Download or read book Autoignition Chemistry Studies on Primary Reference Fuels in a Motored Engine written by Houliang Li and published by . This book was released on 1994 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Autoignition Chemistry Studies of Primary Reference Fuels and Their Mixtures with Oxygenates in a Research Engine written by Houliang Li and published by . This book was released on 1996 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Autoignition Chemistry in a Motored Engine written by and published by . This book was released on 1996 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autoignition of isomers of pentane, hexane, and primary reference fuel mixture of n-heptane and iso-octane has been studied experimentally under motored engine conditions and computationally using a detailed chemical kinetic reaction mechanism. Computed and experimental results are compared and used to help understand the chemical factors leading to engine knock in spark-ignited engines. The kinetic model reproduces observed variations in critical compression ratio with fuel molecular size and structure, provides intermediate product species concentrations in good agreement with observations, and gives insights into the kinetic origins of fuel octane sensitivity. Sequential computed engine cycles were found to lead to stable, non-igniting behavior for conditions below a critical compression ratio; to unstable, oscillating but nonigniting behavior in a transition region; and eventually to ignition as the compression ratio is steadily increased. This transition is related to conditions where a negative temperature coefficient of reaction exists, which has a significant influence on octane number and fuel octane sensitivity.
Download or read book A Study of Autoignition in a Premixed Charge Internal Combustion Engine Using Comprehensive Chemical Kinetics written by Philip Michael Dimpelfeld and published by . This book was released on 1985 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oxidation of Automotive Primary Reference Fuels at Elevated Pressures written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Automotive engine knock limits the maximum operating compression ratio and ultimate thermodynamic efficiency of spark-ignition (SI) engines. In compression-ignition (CI) or diesel cycle engines, the premixed burn phase, which occurs shortly after injection, determines the time it takes for autoignition to occur. In order to improve engine efficiency and to recommend more efficient, cleaner-burning alternative fuels, they must understand the chemical kinetic processes that lead to autoignition in both SI and CI engines. These engines burn large molecular-weight blended fuels, a class to which the primary reference fuels (PRF) n-heptane and iso-octane belong. In this study, experiments were performed under engine like conditions in a high-pressure flow reactor using both the pure PRF fuels and their mixtures in the temperature range 550-880 K and 12.5 atm pressure. These experiments not only provide information on the reactivity of each fuel but also identify the major intermediate products formed during the oxidation process. A detailed chemical kinetic mechanism is used to simulate these experiments, and comparisons of experimentally measured and model predicted profiles for O2, CO, CO2, H2O and temperature rise are presented. Intermediates identified in the flow reactor are compared with those present in the computations, and the kinetic pathways leading to their formation are discussed. In addition, autoignition delay times measured in a shock tube over the temperature range 690-1220 K and at 40 atm pressure were simulated. Good agreement between experiment and simulation was obtained for both the pure fuels and their mixtures. Finally, quantitative values of major intermediates measured in the exhaust gas of a cooperative fuels research engine operating under motored engine conditions are presented together with those predicted by the detailed model.
Download or read book Oxidation of Automotive Primary Reference Fuels in a High Pressure Flow Reactor written by and published by . This book was released on 1998 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Automotive engine knock limits the maximum operating compression ratio and ultimate thermodynamic efficiency of spark-ignition (SI) engines. In compression-ignition (CI) or diesel cycle engines the premixed urn phase, which occurs shortly after injection, determines the time it takes for autoignition to occur. In order to improve engine efficiency and to recommend more efficient, cleaner-burning alternative fuels, we must understand the chemical kinetic processes which lead to autoignition in both SI and CI engines. These engines burn large molecular-weight blended fuels, a class to which the primary reference fuels (PRF), n-heptane and isooctane belong. In this study, experiments were performed under engine-like conditions in a high pressure flow reactor using both the pure PRF fuels and their mixtures in the temperature range 550-880 K and at 12.5 atm pressure. These experiments not only provide information on the reactivity of each fuel but also identify the major intermediate products formed during the oxidation process. A detailed chemical kinetic mechanism is used to simulate these experiments and comparisons of experimentally measures and model predicted profiles for O2, CO, CO2, H2O and temperature rise are presented. Intermediates identified in the flow reactor are compared with those present in the computations, and the kinetic pathways leading to their formation are discussed. In addition, autoignition delay times measured in a shock tube over the temperature range 690- 1220 K and at 40 atm pressure were simulated. Good agreement between experiment and simulation was obtained for both the pure fuels and their mixtures. Finally, quantitative values of major intermediates measured in the exhaust gas of a cooperative fuels research engine operating under motored engine conditions are presented together with those predicted by the detailed method.
Download or read book Autoignition and Emissions related Chemistry of Primary Reference Fuels and Gasoline Components written by Charles V. Callahan and published by . This book was released on 1995 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Fundamental Study of the Autoignition Behavior of SI Primary Reference Fuels with Propionaldehyde and DTBP as an Additive written by Rodney O. Johnson and published by . This book was released on 2007 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combustion Engines Development written by Günter P. Merker and published by Springer Science & Business Media. This book was released on 2011-09-24 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion Engines Development nowadays is based on simulation, not only of the transient reaction of vehicles or of the complete driveshaft, but also of the highly unsteady processes in the carburation process and the combustion chamber of an engine. Different physical and chemical approaches are described to show the potentials and limits of the models used for simulation.
Download or read book Reactivity Studies of Primary Reference Fuel Blends in a Motored Engine written by David Joseph Filipe and published by . This book was released on 1992 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Autoignition Characteristics of Primary Reference Fuels and Their Mixtures written by A. Tyler Little and published by . This book was released on 2008 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Internal combustion (IC) engine knock is characterized by uncontrolled autoignition of a mixture of fuel and oxidizer, whereas homogeneous charge compression ignition (HCCI) relies on controlling the autoignition to achieve a favorable engine performance. This study investigates the autoignition of Primary Reference Fuels (PRFs) using the kinetic model by Curran et al. (2002). The CHEMKIN (2006) software is used to facilitate solutions in a constant volume reactor and a variable volume reactor representing an internal combustion engine. Both models assume homogeneous mixing of fuel and oxidizer. Experimental data for shock tube ignition delay times and HCCI engine pressures and temperatures have been obtained from literature. First, shock tube data is compared with the present predictions in the constant volume adiabatic reactor for a range of inlet temperatures and fuel octane numbers. CHEMKIN's IC engine model with a heat transfer correlation is then used to reproduce the engine experimental data. Finally, a parametric study of the effect of inlet pressure, inlet temperature, octane number, fuel/air equivalence ratio, and exhaust gas recirculation (EGR) on the autoignition of PRF/air mixtures is conducted.
Download or read book Low temperature Combustion and Autoignition written by M.J. Pilling and published by Elsevier. This book was released on 1997-11-27 with total page 823 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Simulating Combustion written by Günter P. Merker and published by Springer Science & Business Media. This book was released on 2005-12-17 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: The numerical simulation of combustion processes in internal combustion engines, including also the formation of pollutants, has become increasingly important in the recent years, and today the simulation of those processes has already become an indispensable tool when - veloping new combustion concepts. While pure thermodynamic models are well-established tools that are in use for the simulation of the transient behavior of complex systems for a long time, the phenomenological models have become more important in the recent years and have also been implemented in these simulation programs. In contrast to this, the thr- dimensional simulation of in-cylinder combustion, i. e. the detailed, integrated and continuous simulation of the process chain injection, mixture formation, ignition, heat release due to combustion and formation of pollutants, has been significantly improved, but there is still a number of challenging problems to solve, regarding for example the exact description of s- processes like the structure of turbulence during combustion as well as the appropriate choice of the numerical grid. While chapter 2 includes a short introduction of functionality and operating modes of internal combustion engines, the basics of kinetic reactions are presented in chapter 3. In chapter 4 the physical and chemical processes taking place in the combustion chamber are described. Ch- ter 5 is about phenomenological multi-zone models, and in chapter 6 the formation of poll- ants is described.
Download or read book The Autoignition Chemistry of Isobutane written by William R. Leppard and published by . This book was released on 1988 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of Iso octane Auto ignition Using a Rapid Compression Facility written by Xin He and published by . This book was released on 2005 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Internal Combustion Engine Research written by Dhananjay Kumar Srivastava and published by Springer. This book was released on 2017-11-29 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses all aspects of advanced engine technologies, and describes the role of alternative fuels and solution-based modeling studies in meeting the increasingly higher standards of the automotive industry. By promoting research into more efficient and environment-friendly combustion technologies, it helps enable researchers to develop higher-power engines with lower fuel consumption, emissions, and noise levels. Over the course of 12 chapters, it covers research in areas such as homogeneous charge compression ignition (HCCI) combustion and control strategies, the use of alternative fuels and additives in combination with new combustion technology and novel approaches to recover the pumping loss in the spark ignition engine. The book will serve as a valuable resource for academic researchers and professional automotive engineers alike.
Download or read book Autoignition Study of Ethanol and Heptane in a Rapid Compression Machine written by Varun Anthony Davies and published by . This book was released on 2015 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Practical fuels are a complex mixture of thousands of hydrocarbon compounds, making it challenging and difficult to study their combustion behavior. It's generally agreed that in order to study these complex practical fuels a much simpler approach of studying simple fuel surrogates containing limited number of components is more feasible. Ethanol and n-heptane have been studied as primary reference fuels in the surrogate study of gasoline and diesel over the past few decades. The objective of the following thesis has been to study the autoignition characteristics of ethanol and n-heptane and validate chemical kinetic mechanisms. The validation of a chemical kinetic mechanism provides a deeper insight into the combustion behavior of the fuels which can be further used to study advanced combustion concepts. Experiments have been conducted on the rapid compression machine (RCM) and validated against mechanisms from literature study. Rapid compression machines have been primarily used to study chemical kinetics at low to intermediate temperatures and high pressures for their accuracy and reproducibility. For the following study experiments span over a range of temperature (650-1000 K), pressure (10, 15 and 20 bar) and equivalence ratio ([phi]=0.3, 0.5, 1). Experimental data based on the adiabatic volumetric expansion approach have been modeled numerically using the Sandia SENKIN code in conjunction with CHEMKIN. Experiments have been primarily focused on validating kinetic mechanisms at low to intermediate temperatures and elevated pressures. Ignition delay time data from experiments have been deduced based on the pressure and time histories. A brute sensitivity and flux analysis has been performed to reveal the key sensitive reactions and the dominant reaction pathways followed under the present experimental conditions. Improvements have been suggested and discrepancies noted in order to develop a valid chemical kinetic mechanism. Under the present experimental conditions for the study of ethanol, reactions involving hydroperoxyl radicals, namely C2H5OH+HȮ2 and CH3CHO+ HȮ2 as well as the formation of H2O2 from HȮ2 radical and its subsequent decomposition have been found to be sensitive. Based on the following, improvements and developements have been suggested to increase the accuracy and predictability of the mechanisms studied. Ignition delay data from experiments have been compared against those obtained from the mechanism used in the study for n-heptane. Discrepancies have been found in the low temperature region, with the mechanism under predicting the first ignition delay. The causes for the discrepancy have been noted to be due to the NTC behaviour exhibited during the two stage ignition of n-heptane. At low temperatures the reaction pathway proceeded by chain branching mainly due to the ketohydroperoxide species reaction pathway has been analysed. As the temperature of the reaction increases the reaction pathway is dominated by the ȮOH species propagation resulting in the formation of conjugate olefins and [Beta]-decomposition products, a further investigation of which can help improve the predictability of the mechanism.
