Download or read book KINETIC MODELING OF FUEL EFFECTS OVER A WIDE RANGE OF CHEMISTRY PROPERTIES AND SOURCES written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Kinetic modeling is an important tool for engine design and can also be used for engine tuning and to study response to fuel chemistry and properties before an engine configuration is physically built and tested. Methodologies needed for studying fuel effects include development of fuel kinetic mechanisms for pure compounds, tools for designing surrogate blends of pure compounds that mimic a desired market fuel, and tools for reducing kinetic mechanisms to a size that allows inclusion in complex CFD engine models. In this paper, we demonstrate the use of these tools to reproduce engine results for a series of research diesel fuels using surrogate fuels in an engine and then modeling results with a simple 2 component surrogate blend with physical properties adjusted to vary fuel volatility. Results indicate that we were reasonably successful in mimicking engine performance of real fuels with blends of pure compounds. We were also successful in spanning the range of the experimental data using CFD and kinetic modeling, but further tuning and matching will be needed to exactly match engine performance of the real and surrogate fuels.

Download or read book Global Chemical Kinetics of Fossil Fuels written by Alan K. Burnham and published by Springer. This book was released on 2017-02-11 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the origin and chemical structure of sedimentary organic matter, how that structure relates to appropriate chemical reaction models, how to obtain reaction data uncontaminated by heat and mass transfer, and how to convert that data into global kinetic models that extrapolate over wide temperature ranges. It also shows applications for in-situ and above-ground processing of oil shale, coal and other heavy fossil fuels. It is essential reading for anyone who wants to develop and apply reliable chemical kinetic models for natural petroleum formation and fossil fuel processing and is designed for course use in petroleum systems modelling. Problem sets, examples and case studies are included to aid in teaching and learning. It presents original work and contains an extensive reanalysis of data from the literature.

Download or read book Chemical Kinetic Modeling of Jet Fuel Surrogates written by Krithika Narayanaswamy and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Jet fuels, like typical transportation fuels, are mixtures of several hundreds of compounds belonging to different hydrocarbon classes. Their composition varies from one source to another, and only average fuel properties are known at best. In order to understand the combustion characteristics of the real fuels, and to address the problem of combustion control, computational studies using a detailed kinetic model to represent the real fuel, serves as a highly useful tool. However, the complexity of the real fuels makes it infeasible to simulate their combustion characteristics directly, requiring a simplified fuel representation to circumvent this difficulty. Typically, the real fuels are modeled using a representative surrogate mixture, i.e. a well-defined mixture comprised of a few components chosen to mimic the desired physical and chemical properties of the real fuel under consideration. Surrogates have been proposed for transportation fuels, including aviation fuels, and several kinetic modeling attempts for the proposed surrogates have also been made. However, (i) the fundamental kinetics of individual fuels, which make up the surrogate mixtures is not understood well, (ii) their combustion behavior at low through high temperatures has not been comprehensively validated, and this directly impacts the (iii) reliability of the multi-component reaction mechanism for a surrogate made up of these individual components. The present work is aimed at addressing the afore-mentioned concerns. The objective of this work is to develop a single, reliable kinetic model that can describe the oxidation of a few representative fuels, which are important components of transportation fuel surrogates, and thereby capture the specificities of the simpler, but still multi-component surrogates. The reaction mechanism is intended to well-represent the individual components as well as a multi-component surrogate for jet fuel made up of these fuel components. Further, this reaction mechanism is desired to be applicable at low through high temperatures, and be compact enough that chemical kinetic analysis is feasible. First, a representative compound for each of the major hydrocarbon classes found in the real jet fuel is identified. A surrogate for jet fuels is chosen to be comprised of n-dodecane (to represent normal alkanes), methylcyclohexane (to represent cyclic alkanes), and m-xylene (to represent aromatics). A Component Library approach is invoked for the development of a single, consistent, and reliable chemical scheme to accurately model this multi-component surrogate mixture. The chemical model is assembled in stages, starting with a base model and adding to it sub-mechanisms for the individual components of the surrogate, namely m- xylene, n-dodecane, and methylcyclohexane. The chemical model is validated comprehensively every time the oxidation pathways of a new component are incorporated into it and the experimental data is well captured by the simulations. In addition to the jet fuel surrogate, with the number of fuels described in the proposed reaction mechanism, a surrogate for the alternative Fischer-Tropsch fuels is also considered. Surrogates are defined for jet fuels and Fischer-Tropsch fuels by matching target properties important for combustion applications between the surrogate and the real fuel. The simulations performed using the proposed reaction mechanism, with the surrogates defined as fuels, are compared against global targets, such as ignition delays, flow reactor profiles, and flame speed measurements for representative jet fuels and Fischer-Tropsch fuels. The computations show promising agreement with these experimental data sets. The proposed reaction mechanism is well-suited to be used in real flow simulations of jet fuels. The proposed reaction mechanism has the ability to describe the kinetics of n- heptane, iso-octane, substituted aromatics, n-dodecane, and methylcyclohexane, all of which are important components of transportation fuel surrogates. Considering the large number of hydrocarbons whose kinetics are well described by this reaction mechanism, there are avenues for this reaction mechanism to be used to model other transportation fuels, such as gasoline, diesel, and alternative fuels, in addition to the jet and Fischer-Tropsch fuels discussed in the present study.

Download or read book Cleaner Combustion written by Frédérique Battin-Leclerc and published by Springer Science & Business Media. This book was released on 2013-09-06 with total page 657 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Chemical Kinetic Modeling of Component Mixtures Relevant to Gasoline written by and published by . This book was released on 2008 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed kinetic models of pyrolysis and combustion of hydrocarbon fuels are nowadays widely used in the design of internal combustion engines and these models are effectively applied to help meet the increasingly stringent environmental and energetic standards. In previous studies by the combustion community, such models not only contributed to the understanding of pure component combustion, but also provided a deeper insight into the combustion behavior of complex mixtures. One of the major challenges in this field is now the definition and the development of appropriate surrogate models able to mimic the actual features of real fuels. Real fuels are complex mixtures of thousands of hydrocarbon compounds including linear and branched paraffins, naphthenes, olefins and aromatics. Their behavior can be effectively reproduced by simpler fuel surrogates containing a limited number of components. Aside the most commonly used surrogates containing iso-octane and n-heptane only, the so called Primary Reference Fuels (PRF), new mixtures have recently been suggested to extend the reference components in surrogate mixtures to also include alkenes and aromatics. It is generally agreed that, including representative species for all the main classes of hydrocarbons which can be found in real fuels, it is possible to reproduce very effectively in a wide range of operating conditions not just the auto-ignition propensity of gasoline or Diesel fuels, but also their physical properties and their combustion residuals [1]. In this work, the combustion behavior of several components relevant to gasoline surrogate formulation is computationally examined. The attention is focused on the autoignition of iso-octane, hexene and their mixtures. Some important issues relevant to the experimental and modeling investigation of such fuels are discussed with the help of rapid compression machine data and calculations. Following the model validation, the behavior of mixtures is discussed on the basis of computational results.

Download or read book Sustainable Automotive Technologies 2012 written by Aleksandar Subic and published by Springer Science & Business Media. This book was released on 2012-03-02 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book on Sustainable Automotive Technologies aims to draw special attention to the research and practice focused on new technologies and approaches capable of meeting the challenges to sustainable mobility. In particular, the book features incremental and radical technical advancements that are able to meet social, economic and environmental targets in both local and global contexts. These include original solutions to the problems of pollution and congestion, vehicle and public safety, sustainable vehicle design and manufacture, new structures and materials, new power-train technologies and vehicle concepts. In addition to vehicle technologies, the book is also concerned with the broader systemic issues such as sustainable supply chain systems, integrated logistics and telematics, and end-of-life vehicle management. It captures selected peer reviewed papers accepted for presentation at the 4th International Conference on Sustainable Automotive Technologies, ICSAT2012, held at the RMIT, Melbourne, Australia.

Download or read book HyChem A Physics based Approach to Modeling Real fuel Combustion Chemistry written by Rui Xu (Mechanical engineer) and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Real fuels usually contain hundreds to thousands of hydrocarbon components. Over a wide range of combustion conditions, large hydrocarbon molecules undergo thermal decomposition first to form a small set (usually less than 10 species) of low molecular weight products, followed by the oxidation of those products, which is usually rate limiting. Hence, the composition of the decomposed products determines the overall global combustion properties. For conventional distillate fuels, the pyrolysis products comprise ethylene (C2H4), hydrogen (H2), methane (CH4), propene (C3H6), 1-butene (1-C4H8), iso-butene (i-C4H8), benzene (C6H6) and toluene (C7H8). From a joint consideration of thermodynamics and chemical kinetics, it is shown that the composition of the thermal decomposition products is a weak function of the thermodynamic condition, the equivalence ratio and the fuel composition within the range of temperatures relevant to high temperature combustion phenomena. In this dissertation study, I demonstrate a hybrid chemistry (HyChem) approach to modeling the high-temperature oxidation of real, liquid fuels. In this approach, the kinetics of fuel pyrolysis is modeled using experimentally derived, lumped reaction steps, while the oxidation of the pyrolysis fragments is described by a detailed foundational fuel chemistry model. A wide range of modeling results are provided to support the approach, including three conventional aviation fuels (JP-8 POSF10264, Jet A POSF10325, JP-5 POSF10289), two rocket fuels (RP2-1 POSF7688, RP2-2 POSF5433), and a bio-derived alternative jet fuel (Gevo alcohol-to-jet fuel, C1 POSF11498). The HyChem models of those fuels were developed using advanced speciation data obtained from shock tubes and a flow reactor, and the models were subsequently tested against global combustion properties, including ignition delay time, laminar flame speed, and flame extinction strain rates across a wide range of pressure, temperature and reactant mixture conditions. Sensitivity analysis of the model predictions with respect to the measurement uncertainties and rate parameter uncertainties of foundational fuel chemistry model is assessed. In this dissertation, the HyChem modeling approach was also extended to three key aspects critical to modeling fuel combustion over an even wider range of condition. First, a modified HyChem model was formulated for capturing the physics in negative temperature coefficient (NTC) and low-temperature oxidation regimes. Sensitivity test and suggestions on future NTC enabled HyChem model development are presented. Second, the HyChem approach was applied to modeling the blend of a conventional Jet A fuel and an alternative, alcohol-to-jet synthetic fuel. The pyrolysis as well as the combustion properties of several blended fuels were predicted by a simple combination of the HyChem models of the two individual fuels, thus demonstrating that the HyChem models for two jet fuels of very different compositions can be "additive" as far as high-temperature properties are concerned. Lastly, I will discuss a case study in which the HyChem model of Jet A is extended to NOx prediction after combining it with a recently updated reaction model of nitrogen chemistry. The combined reaction model is shown to predict NOx formation in premixed stretched-stabilized Jet A flames satisfactorily.

Download or read book Mathematical Modelling of Gas Phase Complex Reaction Systems Pyrolysis and Combustion written by and published by Elsevier. This book was released on 2019-06-21 with total page 1034 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Methanol Synthesis written by Jerzy Skrzypek and published by . This book was released on 1994 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Detailed Chemical Kinetic Model for Oxygenated Fuels written by Sung-Woo Park and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed chemical kinetic model is developed and tested for the combustion of C2 and C3 oxygenated fuels such as ethanol, DME (dimethyl ether), acetone and n-propanol. It is validated by comparing predictions with experimental data on the structure of low pressure burner stabilised premixed flames and laminar burning velocities over a wide range of equivalence ratios. Data from shock tube and stirred reactor studies has also been considered. The elementary reactions of ethanol and DME oxidation have been studied extensively and were used as a starting point for extension to C3 oxygenated fuels. The chemistry of acetylene which is one of major intermediate species in higher hydrocarbon flames was also updated to improve the reliability of the present mechanism and acetylene laminar burning velocities and low-pressure premixed lean and rich flames were also computed. The detailed mechanism features more than 1500 reaction steps and 269 species. The structure of laminar premixed flames are predicted by using measured temperature profiles and conditions cover fuel-lean and fuel-rich mixtures at low pressure. The profiles of reactants, products and major intermediate species are compared to experimental data from mass spectrometry and the overall agreement between the kinetic model and experimental data is satisfactory. An analytic study of fuel consumption pathways is carried out to understand the detailed consumption pathways. The present mechanism is also tested against laminar flame speeds by calculating freely propagating premixed flames to extend the understanding of the combustion characteristics of oxygenated fuels. A sensitivity analysis is also performed.

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 Analysis of Kinetic Reaction Mechanisms written by Tamás Turányi and published by Springer. This book was released on 2014-12-29 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical processes in many fields of science and technology, including combustion, atmospheric chemistry, environmental modelling, process engineering, and systems biology, can be described by detailed reaction mechanisms consisting of numerous reaction steps. This book describes methods for the analysis of reaction mechanisms that are applicable in all these fields. Topics addressed include: how sensitivity and uncertainty analyses allow the calculation of the overall uncertainty of simulation results and the identification of the most important input parameters, the ways in which mechanisms can be reduced without losing important kinetic and dynamic detail, and the application of reduced models for more accurate engineering optimizations. This monograph is invaluable for researchers and engineers dealing with detailed reaction mechanisms, but is also useful for graduate students of related courses in chemistry, mechanical engineering, energy and environmental science and biology.

Download or read book Gas Phase Combustion Chemistry written by W.C., Jr. Gardiner and published by Springer Science & Business Media. This book was released on 1999-12-10 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superseding Gardiner's "Combustion Chemistry", this is an updated, comprehensive coverage of those aspects of combustion chemistry relevant to gas-phase combustion of hydrocarbons. The book includes an extended discussion of air pollutant chemistry and aspects of combustion, and reviews elementary reactions of nitrogen, sulfur and chlorine compounds that are relevant to combustion. Methods of combustion modeling and rate coefficient estimation are presented, as well as access to databases for combustion thermochemistry and modeling.

Download or read book A Study of Strained Extinction for Applications in Natural Gas Combustion Modeling written by Alan Everett Long and published by . This book was released on 2020 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resistance to extinction by stretch is a key property of any flame, and recent work has shown that this property controls the overall structure of several important methane, the principal component of natural gas, based turbulent flames. This work gives an introduction to the parameter that quantifies resistance to extinction by stretch, Extinction Strain Rate (ESR), discussing how it is typically measured experimentally and calculated numerically. The primary limitations of ESR, given its historical definition and computation methods, are: (1) it depends on the dimensions of the experimental apparatus used to measure it, (2) it is often too computationally difficult to calculate using large kinetic models, #species > 500, and (3) under elevated pressures relevant to gas turbines and internal combustion engines, 20-40 atm, it is difficult to measure. Work addressing, in some manner, these three issues is presented. Subsequent work then uses ESR as a validation parameter for producing a kinetic model. To address the first issue, a method is proposed for translating experimental measurements for stretch-induced extinction into an unambiguous and apparatus-independent quantity (ESR[subscript infinity]) by extrapolating to infinite opposing burner separation distance. The uniqueness of the flame at extinction is shown numerically and supported experimentally for twin premixed, single premixed, and diffusion flames at Lewis numbers greater than and less than one. A method for deriving ESR[subscript infinity] from finite-boundary experimental studies is proposed and demonstrated for methane and propane diffusion and premixed single flame data. The values agree within the range of differences typically observed between experimental measurements and simulation results for the traditional ESR definition. To address issue two, Ember, a new open-source code for efficiently performing ESR[subscript infinity] calculations using large, detailed chemical kinetic models is presented. Ember outperforms other standard software, such as Chemkin, in computation time by leveraging rebalanced Strang operator splitting which does not suffer the steady-state inaccuracies of most splitting methods. Ember is then able to improve computational performance primarily though parallelization and use of quasi-steady-state kinetics integrations at each independent spatial discretization point. Ember is validated for computation of ESR and the benefits of its computation techniques are demonstrated. With respect to the third issue, Ember is used to explore ESR[subscript infinity] pressure trends and kinetic model sensitivities in the current absence of experimental methods to probe the relevant parameter space. ESR shows opposing trends with pressure under lean and rich conditions for methane-air flames. Ultimately, ESR decreases at higher pressures for lean conditions ([phi] = 0.7) and increases with pressure for rich conditions ([phi] = 1.3). Under both conditions, the ESR trends are non-monotonic. ESR reaction sensitivities are observed to generally mirror those of laminar flame speed calculations. This suggests that there is limited added value in more efficient methods of ESR reaction sensitivity calculation since efficient adjoint methods already exist for laminar flame speed. Strong species transport parameter sensitivities are observed for the fuel, oxidizer, and bath gas, with the limiting reactant showing the strongest sensitivity. Current levels of uncertainty in species enthalpy suggest little impact of enthalpy errors on ESR predictions for the conditions studied. Using the prior ESR improvements and analysis, an ESR validated kinetic model is produced. The model uses a validation data set that includes relevant ignition delay, laminar flame speed, and extinction strain rate data. The work builds off recent works by Hashemi and coworkers for high pressure oxidation of small hydrocarbons. Prediction of the selected validation data set is improved primarily through sensitivity analysis and comparison with kinetic rate constants from other works. Additionally, to support nitrogen chemistry predictions, the full nitrogen subset from the recent review by Glarborg and coworkers is appended to the core model produced. The Reaction Mechanism Generator (RMG) software has recently been used to generate the rich chemistry relevant for partial oxidation of methane up to one and two ring aromatics. This rich chemistry subset is added to produce the final kinetic model. An important portion of the rich chemistry included within the produced kinetic model is the route from cyclopentadienenyl radical recombination to naphthalene. Since this work seeks performance at elevated pressures of relevance to gas turbines and internal combustion engines, the pathway is re-computed here with explicit consideration of all relevant pressure dependent pathways on the C10H10 and C110H9 surfaces. Lumped, single-step kinetics, often used to describe the net reaction to naphthalene, are observed to be insufficient. Specifically, the C10H10 intermediate species is observed to live long enough to undergo bimolecular reaction to enter the C10H9 surface before proceeding on to naphthalene. Rate expressions for the full network are produced and included in the kinetic model generated.

Download or read book Fundamental Gas phase and Surface Chemistry of Vapor phase Deposition II and Process Control Diagnostics and Modeling in Semiconductor Manufacturing IV written by Electrochemical Society. High Temperature Materials Division and published by The Electrochemical Society. This book was released on 2001 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fossil Energy Update written by and published by . This book was released on 1981 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Detailed Kinetic Modeling of Gasoline Surrogate Mixtures written by and published by . This book was released on 2009 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real fuels are complex mixtures of thousands of hydrocarbon compounds including linear and branched paraffins, naphthenes, olefins and aromatics. It is generally agreed that their behavior can be effectively reproduced by simpler fuel surrogates containing a limited number of components. In this work, a recently revised version of the kinetic model by the authors is used to analyze the combustion behavior of several components relevant to gasoline surrogate formulation. Particular attention is devoted to linear and branched saturated hydrocarbons (PRF mixtures), olefins (1-hexene) and aromatics (toluene). Model predictions for pure components, binary mixtures and multi-component gasoline surrogates are compared with recent experimental information collected in rapid compression machine, shock tube and jet stirred reactors covering a wide range of conditions pertinent to internal combustion engines. Simulation results are discussed focusing attention on the mixing effects of the fuel components.