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Multi-Cycle Large Eddy Simulation (LES) of the Cycle-to-Cycle Variation (CCV) of Spark Ignition (SI) - Controlled Auto-Ignition (CAI) Hybrid Combustion in a Gasoline Engine
Technical Paper
2017-01-2261
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
The spark ignition (SI) - controlled auto-ignition (CAI) hybrid combustion, also known as spark-assisted compression ignition (SACI), is achieved by utilizing the temperature and pressure rise from the early flame propagation induced by the spark-ignition to trigger the auto-ignition of the remaining unburned mixture. This hybrid combustion concept can be used to effectively extend the operating range of gasoline CAI combustion and achieve smooth transitions between SI and CAI combustion mode in gasoline engines. However, the significant cycle-to-cycle variation (CCV) of the SI-CAI hybrid combustion hinders the practical application of the hybrid combustion. In order to understand the cause of its high CCVs, the SI-CAI hybrid combustion process in a gasoline engine was studied in this study by the large eddy simulations (LES). The turbulence is modelled by the sub-grid k model. The spark ignition and subsequent flame propagation were modelled by the ECFM-3Z LES model. A tabulated database of the gasoline auto-ignition chemistry was coupled with the CFD simulations to depict the subsequent auto-ignition process of the unburned mixture after the initiation of flame propagation. The LES simulation was validated and applied to analyze the hybrid combustion process in a single cylinder engine at 1500 rpm and 5.43 bar IMEP, which was characterized with a coefficient of variation (COV) of 11.81% in IMEP. The LES simulations of 15 consecutive cycles were performed and analyzed to evaluate the potential of LES simulations to predict the CCV of SI-CAI hybrid combustion. The analysis of the LES simulation results indicates that the average thermal and compositional parameters are not the main reason for the cycle-to-cycle variations of the SI-CAI hybrid combustion. The temperature and residual gas fraction (RGF) in the spark zone is also very stable among different cycles. In comparison, the average velocity in the whole cylinder reduces from 7.8 m/s in the strong combustion cycle (Cycle 11) to 6.4 m/s in the weakest combustion cycle (Cycle 14) with 21.9% reduction, and the average velocity in the spark zone reduces from 6.3 m/s to 3.8 m/s with 60.3% reduction. Therefore, the variations of the in-cylinder flow velocity, especially around the spark plug, could be the main reason for the large variations of the hybrid combustion observed in the experiments.
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Citation
Wang, X. and Zhao, H., "Multi-Cycle Large Eddy Simulation (LES) of the Cycle-to-Cycle Variation (CCV) of Spark Ignition (SI) - Controlled Auto-Ignition (CAI) Hybrid Combustion in a Gasoline Engine," SAE Technical Paper 2017-01-2261, 2017, https://doi.org/10.4271/2017-01-2261.Data Sets - Support Documents
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References
- Zhao , H. HCCI and CAI engines for the automotive industry 2007 Cambridge, England Woodhead Publishing
- Xie , H. , Yang , L. , Qin , J. , Gao , R. et al. The Effect of Spark Ignition on the CAI Combustion Operation SAE Technical Paper 2005-01-3738 2005 10.4271/2005-01-3738
- Wang , Z. , Wang , J. , Shuai , S. , and Ma , Q. Effects of Spark Ignition and Stratified Charge on Gasoline HCCI Combustion With Direct Injection SAE Technical Paper 2005-01-0137 2005 10.4271/2005-01-0137
- Chen , T. , Xie , H. , Li , L. , Yu , W. et al. Continuous Load Adjustment Strategy of a Gasoline HCCI-SI Engine Fully Controlled by Exhaust Gas SAE Technical Paper 2011-01-1408 2011 10.4271/2011-01-1408
- Milovanovic , N. , Blundell , D. , Gedge , S. , and Turner , J. SI-HCCI-SI Mode Transition at Different Engine Operating Conditions SAE Technical Paper 2005-01-0156 2005 10.4271/2005-01-0156
- Santoso , H. , Matthews , J. , and Cheng , W. Managing SI/HCCI Dual-Mode Engine Operation SAE Technical Paper 2005-01-0162 2005 10.4271/2005-01-0162
- Zhang , Y. , Xie H. and Zhao H. Investigation of SI-HCCI Hybrid Combustion and Control Strategies for Combustion Mode Switching in a Four-Stroke Gasoline Engine Combust. Sci. and Tech 2009 181 782 799
- Manofsky , L. , Vavra , J. , Assanis , D. , and Babajimopoulos , A. Bridging the Gap between HCCI and SI: Spark-Assisted Compression Ignition SAE Technical Paper 2011-01-1179 2011 10.4271/2011-01-1179
- Chen , T. et al. Analysis of cyclic variations during mode switching between spark ignition and controlled auto-ignition combustion operations International Journal of Engine Research 2015 16 3 356 365
- Wagner , R. , Edwards , K. , Daw , C. , Green , J. et al. On the Nature of Cyclic Dispersion in Spark Assisted HCCI Combustion SAE Technical Paper 2006-01-0418 2006 10.4271/2006-01-0418
- Daw , C.S. et al. Understanding the transition between conventional spark-ignited combustion and HCCI in a gasoline engine Proceedings of the Combustion Institute 31 2007 31 2887 2894
- Sen , A.K. et al. Characteristics of cyclic heat release variability in the transition from spark ignition to HCCI in a gasoline engine Applied Energy 2012 88 1649 1655
- Larimore , J. et al. Experiments and Analysis of High Cyclic Variability at the Operational Limits of Spark-Assisted HCCI Combustion 2012 American Control Conference (ACC) 2012; 12_ACCb 2072 2077
- Temel , V. and Sterniak , J. Characterization of SACI Combustion for Use in Model Based Controls SAE Technical Paper 2014-01-1289 2014 10.4271/2014-01-1289
- Havstad , M. , Aceves , S. , McNenly , M. , Piggott , W. et al. Detailed Chemical Kinetic Modeling of Iso-octane SI-HCCI Transition SAE Technical Paper 2010-01-1087 2010 10.4271/2010-01-1087
- Joelsson , T. , Yu R. and Bai X.S. Large Eddy Simulation of Turbulent Combustion in a Spark-Assisted Homogenous Charge Compression Ignition Engine Combustion Science and Technology 2012 184 1051 1065
- Yoo , C.S. et al. A DNS study of ignition characteristics of a lean iso-octane/air mixture under HCCI and SACI conditions Proceedings of the Combustion Institute 2013 34 2 2985 2993
- Wang , X. et al. Effect of the Thermal Stratification on SI-CAI Hybrid Combustion in a Gasoline Engine Applied Thermal Engineering 2013 61 2 451 460
- Wang , X. , Xie , H. , Li , L. , Xie , L. et al. Wall Temperature Effect on SI-CAI Hybrid Combustion Progress in a Gasoline Engine SAE Technical Paper 2013-01-1662 2013 10.4271/2013-01-1662
- Wang , X. et al. Numerical simulation and validation of SI-CAI hybrid combustion in a CAI/HCCI gasoline engine Combustion Theory and Modelling 2013 17 1 142 166
- Wang , X. , Xie H. and Zhao H. Computational study of the influence of in-cylinder flow on spark ignition-controlled autoignition hybrid combustion in a gasoline engine International Journal of Engine Research 2015 16 5 795 809
- Wang , X. , Zhao H. and Xie H. Effect of piston shapes and fuel injection strategies on stoichiometric stratified flame ignition (SFI) hybrid combustion in a PFI/DI gasoline engine by numerical simulations Energy Conversion and Management 2015 98 0 387 400
- Wang , X. , Zhao H. and Xie H. Effect of dilution strategies and direct injection ratios on Stratified Flame Ignition (SFI) hybrid combustion in a PFI/DI gasoline engine Applied Energy 2016 165 801 814
- Speziale , C.G. Analytical methods for the development of Reynolds-stress closures in turbulence Annual Review of Fluid Mechanics 1991 23 1 107 157
- Cd-adapco, Methodology, STAR-CD VERSION 4.14, 2010 2010
- Vermorel , O. et al. Towards the understanding of cyclic variability in a spark ignited engine using multi-cycle LES Combustion and Flame 2009 156 8 1525 1541
- Colin , O. and Benkenida A. The 3-Zones Extended Coherent Flame Model (ECFM3Z) for Computing Premixed/Diffusion Combustion Oil & Gas Science and Technology 2004 59 6 593 609
- CRUZ , A.P.D. Three-dimensional modeling of self-ignition in HCCI and conventional diesel engines Combustion Science and Technology 2004 176 5-6 867 887
- Mehl , M. et al. An approach for formulating surrogates for gasoline with application towards a reduced surrogate mechanism for CFD engine modeling Energy & Fuels 2011 25 11 5215 5223
- Pope , S.B. Ten questions concerning the large-eddy simulation of turbulent flows New journal of Physics 2004 6 1 35
- Vermorel , O. et al. Towards the understanding of cyclic variability in a spark ignited engine using multi-cycle LES Combustion and Flame 2009 156 1525 1541
- Colin , O. and Truffin K. A spark ignition model for large eddy simulation based on an FSD transport equation (ISSIM-LES) Proceedings of the Combustion Institute 2011 33 3097 3104