxial injection configuration are performed using several chemical kinetic mechanisms ranging from detailed, to skeletal, to reduced mechanisms. Multi-dimensional simulations of rocket injector flowfields are used to establish the underlying issues and motivate the studies. 0D and 1D simulations in concert with the the Chemical Explosive Mode Analysis (CEMA) procedure are then employed to develop insight into the important species and reactions involved to explain differences between the different kinetic mechanisms. Injector results reveal that it is important to establish grid convergence before making comparisons of reaction mechanisms. They also show that the skeletal FFCM1-21 chemical mechanism has time-step and spatial grid sensitivity compared to the detailed GRI-Mech 3.0 mechanism. Given that FFCM1-21 is a skeletal mechanism, the absence of certain species may be responsible for the sensitivity. The CEMA module is first validated with published hydrogen-air 1D premixed flame results. The CEMA method is then applied to a 0D homogeneous combustion problem to obtain insights about the important species and reactions in methane-oxygen combustion for various chemistry models relevant to the rocket injector problem described earlier. A gaseous methane-oxygen mixture is studied as well as mixtures with the addition of H and/or O radicals to simulate the effects of turbulent mixing of burnt gases with reactants. For these cases, a new detailed mechanism (FFCM-1) and a reduced version (FFCMY-12) are used to study the underlying sensitivities. It is found that there is poor prediction of the ignition delay by the reduced mechanism FFCMY-12 in the presence of radicals as compared with the full FFCM-1 mechanism. Trends seen in 0D results help to identify the important species and reactions necessary for a reduced mechanism to replicate important phenomena such as ignition. Because of this, there is confidence that 0D simulations with the CEMA implementation could also help in pinpointing the pertinent species and reactions and in identifying and determining what to examine in a large and more complex turbulent dataset.

Mathematical Modelling of Gas-Phase Complex Reaction Systems: Pyrolysis and Combustion

Mathematical Modelling of Gas-Phase Complex Reaction Systems: Pyrolysis and Combustion PDF Author:
Publisher: Elsevier
ISBN: 0128195797
Category : Technology & Engineering
Languages : en
Pages : 1034

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Book Description
Mathematical Modelling of Gas-Phase Complex Reaction Systems: Pyrolysis and Combustion, Volume 45, gives an overview of the different steps involved in the development and application of detailed kinetic mechanisms, mainly relating to pyrolysis and combustion processes. The book is divided into two parts that cover the chemistry and kinetic models and then the numerical and statistical methods. It offers a comprehensive coverage of the theory and tools needed, along with the steps necessary for practical and industrial applications. Details thermochemical properties and "ab initio" calculations of elementary reaction rates Details kinetic mechanisms of pyrolysis and combustion processes Explains experimental data for improving reaction models and for kinetic mechanisms assessment Describes surrogate fuels and molecular reconstruction of hydrocarbon liquid mixtures Describes pollutant formation in combustion systems Solves and validates the kinetic mechanisms using numerical and statistical methods Outlines optimal design of industrial burners and optimization and dynamic control of pyrolysis furnaces Outlines large eddy simulation of turbulent reacting flows

Detailed and Reduced Chemical-kinetic Descriptions for Hydrocarbon Combustion

Detailed and Reduced Chemical-kinetic Descriptions for Hydrocarbon Combustion PDF Author: Maria V. Petrova
Publisher:
ISBN:
Category :
Languages : en
Pages : 266

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Book Description


Cleaner Combustion

Cleaner Combustion PDF Author: Frédérique Battin-Leclerc
Publisher: Springer Science & Business Media
ISBN: 1447153073
Category : Technology & Engineering
Languages : en
Pages : 657

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Book Description
This overview compiles the on-going research in Europe to enlarge and deepen the understanding of the reaction mechanisms and pathways associated with the combustion of an increased range of fuels. Focus is given to the formation of a large number of hazardous minor pollutants and the inability of current combustion models to predict the formation of minor products such as alkenes, dienes, aromatics, aldehydes and soot nano-particles which have a deleterious impact on both the environment and on human health. Cleaner Combustion describes, at a fundamental level, the reactive chemistry of minor pollutants within extensively validated detailed mechanisms for traditional fuels, but also innovative surrogates, describing the complex chemistry of new environmentally important bio-fuels. Divided into five sections, a broad yet detailed coverage of related research is provided. Beginning with the development of detailed kinetic mechanisms, chapters go on to explore techniques to obtain reliable experimental data, soot and polycyclic aromatic hydrocarbons, mechanism reduction and uncertainty analysis, and elementary reactions. This comprehensive coverage of current research provides a solid foundation for researchers, managers, policy makers and industry operators working in or developing this innovative and globally relevant field.