The Experts below are selected from a list of 624 Experts worldwide ranked by ideXlab platform
Roland Dauphin - One of the best experts on this subject based on the ideXlab platform.
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Design of a valuable Fuel Couple and engine compression ratio for an Octane-On-Demand SI Engine Concept: a simulation approach using experimental data.
Fuel, 2017Co-Authors: Marie Bedon, Misa Milosavljevic, Jean-pascal Solari, Guillaume Bourhis, Virginie Morel, Roland DauphinAbstract:The efficiency of spark ignition engine is usually limited by the appearance of knock, which is linked to fuel Octane Number (Research Octane Number – RON and Motor Octane Number-MON). If running the engine at its optimal efficiency requests a high Octane Number at high load, a lower Octane Number is only needed at low load. Based on this, the application of so-called Octane On demand concept, whereby the fuel anti knock quality is customized to match the real time requirement of a conventional spark ignition engine has been identified as highly promising. The objective of this study is to define the best fuel couple for the dual fuel " Octane-On-Demand " concept, including a low RON based fuel and an Octane booster for minimizing global CO 2 tailpipe emissions and the Octane booster consumption. The work covers 4 Octane boosters: ethanol, reformate, di-isobutylene, and Superbutol™, and two fuel baseline: non-oxygenated gasoline RON 91 and naphtha based fuel RON 71. The present activity uses 0D vehicle simulations, based on a M-segment vehicle equipped with an up-to-date 1,6L turbocharged GDI engine, to guide the choice of the fuel couple together with the optimal engine compression ratio. Dedicated inputs, such as engine Octane requirement map and fuel anti-knock properties of various blends, are given to properly run the model.
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Knock management for dual fuel SI engines: RON evolution when mixing low RON base fuels with Octane boosters
Fuel, 2015Co-Authors: Nikola Rankovic, Mélanie Loos, Guillaume Bourhis, Roland DauphinAbstract:Most of the time, Spark Ignition (SI) engine performance is limited by knock phenomena (especially for turbocharged engines), which are linked to fuel resistance to auto-ignition, quantified by its Octane Number (Research Octane Number – RON and Motor Octane Number-MON). If high Octane Numbers are crucial for efficient high load operating points, they are less necessary at low load. Thus, if the Octane Number of the fuel could be tuned as any other engine setting parameter, the engine efficiency and CO 2 emissions could be improved, leading to an " Octane on Demand " concept, using for instance a dual fuel strategy. This requires understanding the behavior of dual fuel combustions with lower / higher Octane fuels, and more particularly the evolution of RON when blending high RON fuels with low RON ones. Developing an Octane on Demand concept requires to choose appropriate Octane enhancers and understand their blending behavior. For this purpose, RON measurements were performed on a CFR engine using a wide range of mixtures of low-Octane base fuels with various boosters capable of increasing the antiknock resistance of the blends. The chemical composition of booster streams was chosen to assess the potential of using alternative refinery products for improving fuel resistant auto-ignition properties when added to a whole-range naphtha and RON 91 gasoline. The study covers five Octane boosters: ethanol, reformate, di-isobutylene, 2-butanol, and a mixture of butanols.
Gautam Kalghatgi - One of the best experts on this subject based on the ideXlab platform.
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Exploring Alternative Octane Specification Methods for Improved Gasoline Knock Resistance in Spark-Ignition Engines
Frontiers in Mechanical Engineering, 2018Co-Authors: Amir F.n. Abdul-manan, Gautam Kalghatgi, Hassan BabikerAbstract:Different Octane specification methods were evaluated under rising ethanol blending volumes by adopting a refinery economics model to represent a region in the U.S.. It was demonstrated that the traditional Octane specification methods, such as the Anti-knock Index (AKI) used in the U.S., or the Research Octane Number (RON) and Motor Octane Number (MON) used in the EU, can lead to counterintuitive drop in Octane sensitivity with increased availability of ethanol. This is undesirable for modern gasoline engines that require fuels with high RON and low MON, but it is a consequence of how a refinery reformulates the gasoline blendstock, resulting in more naphtha being used in the final composition. The use of a new specification method based on Octane index (OI), with engine constant K = -1, internalizes the diminishing role that MON plays in modern engines, thus ensures that the desirable anti-knock quality is being met either through higher RON and/or higher sensitivity. Initial assessment suggests a potential engine efficiency benefit (~ 1.5%) to be gained simply by switching from an AKI-based specification method to an equivalent OI-based method.
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relating the Octane Numbers of fuels to ignition delay times measured in an ignition quality tester iqt
Fuel, 2017Co-Authors: Nimal Naser, Gautam Kalghatgi, Seung Yeon Yang, Suk Ho ChungAbstract:Abstract A methodology for estimating the Octane index (OI), the research Octane Number (RON) and the Motor Octane Number (MON) using ignition delay times from a constant volume combustion chamber with liquid fuel injection is proposed by adopting an ignition quality tester. A baseline data of ignition delay times were determined using an ignition quality tester at a charge pressure of 21.3 bar between 770 and 850 K and an equivalence ratio of 0.7 for various primary reference fuels (PRFs, mixtures of iso-Octane and n-heptane). Our methodology was developed using ignition delay times for toluene reference fuels (mixtures of toluene and n-heptane). A correlation between the OI and the ignition delay time at the initial charge temperature enabled the OI of non-PRFs to be predicted at specified temperatures. The methodology was validated using ignition delay times for toluene primary reference fuels (ternary mixtures of toluene, iso-Octane, and n-heptane), fuels for advanced combustion engines (FACE) gasolines, and certification gasolines. Using this methodology, the RON, the MON, and the Octane sensitivity were estimated in agreement with values obtained from standard test methods. A correlation between derived cetane Number and RON is also provided.
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a methodology to relate Octane Numbers of binary and ternary n heptane iso Octane and toluene mixtures with simulated ignition delay times
Fuel, 2015Co-Authors: Jihad Badra, Gautam Kalghatgi, Nehal Bokhumseen, Najood Mulla, Mani S Sarathy, Aamir Farooq, Patrick GaillardAbstract:Abstract Predicting Octane Numbers (ON) of gasoline surrogate mixtures is of significant importance to the optimization and development of internal combustion (IC) engines. Most ON predictive tools utilize blending rules wherein measured Octane Numbers are fitted using linear or non-linear mixture fractions on a volumetric or molar basis. In this work, the Octane Numbers of various binary and ternary n-heptane/iso-Octane/toluene blends, referred to as toluene primary reference fuel (TPRF) mixtures, are correlated with a fundamental chemical kinetic parameter, specifically, homogeneous gas-phase fuel/air ignition delay time. Ignition delay times for stoichiometric fuel/air mixtures are calculated at various constant volume conditions (835 K and 20 atm, 825 K and 25 atm, 850 K and 50 atm (research Octane Number RON-like) and 980 K and 45 atm (Motor Octane Number MON-like)), and for variable volume profiles calculated from cooperative fuel research (CFR) engine pressure and temperature simulations. Compression ratio (or ON) dependent variable volume profile ignition delay times are investigated as well. The constant volume RON-like ignition delay times correlation with RON was the best amongst the other studied conditions. The variable volume ignition delay times condition correlates better with MON than the ignition delay times at the other tested conditions. The best correlation is achieved when using compression ratio dependent variable volume profiles to calculate the ignition delay times. Most of the predicted research Octane Numbers (RON) have uncertainties that are lower than the repeatability and reproducibility limits of the measurements. Motor Octane Number (MON) correlation generally has larger uncertainties than that of RON.
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The outlook for fuels for internal combustion engines
International Journal of Engine Research, 2014Co-Authors: Gautam KalghatgiAbstract:The demand for transport energy is increasing, but this increase is heavily skewed toward heavier fuels such as diesel and jet fuel while the demand for gasoline might decrease. As spark-ignition engines develop to become more efficient, abnormal combustion such as knock and preignition will become more likely. High antiknock quality fuels, those with high research Octane Number and preferably low Motor Octane Number, will enable future spark-ignition engines to reach their full potential. Higher fuel antiknock quality is also likely to mitigate “superknock” resulting from preignition—an abnormal combustion problem in turbocharged spark-ignition engines. In many parts of the world, fuel antiknock specifications are set on the assumption that higher Motor Octane Number contributes to increased knock resistance. Specifications for fuel antiknock quality have a great impact on fuels manufacture and will need to be revised as this mismatch between existing specifications and engine requirements widens. The pr...
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WITHDRAWN: Developments in internal combustion engines and implications for combustion science and future transport fuels
Proceedings of the Combustion Institute, 2014Co-Authors: Gautam KalghatgiAbstract:Abstract Changes in engine technology, driven by the need to increase the efficiency of the SI engine and reduce NOx and soot from diesel engines, and in transport energy demand will have a profound effect on the properties, specifications and production of future fuels. The expected increase in global demand for transport energy is significantly skewed towards heavier fuels like jet fuel and diesel compared to gasoline. Abnormal combustion such as knock and preignition will become more likely as spark-ignition (SI) engines develop to become more efficient and fuel antiknock quality will become more important. In current and future SI engines, for a given RON (research Octane Number), a fuel of lower MON (Motor Octane Number) has better antiknock quality. Current fuel specifications in several parts of the world assume that MON contributes to antiknock quality and will need to be revised as the mismatch with engine requirements widens. Diesel engines need to maintain efficiency while reducing emissions of soot and NOx. Soot and NOx can be controlled more easily if such engines are run on fuels of extremely low cetane. In the long term compression ignition engines could run on fuels which require less processing in the refinery compared to today’s fuels. Such an engine/fuel system could be significantly cheaper and also help mitigate the expected demand imbalance in favour of heavier fuels. The review concludes with a list of issues for combustion science that are relevant to this fuel and engine development.
Jihad Badra - One of the best experts on this subject based on the ideXlab platform.
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Ignition delay measurements of a low-Octane gasoline blend, designed for gasoline compression ignition (GCI) engines
Proceedings of the Combustion Institute, 2019Co-Authors: Mohammed Alabbad, Jihad Badra, Khalil Djebbi, Aamir FarooqAbstract:Abstract A blend of low-Octane (light and heavy naphtha) and high-Octane (reformate) distillate fuels has been proposed for powering gasoline compression ignition (GCI) engines. The formulated ‘GCI blend’ has a research Octane Number (RON) of 77 and a Motor Octane Number (MON) of 73.9. In addition to ∼64 mole% paraffinic components, the blend contains ∼20 mole% aromatics and ∼15 mole% naphthenes. Experimental and modeling studies have been conducted in this work to assess autoignition characteristics of the GCI blend. Ignition delay times were measured in a shock tube and a rapid comparison machine over wide ranges of experimental conditions (20 and 40 bar, 640–1175 K, ϕ = 0.5, 1 and 2). Reactivity of the GCI blend was compared with experimental measurements of two surrogates: a multi-component surrogate (MCS) and a two-component primary reference fuel (PRF 77). Both surrogates capture the reactivity of the fuel quite well at high and intermediate temperatures. The MCS does a better job of emulating the fuel reactivity at low temperatures, where PRF 77 is more reactive than the GCI blend. Ignition delay times of the two surrogates are also simulated using detailed chemical kinetic models, and the simulations agree well with the experimental findings. The results of rate-of-production analyses show important role of cycloalkane chemistry in the overall autoignition behavior of the fuel at low temperatures.
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Autoignition of straight-run naphtha: A promising fuel for advanced compression ignition engines
Combustion and Flame, 2018Co-Authors: Mohammed Alabbad, Jihad Badra, Khalil Djebbi, S. Mani Sarathy, Gani Issayev, Alexander K. Voice, Binod Raj Giri, Ahfaz Ahmed, Aamir FarooqAbstract:Abstract Naphtha, a low-Octane distillate fuel, has been proposed as a promising low-cost fuel for advanced compression ignition engine technologies. Experimental and modelling studies have been conducted in this work to assess autoignition characteristics of naphtha for use in advanced engines. Ignition delay times of a certified straight-run naphtha fuel, supplied by Haltermann Solutions, were measured in a shock tube and a rapid comparison machine over wide ranges of experimental conditions (20 and 60 bar, 620–1223 K, ϕ = 0.5, 1 and 2). The Haltermann straight-run naphtha (HSRN) has research Octane Number (RON) of 60 and Motor Octane Number (MON) of 58.3, with carbon range spanning C3–C9. Reactivity of HSRN was compared, via experiments and simulations, with three suitably formulated surrogates: a two-component PRF (n-heptane/iso-Octane) surrogate, a three-component TPRF (toluene/n-heptane/iso-Octane) surrogate, and a six-component surrogate. All surrogates reasonably captured the ignition delays of HSRN at high and intermediate temperatures. However, at low temperatures (T
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Chemical Kinetic Insights into the Octane Number and Octane Sensitivity of Gasoline Surrogate Mixtures
Energy & Fuels, 2017Co-Authors: Eshan Singh, Jihad Badra, Marco Mehl, S. Mani SarathyAbstract:Gasoline Octane Number is a significant empirical parameter for the optimization and development of internal combustion engines capable of resisting knock. Although extensive databases and blending rules to estimate the Octane Numbers of mixtures have been developed and the effects of molecular structure on autoignition properties are somewhat understood, a comprehensive theoretical chemistry-based foundation for blending effects of fuels on engine operations is still to be developed. In this study, we present models that correlate the research Octane Number (RON) and Motor Octane Number (MON) with simulated homogeneous gas-phase ignition delay times of stoichiometric fuel/air mixtures. These correlations attempt to bridge the gap between the fundamental autoignition behavior of the fuel (e.g., its chemistry and how reactivity changes with temperature and pressure) and engine properties such as its knocking behavior in a cooperative fuels research (CFR) engine. The study encompasses a total of 79 hydrocar...
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Ignition studies of n-heptane/iso-Octane/toluene blends
Combustion and Flame, 2016Co-Authors: Tamour Javed, Jihad Badra, Changyoul Lee, Mohammed Alabbad, Khalil Djebbi, Mohamed Beshir, Henry J. Curran, Aamir FarooqAbstract:Ignition delay times of four ternary blends of n-heptane/iso-Octane/toluene, referred to as Toluene Primary Reference Fuels (TPRFs), have been measured in a high-pressure shock tube and in a rapid compression machine. The TPRFs were formulated to match the research Octane Number (RON) and Motor Octane Number (MON) of two high-Octane gasolines and two prospective low-Octane naphtha fuels. The experiments were carried out over a wide range of temperatures (650–1250 K), at pressures of 10, 20 and 40 bar, and at equivalence ratios of 0.5 and 1.0. It was observed that the ignition delay times of these TPRFs exhibit negligible Octane dependence at high temperatures (T > 1000 K), weak Octane dependence at low temperatures (T
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a methodology to relate Octane Numbers of binary and ternary n heptane iso Octane and toluene mixtures with simulated ignition delay times
Fuel, 2015Co-Authors: Jihad Badra, Gautam Kalghatgi, Nehal Bokhumseen, Najood Mulla, Mani S Sarathy, Aamir Farooq, Patrick GaillardAbstract:Abstract Predicting Octane Numbers (ON) of gasoline surrogate mixtures is of significant importance to the optimization and development of internal combustion (IC) engines. Most ON predictive tools utilize blending rules wherein measured Octane Numbers are fitted using linear or non-linear mixture fractions on a volumetric or molar basis. In this work, the Octane Numbers of various binary and ternary n-heptane/iso-Octane/toluene blends, referred to as toluene primary reference fuel (TPRF) mixtures, are correlated with a fundamental chemical kinetic parameter, specifically, homogeneous gas-phase fuel/air ignition delay time. Ignition delay times for stoichiometric fuel/air mixtures are calculated at various constant volume conditions (835 K and 20 atm, 825 K and 25 atm, 850 K and 50 atm (research Octane Number RON-like) and 980 K and 45 atm (Motor Octane Number MON-like)), and for variable volume profiles calculated from cooperative fuel research (CFR) engine pressure and temperature simulations. Compression ratio (or ON) dependent variable volume profile ignition delay times are investigated as well. The constant volume RON-like ignition delay times correlation with RON was the best amongst the other studied conditions. The variable volume ignition delay times condition correlates better with MON than the ignition delay times at the other tested conditions. The best correlation is achieved when using compression ratio dependent variable volume profiles to calculate the ignition delay times. Most of the predicted research Octane Numbers (RON) have uncertainties that are lower than the repeatability and reproducibility limits of the measurements. Motor Octane Number (MON) correlation generally has larger uncertainties than that of RON.
Guillaume Bourhis - One of the best experts on this subject based on the ideXlab platform.
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Design of a valuable Fuel Couple and engine compression ratio for an Octane-On-Demand SI Engine Concept: a simulation approach using experimental data.
Fuel, 2017Co-Authors: Marie Bedon, Misa Milosavljevic, Jean-pascal Solari, Guillaume Bourhis, Virginie Morel, Roland DauphinAbstract:The efficiency of spark ignition engine is usually limited by the appearance of knock, which is linked to fuel Octane Number (Research Octane Number – RON and Motor Octane Number-MON). If running the engine at its optimal efficiency requests a high Octane Number at high load, a lower Octane Number is only needed at low load. Based on this, the application of so-called Octane On demand concept, whereby the fuel anti knock quality is customized to match the real time requirement of a conventional spark ignition engine has been identified as highly promising. The objective of this study is to define the best fuel couple for the dual fuel " Octane-On-Demand " concept, including a low RON based fuel and an Octane booster for minimizing global CO 2 tailpipe emissions and the Octane booster consumption. The work covers 4 Octane boosters: ethanol, reformate, di-isobutylene, and Superbutol™, and two fuel baseline: non-oxygenated gasoline RON 91 and naphtha based fuel RON 71. The present activity uses 0D vehicle simulations, based on a M-segment vehicle equipped with an up-to-date 1,6L turbocharged GDI engine, to guide the choice of the fuel couple together with the optimal engine compression ratio. Dedicated inputs, such as engine Octane requirement map and fuel anti-knock properties of various blends, are given to properly run the model.
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Knock management for dual fuel SI engines: RON evolution when mixing low RON base fuels with Octane boosters
Fuel, 2015Co-Authors: Nikola Rankovic, Mélanie Loos, Guillaume Bourhis, Roland DauphinAbstract:Most of the time, Spark Ignition (SI) engine performance is limited by knock phenomena (especially for turbocharged engines), which are linked to fuel resistance to auto-ignition, quantified by its Octane Number (Research Octane Number – RON and Motor Octane Number-MON). If high Octane Numbers are crucial for efficient high load operating points, they are less necessary at low load. Thus, if the Octane Number of the fuel could be tuned as any other engine setting parameter, the engine efficiency and CO 2 emissions could be improved, leading to an " Octane on Demand " concept, using for instance a dual fuel strategy. This requires understanding the behavior of dual fuel combustions with lower / higher Octane fuels, and more particularly the evolution of RON when blending high RON fuels with low RON ones. Developing an Octane on Demand concept requires to choose appropriate Octane enhancers and understand their blending behavior. For this purpose, RON measurements were performed on a CFR engine using a wide range of mixtures of low-Octane base fuels with various boosters capable of increasing the antiknock resistance of the blends. The chemical composition of booster streams was chosen to assess the potential of using alternative refinery products for improving fuel resistant auto-ignition properties when added to a whole-range naphtha and RON 91 gasoline. The study covers five Octane boosters: ethanol, reformate, di-isobutylene, 2-butanol, and a mixture of butanols.
Patrick Gaillard - One of the best experts on this subject based on the ideXlab platform.
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a methodology to relate Octane Numbers of binary and ternary n heptane iso Octane and toluene mixtures with simulated ignition delay times
Fuel, 2015Co-Authors: Jihad Badra, Gautam Kalghatgi, Nehal Bokhumseen, Najood Mulla, Mani S Sarathy, Aamir Farooq, Patrick GaillardAbstract:Abstract Predicting Octane Numbers (ON) of gasoline surrogate mixtures is of significant importance to the optimization and development of internal combustion (IC) engines. Most ON predictive tools utilize blending rules wherein measured Octane Numbers are fitted using linear or non-linear mixture fractions on a volumetric or molar basis. In this work, the Octane Numbers of various binary and ternary n-heptane/iso-Octane/toluene blends, referred to as toluene primary reference fuel (TPRF) mixtures, are correlated with a fundamental chemical kinetic parameter, specifically, homogeneous gas-phase fuel/air ignition delay time. Ignition delay times for stoichiometric fuel/air mixtures are calculated at various constant volume conditions (835 K and 20 atm, 825 K and 25 atm, 850 K and 50 atm (research Octane Number RON-like) and 980 K and 45 atm (Motor Octane Number MON-like)), and for variable volume profiles calculated from cooperative fuel research (CFR) engine pressure and temperature simulations. Compression ratio (or ON) dependent variable volume profile ignition delay times are investigated as well. The constant volume RON-like ignition delay times correlation with RON was the best amongst the other studied conditions. The variable volume ignition delay times condition correlates better with MON than the ignition delay times at the other tested conditions. The best correlation is achieved when using compression ratio dependent variable volume profiles to calculate the ignition delay times. Most of the predicted research Octane Numbers (RON) have uncertainties that are lower than the repeatability and reproducibility limits of the measurements. Motor Octane Number (MON) correlation generally has larger uncertainties than that of RON.