Download or read book Sensitivity Analysis of Laminar Premixed CH 4 air Flames Using Full and Reduced Kinetic Mechanisms written by Bernd Rogg and published by . This book was released on 1990 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reduced Kinetic Mechanisms and Asymptotic Approximations for Methane Air Flames written by Mitchell D. Smooke and published by Springer. This book was released on 2014-03-12 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this comprehensive text a systematic numerical and analytical treatment of the procedures for reducing complicated systems to a simplified reaction mechanism is presented. The results of applying the reduced reaction mechanism to a one-dimensional laminar flame are discussed. A set of premixed and non-premixed methane-air flames with simplified transport and skeletal chemistry are employed as test problems that are used later on to evaluate the results and assumptions in reduced reaction networks. The first four chapters form a short tutorial on the procedures used in formulating the test problems and in reducing reaction mechanisms by applying steady-state and partial-equilibrium approximations. The final six chapters discuss various aspects of the reduced chemistry problem for premixed and nonpremixed combustion.
Download or read book Reduced Kinetic Mechanisms and Asymptotic Approximations for Methane air Flames written by Mitchell D. Smooke and published by Springer. This book was released on 1991 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this comprehensive text a systematic numerical and analytical treatment of the procedures for reducing complicated systems to a simplified reaction mechanism is presented. The results of applying the reduced reaction mechanism to a one-dimensional laminar flame are discussed. A set of premixed and non-premixed methane-air flames with simplified transport and skeletal chemistry are employed as test problems that are used later on to evaluate the results and assumptions in reduced reaction networks. The first four chapters form a short tutorial on the procedures used in formulating the test problems and in reducing reaction mechanisms by applying steady-state and partial-equilibrium approximations. The final six chapters discuss various aspects of the reduced chemistry problem for premixed and nonpremixed combustion.
Download or read book Reduced Kinetic Mechanisms for Applications in Combustion Systems written by Norbert Peters and published by Springer Science & Business Media. This book was released on 2008-09-11 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book An Experimental and Computational Study on the Propagation and Kinetic Structure of Laminar Premixed Flames written by Fokion Egolfopoulos and published by . This book was released on 1990 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Premixed Flames written by Nedunchezhian Swaminathan and published by Cambridge University Press. This book was released on 2011-04-25 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Kinetic Mechanisms for Premixed Laminar Steady State Methane Air Flames written by T. P. Coffee and published by . This book was released on 1983 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: A number of kinetic schemes have been used to model premixed, laminar, one-dimensional methane/air flames. Seven such kinetic schemes, including two new models, are compared with one another and with experimental data. The two new models, one with 14 species and one with 20 species, both agree with the experimental data over a range of stoichiometries from lean to rich. All of the models show good agreement for lean to slightly rich flames. This does not validate any of the models, even for this limited range. Rather, it is shown that the quantities measured are fairly insensitive to much of the mechanism. Therefore, models with incorrect kinetics can agree with the experimental data. In particular, the contribution of the C2 species to methane combustion is examined. While these species are important, we conclude that there is insufficient data to determine quantitatively the effects of the C2 chemistry reactions.
Download or read book Turbulent Combustion written by Norbert Peters and published by Cambridge University Press. This book was released on 2000-08-15 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Mathematical Modeling in Combustion and Related Topics written by Claude-Michel Brauner and published by Springer Science & Business Media. This book was released on 1988-03-31 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains invited lectures and contributed papers presented at the NATO Advanced Research Workshop on Mathematical Modeling in Combustion and related topics, held in. Lyon (France), April 27 - 30, 1987. This conference was planned to fit in with the two-month visit of Professor G.S.S. Ludford to the Ecole Centrale de Lyon. He kindly agreed to chair the Scientific and Organizing Committee and actively helped to initiate the meeting. His death in December 1986 is an enormous loss to the scientific community in general, and in particular, to the people involved in the present enterprise. The subject of mathematical modeling in combustion is too large for a single conference, and the selection of topics re flects both areas of recent research activity and areas of in terest to Professor G.S.S. Ludford, to whose memory the Advanced Workshop and this present volume are dedicated. The meeting was divided into seven specialized sessions detonation theory, mathematical analysis, numerical treatment of combustion problems, flame theory, experimental and industrial aspects, complex chemistry, and turbulent combustion. It brought together researchers and engineers from University and Industry (see below the closing remarks of the workshop by Prof. N. Peters). The articles in this volume have been judged and accepted on their scientific quality, and language corrections may have been sacrificed in order to allow quick dissemination of knowledge to prevail.
Download or read book Physical and Chemical Process in Flames written by and published by . This book was released on 2006 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of the present program are to develop detailed and simplified chemical kinetics models for hydrocarbon combustion, and to understand and quantify the dynamics of flames. During the reporting period progress were made in the following projects: (1) Skeletal reduction using sensitivity analysis aided by directed relation graph; (2) derivation of analytical solution of quasi-steady state species using directed graph; (3) derivation of a reduced mechanism for lean premixed methane/air flames; (4) extinction and stability analyses of diffusion flames with radiation heat loss; and (5) study of the response of premixed flames to velocity fluctuations with flame stretch effects.
Download or read book Developments In High Speed Vehicle Propulsion Systems written by S. N. B. Murthy and published by AIAA. This book was released on 1996 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation There have been impressive achievements in the last few years in the technologies associated with turboramjets and other combined cycle engines. These technologies, including their thermal management and integration with the vehicle, are the principal concerns of this volume. Drawing on the expertise of international engineers and researchers in the field of high-speed vehicle propulsion systems, these articles, written by experts from the United States, Russia, Germany, Japan, Belgium, and Israel, highlight developments in the industry.
Download or read book Combustion Technology for a Clean Environment written by Maria Carvalho and published by CRC Press. This book was released on 2002-11-08 with total page 1576 pages. Available in PDF, EPUB and Kindle. Book excerpt: The more than 90 refereed papers in this volume continue a series of biannual benchmarks for technologies that maximize energy conversion while minimizing undesirable emissions. Covering the entire range of industrial and transport combustion as well as strategies for energy research and development, these state-of-the-art will be indispensable to mechanical and chemical engineers in academia and industry and technical personnel in military, energy and environmental government agencies. The topics covered in this book include wood, oil, gas and coal combustion, combustion of alternative fuels, co-combustion and co-gasification, catalytic combustion, NO, SO, soot fundamentals, advanced diagnostics, burners, fluidized bed combustion, incineration, engines, advanced cycles, gas clean-up, control strategy and clean combustion in process industries.
Download or read book Numerical Analysis of Carbon Monoxide Flames by Reduced Kinetic and Asymptotic Methods written by Maria Lynn Jason Rightley and published by . This book was released on 1996 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reduced Kinetic Mechanisms for Premixed Laminar Flames written by Weigang Wang and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Chemical Kinetic Mechanisms on Turbulent Combustion written by Salvador Badillo-Rios and published by . This book was released on 2020 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book MILD Combustion Modelling Challenges Experimental Configurations and Diagnostic Tools written by Alessandro Parente and published by Frontiers Media SA. This book was released on 2021-11-26 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Soot Formation in Combustion written by Henning Bockhorn and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 595 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soot Formation in Combustion represents an up-to-date overview. The contributions trace back to the 1991 Heidelberg symposium entitled "Mechanism and Models of Soot Formation" and have all been reedited by Prof. Bockhorn in close contact with the original authors. The book gives an easy introduction to the field for newcomers, and provides detailed treatments for the specialists. The following list of contents illustrates the topics under review:
