Chemical Kinetics in Combustion and Reactive Flows: Modeling Tools and Applications PDF Download

Author: V. I. Naoumov
Publisher: Cambridge University Press
ISBN: 1108427049
Category : Science
Languages : en
Pages : 449

View

Book Description
Introduces advanced mathematical tools for the modeling, simulation, and analysis of chemical non-equilibrium phenomena in combustion and flows, following a detailed explanation of the basics of thermodynamics and chemical kinetics of reactive mixtures. Researchers, practitioners, lecturers, and graduate students will find this work valuable.

Author: Roger Prud'homme
Publisher: Springer Science & Business Media
ISBN: 0817646590
Category : Technology & Engineering
Languages : en
Pages : 492

View

Book Description
The modeling of reactive flows has progressed mainly with advances in aerospace, which gave birth to a new science called aerothermochemistry, as well as through developments in chemical and process engineering. This work examines basic concepts and methods necessary to study reactive flows and transfer phenomena in areas such as fluid mechanics, thermodynamics, and chemistry. The book presents tools of interest to graduate students, researchers in mathematical physics, and engineers who wish to investigate problems of reactive flows. Portions of the text may be used in courses on the physics of liquids or in seminars on mechanics.

Author: Robert J. Kee
Publisher: John Wiley & Sons
ISBN: 047146130X
Category : Science
Languages : en
Pages : 884

View

Book Description
Complex chemically reacting flow simulations are commonly employed to develop quantitative understanding and to optimize reaction conditions in systems such as combustion, catalysis, chemical vapor deposition, and other chemical processes. Although reaction conditions, geometries, and fluid flow can vary widely among the applications of chemically reacting flows, all applications share a need for accurate, detailed descriptions of the chemical kinetics occurring in the gas-phase or on reactive surfaces. Chemically Reacting Flow: Theory and Practice combines fundamental concepts in fluid mechanics and physical chemistry, assisting the student and practicing researcher in developing analytical and simulation skills that are useful and extendable for solving real-world engineering problems. The first several chapters introduce transport processes, primarily from a fluid-mechanics point of view, incorporating computational simulation from the outset. The middle section targets physical chemistry topics that are required to develop chemically reacting flow simulations, such as chemical thermodynamics, molecular transport, chemical rate theories, and reaction mechanisms. The final chapters deal with complex chemically reacting flow simulations, emphasizing combustion and materials processing. Among other features, Chemically Reacting Flow: Theory and Practice: -Advances a comprehensive approach to interweaving the fundamentals of chemical kinetics and fluid mechanics -Embraces computational simulation, equipping the reader with effective, practical tools for solving real-world problems -Emphasizes physical fundamentals, enabling the analyst to understand how reacting flow simulations achieve their results -Provides a valuable resource for scientists and engineers who use Chemkin or similar software Computer simulation of reactive systems is highly effective in the development, enhancement, and optimization of chemical processes. Chemically Reacting Flow helps prepare both students and professionals to take practical advantage of this powerful capability.

Author: Robert J. Kee
Publisher: John Wiley & Sons
ISBN: 1119186285
Category : Science
Languages : en
Pages : 793

View

Book Description
A guide to the theoretical underpinnings and practical applications of chemically reacting flow Chemically Reacting Flow: Theory, Modeling, and Simulation, Second Edition combines fundamental concepts in fluid mechanics and physical chemistry while helping students and professionals to develop the analytical and simulation skills needed to solve real-world engineering problems. The authors clearly explain the theoretical and computational building blocks enabling readers to extend the approaches described to related or entirely new applications. New to this Second Edition are substantially revised and reorganized coverage of topics treated in the first edition. New material in the book includes two important areas of active research: reactive porous-media flows and electrochemical kinetics. These topics create bridges between traditional fluid-flow simulation approaches and transport within porous-media electrochemical systems. The first half of the book is devoted to multicomponent fluid-mechanical fundamentals. In the second half the authors provide the necessary fundamental background needed to couple reaction chemistry into complex reacting-flow models. Coverage of such topics is presented in self-contained chapters, allowing a great deal of flexibility in course curriculum design. • Features new chapters on reactive porous-media flow, electrochemistry, chemical thermodynamics, transport properties, and solving differential equations in MATLAB • Provides the theoretical underpinnings and practical applications of chemically reacting flow • Emphasizes fundamentals, allowing the analyst to understand fundamental theory underlying reacting-flow simulations • Helps readers to acquire greater facility in the derivation and solution of conservation equations in new or unusual circumstances • Reorganized to facilitate use as a class text and now including a solutions manual for academic adopters Computer simulation of reactive systems is highly efficient and cost-effective in the development, enhancement, and optimization of chemical processes. Chemically Reacting Flow: Theory, Modeling, and Simulation, Second Edition helps prepare graduate students in mechanical or chemical engineering, as well as research professionals in those fields take utmost advantage of that powerful capability.

Author: A.L. De Bortoli
Publisher: Elsevier
ISBN: 0128029919
Category : Technology & Engineering
Languages : en
Pages : 212

View

Book Description
Modelling and Simulation of Reactive Flows presents information on modeling and how to numerically solve reactive flows. The book offers a distinctive approach that combines diffusion flames and geochemical flow problems, providing users with a comprehensive resource that bridges the gap for scientists, engineers, and the industry. Specifically, the book looks at the basic concepts related to reaction rates, chemical kinetics, and the development of reduced kinetic mechanisms. It considers the most common methods used in practical situations, along with equations for reactive flows, and various techniques—including flamelet, ILDM, and Redim—for jet flames and plumes, with solutions for both. In addition, the book includes techniques to accelerate the convergence of numerical simulation, and a discussion on the analysis of uncertainties with numerical results, making this a useful reference for anyone who is interested in both combustion in free flow and in porous media. Helps readers learn how to apply applications of numerical methods to simulate geochemical kinetics Presents methods on how to transform the transport equations in several coordinate systems Includes discussions of the basic concepts related to reaction rates, chemical kinetics, and the development of reduced kinetic mechanisms, including the most common methods used in practical situations Offers a distinctive approach that combines diffusion flames and geochemical flow problems

Author: Shuliang Zhang
Publisher:
ISBN:
Category : Biodiesel fuels
Languages : en
Pages : 97

View

Book Description
The primary objective of this research is to characterize fuel combustion in reactive flow simulations using advanced kinetic modeling and mechanism reduction tools. Since incorporating detailed chemical kinetic model in the realistic reactive flow simulations is a computationally challenging task due to the large size of detailed kinetic mechanism, it is of great interest to develop approaches for simplifying the kinetic models and reducing computational costs in reactive flow simulations. In this dissertation, we first extend the previously developed on-the-fly reduction approach to the characterization of complex biodiesel combustion using detailed biodiesel surrogate mechanism. Major combustion characteristics such as ignition, emission, as well as engine performance for biodiesel compared with conventional fossil fuels are studied. Although the incorporation of detailed biodiesel combustion mechanism in complex reactive flow simulation is enabled, the simulation is still highly time-consuming. To further alleviate the computational intensity, a hybrid reduction scheme coupling the on-the-fly reduction with global quasi-steady-state approximation (QSSA) is developed. The proposed hybrid reduction scheme is demonstrated in various reactive flow simulations including zero-dimensional PFR model, multidimensional HCCI engine CFD model, and realistic gas phase injector CFD simulations. A flux-based quasi-steady-state (QSS) species selection procedure is introduced to facilitate the demonstration of hybrid scheme. Finally, a novel computational framework integrating automated mechanism generation and on-the-fly reduction is proposed and implemented using a stepwise integration. The proposed framework is then demonstrated in methane oxidation case studies and shows a new way of conducting reactive flow simulation without having an actual mechanism before the simulation starts. The integration of automated mechanism generation and on-the-fly reduction is a promising technique to perform reactive flow simulations and has the potential to reduce the computational cost of the simulations. The work in this dissertation provides powerful tools and important insight for the incorporation of detailed chemical kinetics in the reactive flow simulations.

Author: Salvador Badillo-Rios
Publisher:
ISBN:
Category :
Languages : en
Pages : 116

View

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.

Author: J. Warnatz
Publisher: Springer Science & Business Media
ISBN: 3662045087
Category : Science
Languages : en
Pages : 309

View

Book Description
This book provides a rigorous treatment of the coupling of chemical reactions and fluid flow. Combustion-specific topics of chemistry and fluid mechanics are considered and tools described for the simulation of combustion processes. This edition is completely restructured. Mathematical Formulae and derivations as well as the space-consuming reaction mechanisms have been replaced from the text to appendix. A new chapter discusses the impact of combustion processes on the atmosphere, the chapter on auto-ignition is extended to combustion in Otto- and Diesel-engines, and the chapters on heterogeneous combustion and on soot formation are heavily revised.

Author: Jürgen Warnatz
Publisher: Springer Science & Business Media
ISBN: 3642980279
Category : Science
Languages : en
Pages : 309

View

Book Description
Combustion is an old technology, which at present provides about 90% of our worldwide energy support. Combustion research in the past used fluid mechanics with global heat release by chemical reactions described with thermodynamics, assuming infinitely fast reactions. This approach was useful for stationary combustion processes, but it is not sufficient for transient processes like ignition and quenching or for pollutant formation. Yet pollutant formation during combustion of fossil fuels is a central topic and will continue to be so in future. This book provides a detailed and rigorous treatment of the coupling of chemical reactions and fluid flow. Also, combustion-specific topics of chemistry and fluid mechanics are considered, and tools described for the simulation of combustion processes. For the 2nd edition, the parts dealing with experiments, spray combustion, and soot were thoroughly revised.

Author: Norbert Peters
Publisher: Springer Science & Business Media
ISBN: 3540475435
Category : Science
Languages : en
Pages : 364

View

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.