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Ignition Quality Tester Guided Improvements to Reaction Mechanisms for n-Alkanes: n-Heptane to n-Hexadecane
Technical Paper
2012-01-0149
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
While most published detailed reaction mechanisms for n-alkanes have been validated against shock-tube data that use pre-vaporized fuels, they have not been tested extensively using engine conditions. This is partly due to the complications of the effects of both spray and evaporation on ignition and on the gas-phase kinetics. In this study, CFD simulations of Ignition Quality Tests (IQT™) are used as a tool to validate the detailed reaction mechanisms, supplementing other validation tests that use more fundamental shock-tube data. The Ignition Quality Tester is a new ASTM standard for measuring the Cetane Number (CN) of fuels. Shock-tube data in the literature are limited for heavy n-alkanes of interest for engine fuels, which make CN data valuable for mechanism validation. The IQT employs a stationary combustion chamber that involves spray evaporation and mixing followed by combustion. These processes also play an important role under engine-like conditions, but they are not tested by fundamental experiments. To capture the fuel chemistry accurately in these simulations, we have used the FORTÉ CFD Simulation Package to model the IQT, which allows us to employ detailed reaction mechanisms with hundreds of chemical species and thousands of reaction steps. This work focuses on long-chain alkanes from n-heptane (C₇) to n-hexadecane (C₁₆). n-Alkanes are present in diesel and gasoline fuels, and are key components to their associated reference fuels and model surrogates. Characteristic of high Cetane Number (CN) fuel components, they both ignite earlier than most other classes of components and control the onset of ignition in a wide variety of engine configurations. Accurate reaction mechanisms for n-alkanes are therefore necessary to capture the ignition location in engine simulations. Ignition times for n-alkanes from C₇ to C₁₆ in the IQT simulations using the initial mechanism and based on previously published work indicated a contradictory trend in ignition times, with n-hexadecane exhibiting slower ignition than n-heptane. Based on the IQT simulations and other fundamental data, we have updated the detailed mechanism for long-chain n-alkanes by updating the rate rules pertaining particularly to the low-temperature kinetics that is relevant for IQT conditions. The updated reaction mechanism accurately predicts the correct trend in the ignition time in IQT simulations as expected by the corresponding CN of n-alkanes. Although the predicted ignition times in IQT are semi-quantitative, the current work presents an important first step towards using IQT as a tool for validation of reaction mechanisms under more engine-relevant conditions than the fundamental experiments, which is important for establishing confidence in kinetics models for simulating advanced engines using complex fuels.
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Naik, C., Puduppakkam, K., Meeks, E., and Liang, L., "Ignition Quality Tester Guided Improvements to Reaction Mechanisms for n-Alkanes: n-Heptane to n-Hexadecane," SAE Technical Paper 2012-01-0149, 2012, https://doi.org/10.4271/2012-01-0149.Also In
References
- Allard, L. Webster, G. Ryan, T. Matheaus, A. et al. “Diesel Fuel Ignition Quality as Determined in the Ignition Quality Tester (IQTTM) - Part IV,” SAE Technical Papers, 2001-01-3527 2001 10.4271/2001-01-3527
- Bogin, G. E. Jr DeFilippo, A. Chen, J. Y. Chin, G. Luecke, J. Ratcliff, M. A. Zigler, B. T. Dean, A. M. “Modeling the Fuel Spray and Combustion Process of the Ignition Quality Tester™ with KIVA-3V,” Fall Meeting of the Western States Section of the Combustion Institute Irvine, CA 2009
- Knothe, G. Matheaus, A. C. Ryan, T. W. “Cetane numbers of branched and straight-chain fatty esters determined in an ignition quality tester,” Fuel 82 971 975 2003
- FORTÉ CFD Simulation Package: Reaction Design 2011
- Liang, L. Naik, C. Puduppakkam, K. Wang, C. et al. “Efficient Simulation of Diesel Engine Combustion Using Realistic Chemical Kinetics in CFD,” SAE Technical Paper 2010-01-0178 2010 10.4271/2010-01-0178
- Naik, C. Puduppakkam, K. Wang, C. Kottalam, J. “Applying Detailed Kinetics to Realistic Engine Simulation: the Surrogate Blend Optimizer and Mechanism Reduction Strategies,” SAE Int. J. Engines 3 1 241 259 2010 10.4271/2010-01-0541
- Murphy, M. J. Taylor, J. D. McCormick, R. L. “Compendium of Experimental Cetane Number Data,” National Renewable Energy Laboratory 2004
- Kong, S.-C. Reitz, R. D. “Use of Detailed Chemical Kinetics to Study HCCI Engine Combustion With Consideration of Turbulent Mixing Effects,” Transactions of the ASME 124 702 707 2002
- FORTÉ CFD Simulation Package: Theory Manual: Reaction Design 2011
- Abani, N. Kokjohn, S. Park, S. Bergin, M. et al. “An Improved Spray Model for Reducing Numerical Parameter Dependencies in Diesel Engine CFD Simulations,” SAE Technical Papers, 2008-01-0970 2008 10.4271/2008-01-0970
- Wang, Y. Ge, H. Reitz, R. “Validation of Mesh- and Timestep- Independent Spray Models for Multi-Dimensional Engine CFD Simulation,” SAE Int. J. Fuels Lubr. 3 1 277 302 2010 10.4271/2010-01-0626
- Westbrook, C. K. Pitz, W. Herbinet, O. Curran, H. J. Silke, E. J. “A Detailed Chemical Kinetic Reaction Mechanism for Combustion of n-Alkanes from n-Octane to n-Hexadecane,” Comb. Flame 156 181 191 2009
- Puduppakkam, K. Naik, C. Wang, C. Meeks, E. “Validation Studies of a Master Kinetic Mechanism for Diesel and Gasoline Surrogate Fuels,” SAE Technical Paper 2010-01-0545 2010 10.4271/2010-01-0545
- Puduppakkam, K. Liang, L. Naik, C. Meeks, E. Bunting, B. “Combustion and Emissions Modeling of an HCCI Engine Using Model Fuels,” SAE Technical Papers, 2009-01-0669 2009 10.4271/2009-01-0669
- CHEMKIN-PRO 15101, San Diego: Reaction Design 2010
- Lu, T. Law, C. K. “On the applicability of directed relation graphs to the reduction of reaction mechanisms,” Combustion and Flame 146 472 483 2006
- Liang, L. Stevens, J. G. Farrell, J. T. “A Dynamic Adaptive Chemistry Scheme for Reactive Flow Computations,” Proc. Comb. Inst. 32 527 534 2009
- Reaction Workbench with CHEMKIN-PRO: Reaction Design 2011
- Liang, L. Stevens, J. G. Farrell, J. T. “A dynamic multi-zone partitioning scheme for solving detailed chemical kinetics in reactive flow calculations,” Comb. Sci. Tech. 181 1345 1371 2009
- Naik, C. Puduppakkam, K. Meeks, E. “Modeling the Detailed Chemical Kinetics of NOx Sensitization for the Oxidation of a Model fuel for Gasoline,” SAE Int. J. Fuels Lubr. 3 1 556 566 2010 10.4271/2010-01-1084
- Naik, C. V. Westbrook, C. K. Herbinet, O. Pitz, W. J. Mehl, M. “Detailed Chemical Kinetic Reaction Mechanism for Biodiesel Components Methyl Stearate and Methyl Oleate,” Proc. Comb. Inst. 33 383 389 2011
- Westbrook, C. K. Naik, C. V. Herbinet, O. Pitz, W. J. Mehl, M. Sarathy, S. M. Curran, H. J. “Detailed chemical kinetic reaction mechanisms for soy and rapeseed biodiesel fuels,” Comb. Flame 158 742 755 2011
- Naik, C. V. Puduppakkam, K. V. Meeks, E. “An Improved Core Reaction Mechanism for Saturated C0-C4 Fuels,” J. Eng. Gas Turbines Power 134 2012
- Naik, C. V. “Detailed Chemical Kinetic Modeling of Decalin Combustion,” 7th US National Technical Meeting of the Combustion Institute Atlanta, GA 2011 RK76
- Naik, C. V. Puduppakkam, K. V. Meeks, E. “An Improved Core Reaction Mechanism for Un-saturated C0-C4 Fuels and their Blends,” Proc. ASME Turbo Expo 2012
- Westbrook, C. K. Pitz, W. Herbinet, O. Curran, H. J. Silke, E. J. “A Detailed Chemical Kinetic Reaction Mechanism for Combustion of n-Alkanes from n-Octane to n-Hexadecane,” Combustion and Flame 156 181 191 2009
- Villano, S. M. Huyn, L. K. Carstensen, H.-H. Dean, A. M. “Detailed Modeling of Low-Temperature Alkane Oxidation: High-Pressure Rate Rules for Alkyl+O2 Reactions,” 7th US National Technical Meeting of the Combustion Institute Atlanta, GA 2011
- Carstensen, H.-H. Naik, C. V. Dean, A. M. “Detailed Modeling of the Reaction of C2H5 + 02,” J. Phys. Chem. A 109 2264 2281 2005
- Shen, H.-P. S. Steinberg, J. Vanderover, J. Oehlschlaeger, M. A. “A Shock Tube Study of the Ignition of n-Heptane, n-Decane, n-Dodecane, and n-Tetradecane at Elevated Pressures,” Energy & Fuels 23 2482 2489 2009
- Ciezki, H. K. Adomeit, G. “Shock-Tube investigation of self-ignition of n-heptane-air mixtures under engine relevant conditions,” Combustion and Flame 93 421 433 1993
- Gauthier, B. M. Davidson, D. F. Hanson, R. K. “Shock tube determination of ignition delay times in full-blend and surrogate fuel mixtures,” Combustion and Flame 139 300 311 2004
- Herzler, J. Jerig, L. Roth, P. “Shock tube study of the inition of lean n-heptane/air mixtures at intermediate temperatures and high pressures,” Proc. Comb. Inst. 30 1147 1153 2005
- Pfahl, U. Fieweger, K. Adomeit, G. “Self-ignition of diesel-relevant hydrocarbon-air mixtures under engine conditions,” Proc. Comb. Inst. 26 781 789 1996
- Zhukov, V. P. Sechenov, V. A. Starikovskii, A. Y. “Autoignition of n-decane at high pressure,” Combustion and Flame 153 130 136 2008
- Vasu, S. S. Davidson, D. F. Hong, Z. Vasudevan, V. Hanson, R. K. “n-Dodecane oxidation at high pressures: Measurements of ignition delay times and OH concentration time histories,” Proc. Combust. Inst. 32 173 180 2009