The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform

William J Pitz - One of the best experts on this subject based on the ideXlab platform.

  • Autoignition response of n-butanol and its blends with primary Reference Fuel constituents of gasoline
    Combustion and Flame, 2015
    Co-Authors: Kamal Kumar, Chih-jen Sung, Yu Zhang, William J Pitz
    Abstract:

    Abstract We study the influence of blending n-butanol on the ignition delay times of n-heptane and iso-octane, the primary Reference Fuels for gasoline. The ignition delay times are measured using a rapid compression machine, with an emphasis on the low-to-intermediate temperature conditions. The experiments are conducted at equivalence ratios of 0.4 and 1.0, for a compressed pressure of 20 bar, with the temperatures at the end of compression ranging from 613 K to 979 K. The effect of n-butanol addition on the development of the two-stage ignition characteristics for the two primary Reference Fuels is also examined. The experimental results are compared to predictions obtained using a detailed chemical kinetic mechanism, which has been obtained by a systematic merger of previously reported base models for the combustion of the individual Fuel constituents. A sensitivity analysis on the base, and the merged models, is also performed to understand the dependence of autoignition delay times on the model parameters.

  • a kinetic modeling study on the oxidation of primary Reference Fuel toluene mixtures including cross reactions between aromatics and aliphatics
    Proceedings of the Combustion Institute, 2009
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    Abstract A detailed chemical kinetic model for the mixtures of primary Reference Fuel (PRF: n -heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura, Y. Sakai, A. Miyoshi, M. Koshi, P. Dagaut, Energy Fuels 21 (2007) 3233–3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [W.J. Pitz, R. Seiser, J.W. Bozzelli, et al., in: Chemical Kinetic Characterization of the Combustion of Toluene, Proceedings of the Second Joint Meeting of the U.S. Sections of the Combustion Institute , 2001] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai, H. Ozawa, T. Ogura, A. Miyoshi, M. Koshi, W.J. Pitz, Effects of Toluene Addition to Primary Reference Fuel at High Temperature , SAE 2007-01-4104, 2007]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of PRF/toluene mixtures under the wide range of temperatures (500–1700 K) and pressures (2–50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • A kinetic modeling study on the oxidation of primary Reference Fuel–toluene mixtures including cross reactions between aromatics and aliphatics
    Proceedings of the Combustion Institute, 2009
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    Abstract A detailed chemical kinetic model for the mixtures of primary Reference Fuel (PRF: n -heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura, Y. Sakai, A. Miyoshi, M. Koshi, P. Dagaut, Energy Fuels 21 (2007) 3233–3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [W.J. Pitz, R. Seiser, J.W. Bozzelli, et al., in: Chemical Kinetic Characterization of the Combustion of Toluene, Proceedings of the Second Joint Meeting of the U.S. Sections of the Combustion Institute , 2001] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai, H. Ozawa, T. Ogura, A. Miyoshi, M. Koshi, W.J. Pitz, Effects of Toluene Addition to Primary Reference Fuel at High Temperature , SAE 2007-01-4104, 2007]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of PRF/toluene mixtures under the wide range of temperatures (500–1700 K) and pressures (2–50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • Detailed chemical kinetic models for large n-alkanes and iso-alkanes found in conventional and F-T diesel Fuels
    2008
    Co-Authors: Charles K. Westbrook, William J Pitz, Henry J. Curran, Marco Mehl
    Abstract:

    Detailed chemical kinetic models are needed to simulate the combustion of current and future transportation Fuels. These models should represent the various chemical classes in these Fuels. Conventional diesel Fuels are composed of n-alkanes, iso-alkanes, cycloalkanes and aromatics (Farrell et al. 2007). For future Fuels, there is a renewed interest in Fischer-Tropsch (F-T) processes which can be used to synthesize diesel and other transportation Fuels from biomass, coal and natural gas. F-T diesel Fuels are expected to be similar to F-T jet Fuels which are commonly comprised of iso-alkanes with some n-alkanes (Smith and Bruno, 2008). Thus, n-alkanes and iso-alkanes are common chemical classes in these conventional and future Fuels. This paper reports on the development of chemical kinetic models of large n-alkanes and iso-alkanes to represent these chemical classes in conventional and future Fuels. Two large iso-alkanes are 2,2,4,4,6,8,8-heptamethylnonane, which is a primary Reference Fuel for diesel, and isooctane, a primary Reference Fuel for gasoline. Other iso-alkanes are branched alkanes with a single methyl side chain, typical of most F-T Fuels. The chemical kinetic models are then used to predict the effect of these Fuel components on ignition characteristics under conditions found in internal combustion engines.

  • a kinetic modeling study on the oxidation of primary Reference Fuel toluene mixtures including cross reactions between aromatics and aliphatics
    Presented at: 32nd International Symposium on Combustion Montreal Canada Aug 03 - Aug 08 2008, 2008
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    A detailed chemical kinetic model for the mixtures of Primary Reference Fuel (PRF: n-heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura et al., Energy & Fuels 21 (2007) 3233-3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [Proc. the 2nd Joint Meeting of the U.S. Combust. Institute (2001)] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross-reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai et al, SAE 2007-01-4014 (2007)]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of toluene and PRF/Toluene mixtures under the wide range of temperatures (500-1700 K) and pressures (2-50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

Usame Demir - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of an HCCI engine combustion using toluene Reference Fuel for different equivalence ratios – Comparison of experimental results with CFD and SRM simulations
    Fuel, 2019
    Co-Authors: Gökhan Coskun, Yusuf Delil, Usame Demir
    Abstract:

    Abstract In this study; performance of 0-D and Computational Fluid Dynamics (CFD) software with two different chemical mechanisms are investigated in an HCCI engine using toluene Reference Fuel (79% toluene and 21% n-heptane). For 0-D simulations, stochastic reactor model (SRM) has been used. SRM and CFD software were compared to each other for HCCI engine simulation by investigating in-cylinder pressure variations, Heat Release Rate (HRR) and emissions. For toluene Reference Fuel, a semi-detailed and a reduced chemical kinetic mechanisms were used during the simulations. It is observed that CFD and SRM simulations with reduced mechanism give better results for capturing pressure and HRR for lower lambda (λ) values. But only CFD simulation with reduced mechanism could capture the experimental pressure and HRR results for higher lambda (λ) values. On the other hand semi-detailed mechanism could predict early cold combustion reactions for all simulation strategies. It could be say that all simulation approaches with two different mechanism have almost similar results for HCCI combustion emissions.

  • Experimental and Stochastic Reactor Modeling Results of an HCCI Engine Fueled with Primary Reference Fuel
    Energy & Fuels, 2018
    Co-Authors: H. Yasar, E. Usta, Usame Demir
    Abstract:

    In recent years, much research has been performed in order to decrease Fuel consumption, noise, and exhaust emission levels in internal combustion engines. In this study, the effects of excess air coefficient on performance and exhaust emissions (CO, CO2) of an HCCI engine Fueled with primary Reference Fuel (PRF) were investigated for different intake air pressure and temperature values. The simulation studies were performed by using SRM Suite software. The chemical kinetic mechanism, which contains 138 species and 633 reactions that are embedded into the program, was used to simulate the combustion of the PRF Fuel during the combustion simulations. The analysis covers the full cycle and provides data about induction, compression, combustion, expansion, and exhaust. The exhaust emissions, cylinder pressure, and heat release rate results were compared with the experimental data. The zero-dimensional software (SRM Suite) gives quite reasonable results compared with the experimental data, and it has advantag...

  • Computational investigation of combustion and emission characteristics of toluene Reference Fuel (TRF) mixtures in an HCCI engine using stochastic reactor model
    Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2017
    Co-Authors: Gökhan Coskun, Usame Demir, N. Yilmaz, Hakan Serhad Soyhan
    Abstract:

    In this study, a homogeneous charge compression ignition (HCCI) engine was Fueled with primary Reference Fuel (PRF) and toluene mixture using a zero-dimensional simulation code called stochastic reactor model (SRM) for simulations. A mixture of the PRF with Toluene Fuel known as toluene Reference Fuel (TRF) was simulated using a skeletal kinetic mechanism consisting of 137 species and 633 reactions. Experimental results were used to validate SRM simulations’ accuracy. Acceptable agreement was found between the computational results and the experimental data. Furthermore, parametric studies of experimentally validated simulation were performed to understand the effects of TRF blends, various initial conditions and Fuel/air equivalence ratios ( Φ ) on combustion and emission characteristics of the HCCI engine, to help with engine control strategies.

  • evaluation of zero dimensional codes in simulating ic engines using primary Reference Fuel
    Applied Thermal Engineering, 2015
    Co-Authors: Usame Demir, Gökhan Coskun, Nadir Yilmaz, Hakan Serhad Soyhan
    Abstract:

    Abstract In this work, experimental results from a homogenous charge compression ignition (HCCI) engine Fueled with PRF-85 (85% iso-octane and 15% n-heptane) were used to compare performances of combustion codes for zero dimensional analysis. 0-D codes, called SRM Suite (Stochastic Reactor Model) and Chemkin-Pro, were evaluated in terms of combustion, heat transfer and emissions in an HCCI engine. The simulations are based on experimental data and operating conditions at Shell Research Labs in the UK. One set of experimental data was used for analysis in both programs with reduced and detailed kinetic mechanisms. Simulation results were compared to experimental data in terms of pressure, heat release rate, and emission. Variation of the temperature, OH and H2O2 that could not be obtained experimentally were evaluated for comparisons between the two codes. Analysis showed that both codes have advantages over each other. Crevice and blow-by, ring gap and probability density function (PDF) – based stochastic reactor modeling are main advantages of SRM Suite software and these capabilities helped with better convergence of the results. But, Chemkin-Pro results were acceptable and solution time was fairly shorter than SRM Suite. It was also seen that detailed and reduced kinetic mechanisms affected the analysis.

Yasuyuki Sakai - One of the best experts on this subject based on the ideXlab platform.

  • A kinetic modeling study on the oxidation of primary Reference Fuel–toluene mixtures including cross reactions between aromatics and aliphatics
    Proceedings of the Combustion Institute, 2009
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    Abstract A detailed chemical kinetic model for the mixtures of primary Reference Fuel (PRF: n -heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura, Y. Sakai, A. Miyoshi, M. Koshi, P. Dagaut, Energy Fuels 21 (2007) 3233–3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [W.J. Pitz, R. Seiser, J.W. Bozzelli, et al., in: Chemical Kinetic Characterization of the Combustion of Toluene, Proceedings of the Second Joint Meeting of the U.S. Sections of the Combustion Institute , 2001] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai, H. Ozawa, T. Ogura, A. Miyoshi, M. Koshi, W.J. Pitz, Effects of Toluene Addition to Primary Reference Fuel at High Temperature , SAE 2007-01-4104, 2007]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of PRF/toluene mixtures under the wide range of temperatures (500–1700 K) and pressures (2–50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • a kinetic modeling study on the oxidation of primary Reference Fuel toluene mixtures including cross reactions between aromatics and aliphatics
    Proceedings of the Combustion Institute, 2009
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    Abstract A detailed chemical kinetic model for the mixtures of primary Reference Fuel (PRF: n -heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura, Y. Sakai, A. Miyoshi, M. Koshi, P. Dagaut, Energy Fuels 21 (2007) 3233–3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [W.J. Pitz, R. Seiser, J.W. Bozzelli, et al., in: Chemical Kinetic Characterization of the Combustion of Toluene, Proceedings of the Second Joint Meeting of the U.S. Sections of the Combustion Institute , 2001] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai, H. Ozawa, T. Ogura, A. Miyoshi, M. Koshi, W.J. Pitz, Effects of Toluene Addition to Primary Reference Fuel at High Temperature , SAE 2007-01-4104, 2007]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of PRF/toluene mixtures under the wide range of temperatures (500–1700 K) and pressures (2–50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • a kinetic modeling study on the oxidation of primary Reference Fuel toluene mixtures including cross reactions between aromatics and aliphatics
    Presented at: 32nd International Symposium on Combustion Montreal Canada Aug 03 - Aug 08 2008, 2008
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    A detailed chemical kinetic model for the mixtures of Primary Reference Fuel (PRF: n-heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura et al., Energy & Fuels 21 (2007) 3233-3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [Proc. the 2nd Joint Meeting of the U.S. Combust. Institute (2001)] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross-reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai et al, SAE 2007-01-4014 (2007)]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of toluene and PRF/Toluene mixtures under the wide range of temperatures (500-1700 K) and pressures (2-50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • A Kinetic Modeling study on the Oxidation of Primary Reference Fuel?Toluene Mixtures Including Cross Reactions between Aromatics and Aliphatics
    2008
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    A detailed chemical kinetic model for the mixtures of Primary Reference Fuel (PRF: n-heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura et al., Energy & Fuels 21 (2007) 3233-3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [Proc. the 2nd Joint Meeting of the U.S. Combust. Institute (2001)] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross-reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai et al, SAE 2007-01-4014 (2007)]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of toluene and PRF/Toluene mixtures under the wide range of temperatures (500-1700 K) and pressures (2-50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • Modeling of the Oxidation of Primary Reference Fuel in the Presence of Oxygenated Octane Improvers: Ethyl Tert-Butyl Ether and Ethanol
    Energy and Fuels, 2007
    Co-Authors: Teppei Ogura, Akira Miyoshi, Mitsuo Koshi, Yasuyuki Sakai, Philippe Dagaut
    Abstract:

    A detailed chemical kinetic mechanism has been developed for the oxidation of primary Reference Fuel (PRF, mixture of n-heptane and iso-octane) in the presence of ethyl tert-butyl ether (ETBE) or ethanol. The mechanism was validated by comparison with the existing experimental data from shock tubes, a jet-stirred reactor, and a flow reactor. ETBE and ethanol are known as octane number improvers. Enhancement of research octane number (RON) by the addition of ETBE and ethanol to PRF has been measured using a cooperative Fuel research (CFR) engine. Increase in RON was simulated with the present detailed kinetic mechanism by estimating the critical compression ratio (CCR) for autoignition in a motored engine. The correlation curve between CCR and RON was derived by calculating the CCR for PRF whose composition defines the RON. The kinetic model reproduces observed variations in RON by the addition of ETBE and ethanol to PRF. Those additives showed a very similar effect on RON.

Mitsuo Koshi - One of the best experts on this subject based on the ideXlab platform.

  • A kinetic modeling study on the oxidation of primary Reference Fuel–toluene mixtures including cross reactions between aromatics and aliphatics
    Proceedings of the Combustion Institute, 2009
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    Abstract A detailed chemical kinetic model for the mixtures of primary Reference Fuel (PRF: n -heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura, Y. Sakai, A. Miyoshi, M. Koshi, P. Dagaut, Energy Fuels 21 (2007) 3233–3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [W.J. Pitz, R. Seiser, J.W. Bozzelli, et al., in: Chemical Kinetic Characterization of the Combustion of Toluene, Proceedings of the Second Joint Meeting of the U.S. Sections of the Combustion Institute , 2001] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai, H. Ozawa, T. Ogura, A. Miyoshi, M. Koshi, W.J. Pitz, Effects of Toluene Addition to Primary Reference Fuel at High Temperature , SAE 2007-01-4104, 2007]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of PRF/toluene mixtures under the wide range of temperatures (500–1700 K) and pressures (2–50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • a kinetic modeling study on the oxidation of primary Reference Fuel toluene mixtures including cross reactions between aromatics and aliphatics
    Proceedings of the Combustion Institute, 2009
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    Abstract A detailed chemical kinetic model for the mixtures of primary Reference Fuel (PRF: n -heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura, Y. Sakai, A. Miyoshi, M. Koshi, P. Dagaut, Energy Fuels 21 (2007) 3233–3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [W.J. Pitz, R. Seiser, J.W. Bozzelli, et al., in: Chemical Kinetic Characterization of the Combustion of Toluene, Proceedings of the Second Joint Meeting of the U.S. Sections of the Combustion Institute , 2001] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai, H. Ozawa, T. Ogura, A. Miyoshi, M. Koshi, W.J. Pitz, Effects of Toluene Addition to Primary Reference Fuel at High Temperature , SAE 2007-01-4104, 2007]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of PRF/toluene mixtures under the wide range of temperatures (500–1700 K) and pressures (2–50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • a kinetic modeling study on the oxidation of primary Reference Fuel toluene mixtures including cross reactions between aromatics and aliphatics
    Presented at: 32nd International Symposium on Combustion Montreal Canada Aug 03 - Aug 08 2008, 2008
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    A detailed chemical kinetic model for the mixtures of Primary Reference Fuel (PRF: n-heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura et al., Energy & Fuels 21 (2007) 3233-3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [Proc. the 2nd Joint Meeting of the U.S. Combust. Institute (2001)] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross-reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai et al, SAE 2007-01-4014 (2007)]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of toluene and PRF/Toluene mixtures under the wide range of temperatures (500-1700 K) and pressures (2-50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • A Kinetic Modeling study on the Oxidation of Primary Reference Fuel?Toluene Mixtures Including Cross Reactions between Aromatics and Aliphatics
    2008
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    A detailed chemical kinetic model for the mixtures of Primary Reference Fuel (PRF: n-heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura et al., Energy & Fuels 21 (2007) 3233-3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [Proc. the 2nd Joint Meeting of the U.S. Combust. Institute (2001)] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross-reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai et al, SAE 2007-01-4014 (2007)]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of toluene and PRF/Toluene mixtures under the wide range of temperatures (500-1700 K) and pressures (2-50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • Modeling of the Oxidation of Primary Reference Fuel in the Presence of Oxygenated Octane Improvers: Ethyl Tert-Butyl Ether and Ethanol
    Energy and Fuels, 2007
    Co-Authors: Teppei Ogura, Akira Miyoshi, Mitsuo Koshi, Yasuyuki Sakai, Philippe Dagaut
    Abstract:

    A detailed chemical kinetic mechanism has been developed for the oxidation of primary Reference Fuel (PRF, mixture of n-heptane and iso-octane) in the presence of ethyl tert-butyl ether (ETBE) or ethanol. The mechanism was validated by comparison with the existing experimental data from shock tubes, a jet-stirred reactor, and a flow reactor. ETBE and ethanol are known as octane number improvers. Enhancement of research octane number (RON) by the addition of ETBE and ethanol to PRF has been measured using a cooperative Fuel research (CFR) engine. Increase in RON was simulated with the present detailed kinetic mechanism by estimating the critical compression ratio (CCR) for autoignition in a motored engine. The correlation curve between CCR and RON was derived by calculating the CCR for PRF whose composition defines the RON. The kinetic model reproduces observed variations in RON by the addition of ETBE and ethanol to PRF. Those additives showed a very similar effect on RON.

Akira Miyoshi - One of the best experts on this subject based on the ideXlab platform.

  • A kinetic modeling study on the oxidation of primary Reference Fuel–toluene mixtures including cross reactions between aromatics and aliphatics
    Proceedings of the Combustion Institute, 2009
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    Abstract A detailed chemical kinetic model for the mixtures of primary Reference Fuel (PRF: n -heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura, Y. Sakai, A. Miyoshi, M. Koshi, P. Dagaut, Energy Fuels 21 (2007) 3233–3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [W.J. Pitz, R. Seiser, J.W. Bozzelli, et al., in: Chemical Kinetic Characterization of the Combustion of Toluene, Proceedings of the Second Joint Meeting of the U.S. Sections of the Combustion Institute , 2001] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai, H. Ozawa, T. Ogura, A. Miyoshi, M. Koshi, W.J. Pitz, Effects of Toluene Addition to Primary Reference Fuel at High Temperature , SAE 2007-01-4104, 2007]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of PRF/toluene mixtures under the wide range of temperatures (500–1700 K) and pressures (2–50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • a kinetic modeling study on the oxidation of primary Reference Fuel toluene mixtures including cross reactions between aromatics and aliphatics
    Proceedings of the Combustion Institute, 2009
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    Abstract A detailed chemical kinetic model for the mixtures of primary Reference Fuel (PRF: n -heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura, Y. Sakai, A. Miyoshi, M. Koshi, P. Dagaut, Energy Fuels 21 (2007) 3233–3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [W.J. Pitz, R. Seiser, J.W. Bozzelli, et al., in: Chemical Kinetic Characterization of the Combustion of Toluene, Proceedings of the Second Joint Meeting of the U.S. Sections of the Combustion Institute , 2001] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai, H. Ozawa, T. Ogura, A. Miyoshi, M. Koshi, W.J. Pitz, Effects of Toluene Addition to Primary Reference Fuel at High Temperature , SAE 2007-01-4104, 2007]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of PRF/toluene mixtures under the wide range of temperatures (500–1700 K) and pressures (2–50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • a kinetic modeling study on the oxidation of primary Reference Fuel toluene mixtures including cross reactions between aromatics and aliphatics
    Presented at: 32nd International Symposium on Combustion Montreal Canada Aug 03 - Aug 08 2008, 2008
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    A detailed chemical kinetic model for the mixtures of Primary Reference Fuel (PRF: n-heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura et al., Energy & Fuels 21 (2007) 3233-3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [Proc. the 2nd Joint Meeting of the U.S. Combust. Institute (2001)] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross-reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai et al, SAE 2007-01-4014 (2007)]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of toluene and PRF/Toluene mixtures under the wide range of temperatures (500-1700 K) and pressures (2-50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • A Kinetic Modeling study on the Oxidation of Primary Reference Fuel?Toluene Mixtures Including Cross Reactions between Aromatics and Aliphatics
    2008
    Co-Authors: Yasuyuki Sakai, Akira Miyoshi, Mitsuo Koshi, William J Pitz
    Abstract:

    A detailed chemical kinetic model for the mixtures of Primary Reference Fuel (PRF: n-heptane and iso-octane) and toluene has been proposed. This model is divided into three parts; a PRF mechanism [T. Ogura et al., Energy & Fuels 21 (2007) 3233-3239], toluene sub-mechanism and cross reactions between PRF and toluene. Toluene sub-mechanism includes the low temperature kinetics relevant to engine conditions. A chemical kinetic mechanism proposed by Pitz et al. [Proc. the 2nd Joint Meeting of the U.S. Combust. Institute (2001)] was used as a starting model and modified by updating rate coefficients. Theoretical estimations of rate coefficients were performed for toluene and benzyl radical reactions important at low temperatures. Cross-reactions between alkane, alkene, and aromatics were also included in order to account for the acceleration by the addition of toluene into iso-octane recently found in the shock tube study of the ignition delay [Y. Sakai et al, SAE 2007-01-4014 (2007)]. Validations of the model were performed with existing shock tube and flow tube data. The model well predicts the ignition characteristics of toluene and PRF/Toluene mixtures under the wide range of temperatures (500-1700 K) and pressures (2-50 atm). It is found that reactions of benzyl radical with oxygen molecule determine the reactivity of toluene at low temperature. Although the effect of toluene addition to iso-octane is not fully resolved, the reactions of alkene with benzyl radical have the possibility to account for the kinetic interactions between PRF and toluene.

  • Modeling of the Oxidation of Primary Reference Fuel in the Presence of Oxygenated Octane Improvers: Ethyl Tert-Butyl Ether and Ethanol
    Energy and Fuels, 2007
    Co-Authors: Teppei Ogura, Akira Miyoshi, Mitsuo Koshi, Yasuyuki Sakai, Philippe Dagaut
    Abstract:

    A detailed chemical kinetic mechanism has been developed for the oxidation of primary Reference Fuel (PRF, mixture of n-heptane and iso-octane) in the presence of ethyl tert-butyl ether (ETBE) or ethanol. The mechanism was validated by comparison with the existing experimental data from shock tubes, a jet-stirred reactor, and a flow reactor. ETBE and ethanol are known as octane number improvers. Enhancement of research octane number (RON) by the addition of ETBE and ethanol to PRF has been measured using a cooperative Fuel research (CFR) engine. Increase in RON was simulated with the present detailed kinetic mechanism by estimating the critical compression ratio (CCR) for autoignition in a motored engine. The correlation curve between CCR and RON was derived by calculating the CCR for PRF whose composition defines the RON. The kinetic model reproduces observed variations in RON by the addition of ETBE and ethanol to PRF. Those additives showed a very similar effect on RON.