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 Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 906 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 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 Flammability and Autoignition of Hydrocarbon Fuels Under Static and Dynamic Conditions written by J. M. Kuchta and published by . This book was released on 1962 with total page 30 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 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 The Autoignition Chemistries of Primary Reference Fuels Olefin paraffin Binary Mixtures and Non linear Octane Blending written by William R. Leppard and published by . This book was released on 1992 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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.
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 Autoignition Study of Diesel Diesel Surrogates and Dieselsurrogate Components at Low Temperature Combustion Conditions written by Mengyuan Wang and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because of increasingly stringent engine emissions and fuel economy standards, there is an urgent need for developing future diesel engines with higher efficiency and lower emissions. Therefore, low temperature combustion is currently being pursued to develop new types of advanced diesel engines. Since low temperature combustion is more sensitive to chemical kinetics, the understanding of the autoignition characteristics of diesel fuels under low-to-intermediate temperatures becomes important. In order to achieve the goal of higher efficiency and lower emissions diesel engines, both experimental and computational investigations of diesel fuels at low-to-intermediate temperatures need to be conducted, as the experimental autoignition results help develop a comprehensive understanding of diesel ignition and provide a validation database for model development, and a comprehensive chemical kinetic model of diesel is also imperative for accurate prediction of ignition and emissions characteristics of diesel engines. Because diesel fuels contain hundreds, even thousands of species, and the composition of diesel is too complex to model, it is also necessary to develop surrogate fuels, which are simpler mixtures that include fuel components representative of hydrocarbon classes found in diesel fuels, and can capture the essential chemical/physical properties and performance characteristics of the target diesel fuel to sufficient accuracy. Therefore, the work presented in the current dissertation aims to gain better understandings and fill in gaps in fundamental combustion data of diesel-surrogate components and surrogate fuel mixtures relevant to diesel fuels. Autoignition of trans-decalin at low-to-intermediate temperatures has been investigated first to get a better understanding of its autoignition characteristics, and the development of a detailed chemical kinetic model of diesel surrogates has been benefited from the results of trans-decalin. The agreements of the developed diesel surrogate model have been tested by comparing with the current autoignition results of diesel surrogates, and possible sources of discrepancies between experimental and simulated results have also been investigated. Based on that, binary blends of iso-cetane and tetralin are further chosen for autoignition investigation to help find out possible reasons causing those discrepancies and to further benefit the refinement and development of comprehensive diesel surrogate models.
Download or read book Autoignition Characteristics of Diesel Fuel and Its Surrogates written by Goutham Kukkadapu and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The design process for development of engines could be made faster and less expensive with the help of computations which help understanding the processes prevalent in internal combustion engines. Running engine simulations are challenging as they need to accurately capture the fluid dynamic and chemical kinetic processes that occur in an engine. A major challenge in simulating chemical kinetic processes is the complexity of the fuel chemistry: real fuels are complex mixtures whose composition determines their physical properties and reactivity. The behavior of these real fuels can be conveniently represented using simpler mixtures often called â€surrogates mixtures†that match the key properties of the real fuels. Successful modeling of the ignition of real fuel first requires the formulation of an appropriate surrogate mixture whose compositions are carefully chosen in order to best emulate the combustion properties of the targeted real fuel. Then a comprehensive chemical kinetic model developed based on the surrogate fuel is used to simulate the combustion process of the real fuel. The work presented in the current dissertation intends to systematically study the surrogate modeling of diesel fuels. The study has been conducted to understand the ignition of surrogate fuel constituents and fully blended diesel fuels. Autoignition of tetralin, 1-methylnaphthalene, iso-cetane, and n-dodecane, the constituents of diesel surrogates, are investigated in the current dissertation. Besides, ignition of binary blends of the surrogate constituents has also been studied to investigate the effects of blending on ignition when neat components are blended to formulate a surrogate fuel. Furthermore, the ignition of two fully blended research grade diesel fuels has also been conducted inorder to provide quality ignition delay data for development and validation of chemical kinetic models of kinetic fuels.
Download or read book Ignition Behavior of Gasolines and Surrogate Fuels in Low Temperature Combustion Strategies written by Vickey Kalaskar and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation discusses the results from three different studies aimed at understanding the importance of fuel chemical structure during low temperature combustion (LTC) strategies, like homogeneous charge compression ignition (HCCI) and partially premixed combustion (PPC) employed in internal combustion (IC) engines wherein the focus is on high octane fuels. Boosted intake air operation combined with exhaust gas recirculation, internal as well as external, has become a standard path for expanding the load limits of IC engines employing LTC strategies mentioned above as well as conventional diesel and spark ignition (SI) engines. However, the effects of fuel compositional variation have not been fully explored. The first study focusses on three different fuels, where each of them were evaluated using a single cylinder boosted HCCI engine using negative valve overlap. The three fuels investigated were: a regular grade gasoline (RON = 90.2), 30% ethanol-gasoline blend (E30, RON = 100.3), and 24% iso-butanol-gasoline blend (IB24, RON = 96.6). Detailed sweeps of intake manifold pressure (atmospheric to 250 kPaa), EGR (0 -- 25% EGR), and injection timing were conducted to identify fuel-specific effects. While significant fuel compositional differences existed, the results showed that all these fuels achieved comparable operation with minor changes in operational conditions. Further, it was shown that the available enthalpy from the exhaust would not be sufficient to satisfy the boost requirements at higher load operation by doing an analysis of the required turbocharger efficiency. While the first study concentrated on load expansion of HCCI, it is important to mention that controlling LTC strategies is difficult under low load or idle operating conditions. To ensure stable operation, fuel injection in the negative valve overlap (NVO) is used as one of method of achieving combustion control. However the combustion chemistry under high temperature and fuel rich conditions that exist during the NVO have not been previously explored. The second study focused on examining the products of fuel rich chemistry as a result of fuel injection in the NVO. In this study, a unique six stroke cycle was used to segregate the exhaust from the NVO and to study the chemistry of the range of fuels injected during NVO under low oxygen conditions. The fuels investigated were methanol, ethanol, iso-butanol, and iso-octane. It was observed that the products of reactions under NVO conditions were highly dependent on the injected fuel's structure with iso-octane producing less than 1.5% hydrogen and methanol producing more than 8%. However a weak dependence was observed on NVO duration and initial temperature, indicating that NVO reforming was kinetically limited. Finally, the experimental trends were compared with CHEMKIN (single zone, 0-D model) predictions using multiple kinetic mechanism that were readily available through literature. Due to the simplicity of the model and inadequate information on the fuel injection process, the experimental data was not modeled well with the mechanisms tested. Some of the shortcomings of the 0-D model were probably due to the model ignoring temperature and composition spatial inhomogeneities and evaporative cooling from fuel vaporization.Though the results from the NVO injection and boosted NVO-HCCI studies are enlightening, the fundamentals of the autoignition behavior of gasoline, alcohols, and their mixtures are not entirely understood despite the interest in high octane fuels in compression engines from a point of view of better thermal efficiency. The third study focused on higher octane blends consisting of binary and ternary mixtures of n-heptane and/or iso-octane, and a fuel of interest. These fuels of interest were toluene, ethanol, and iso-butanol. In this study, the autoignition of such blends is studied under lean conditions ([phi] = 0.25) with varying intake pressure (atmospheric to 3 bar, abs) and at a constant intake temperature of 155 °C. The blends consisted of varying percentages of fuels of interest and their research octane number (RON) approximately estimated at 100 and 80. For comparison, neat iso-octane was selected as RON 100 fuel and PRF 80 blend was selected as RON 80 fuel. It was observed that the blends with a higher percentage of n-heptane showed a stronger tendency to autoignite at lower intake pressures. However, as the intake pressure was increased, the non-reactive components, in this case, the higher octane blend components (toluene, ethanol, and iso-butanol), reduced this tendency subsequently delaying the critical compression ratio (CCR) of the blends. The heat release analysis revealed that the higher octane components in the blends reduced the low temperature reactivity of n-heptane and iso-octane. GC-MS and GC-FID analysis of the partially compressed fuel also indicated that the higher octane components did affect the conversion of the more reactive components, n-heptane and iso-octane, into their partially oxidized branched hydrocarbons in the binary/ternary blends, and reduced the overall reactivity which resulted in a delayed CCR at higher intake pressures.
Download or read book Recommendations on the Transport of Dangerous Goods Model written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ADR Applicable as from 1 January 2011 written by and published by United Nations Publications. This book was released on 2010 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This authoritative Agreement is intended to increase the safety of international transport of dangerous goods by road. Regularly amended and updated since its entry into force, it contains the conditions under which dangerous goods may be carried internationally. This version has been prepared on the basis of amendments applicable as from 1 January 2011. It contains in particular revised provisions concerning the carriage of dangerous goods packed in limited quantities and the carriage of substances which are toxic by inhalation, new criteria for the classification of environmentally hazardous substances, revised requirements for the construction and testing of pressure receptacles, tanks, battery-vehicles and MEGCs, including conformity assessment and periodic inspection, as well as revised provisions for the training of drivers, the safety obligations of unloaders and instructions in writing to be carried on board the vehicle."--Publisher's description.
Download or read book Planning and Preparing for Emergency Response to Transport Accidents Involving Radioactive Material written by International Atomic Energy Agency and published by Safety Standards Series. This book was released on 2002 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides guidance on various aspects of emergency planning and preparedness for dealing effectively and safely with transport accidents involving radioactive material, including the assignment of responsibilities.
