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CFD-Based Assessment of the Effect of End-Gas Temperature Stratification on Acoustic Knock Generation in an Ultra-Lean Burn Spark Ignition Engine
Technical Paper
2023-01-0250
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
End-gas temperature stratification has long been studied with respect to its effect on stoichiometric spark-ignition (SI) engine knock. The role of temperature stratification for homogeneous-charge compression ignition (HCCI) engine operation is also reasonably well understood. However, the role of temperature stratification in ultra-lean SI engines has had less coverage. Literature is lacking well-controlled studies of how knock is affected by changes in the full cylinder temperature fields, especially since cycle-to-cycle variability can impede a determination of cause and effect. In this work, the knocking propensity of specific cylinder conditions is investigated via 3D computational fluid dynamics (CFD) simulations utilizing a large eddy simulation (LES) framework. The end-gas temperature stratification is systematically varied such that all other parameters remain relatively constant (including the flow field, thereby avoiding cycle-to-cycle variability) allowing for direct conclusions to be drawn. It is found that a substantial paradigm shift in acoustic knock generation is brought on by having large volumes in the end-gas being under a stratification limit set by the time it takes for an acoustic wave to traverse the cylinder domain. Hence, it is shown that temperature stratification of the end gas plays a key role, enabling the combustion system to accept some degree of end-gas autoignition without inducing unwanted acoustic knock.
Authors
Citation
Strickland, T., Sjöberg, M., Matsubara, N., Kitano, K. et al., "CFD-Based Assessment of the Effect of End-Gas Temperature Stratification on Acoustic Knock Generation in an Ultra-Lean Burn Spark Ignition Engine," SAE Technical Paper 2023-01-0250, 2023, https://doi.org/10.4271/2023-01-0250.Also In
References
- Splitter , D.A. and Reitz , R.D. Fuel Reactivity Effects on the Efficiency and Operational Window of Dual-Fuel Compression Ignition Engines Fuel 118 2014 163 175 10.1016/j.fuel.2013.10.045
- Reitz , R.D. Directions in Internal Combustion Engine Research Combustion and Flame 160 1 2013 1 8 10.1016/j.combustflame.2012.11.002
- Ayala F.A. , Heywood J.B. Lean SI Engines: The Role of Combustion Variability in Defining Lean Limits 8th International Conference on Engines for Automobiles Consiglio Nazionale delle Ricerche 2007 10.4271/2007-24-0030
- Hu , Z. , Zhang , J. , Sjöberg , M. , and Zeng , W. The Use of Partial Fuel Stratification to Enable Stable Ultra-Lean Deflagration-Based Spark-Ignition Engine Operation with Controlled End-Gas Autoignition of Gasoline and E85 International Journal of Engine Research 21 9 2020 1678 1695 10.1177/ 1468087419889702
- Singh , E. , Vuilleumier , D. , Kim , N. , and Sjöberg , M. Influence of Gasoline Fuel Formulation on Lean Autoignition in a Mixed-Mode-Combustion (Deflagration/Autoignition) Engine Combustion and Flame 242 2022 112163 10.1016/j.combustflame.2022.112163
- Kim , N. , Vuilleumier , D. , Singh , E. , and Sjöberg , M. Octane Requirements of Lean Mixed-Mode Combustion in a Direct-Injection Spark-Ignition Engine Energy & Fuels 36 17 2022 10096 10109 10.1021/acs.energyfuels.2c01794
- Xu C. , Som S. , Sjöberg C.M.G. Large Eddy Simulation of Lean Mixed-Mode Combustion Assisted by Partial Fuel Stratification in a Spark-Ignition Engine 10.1115/1.4050588
- Sjöberg , M. and Dec , J.E. Effects of Engine Speed, Fueling Rate, and Combustion Phasing on the Thermal Stratification Required to Limit hcci Knocking Intensity SAE Transactions 114 2005 1472 1486 10.4271/2006-01-0629
- Bradley D. , Morley C. , Gu X.J. , Emerson D.R. Amplified Pressure Waves During Autoignition: Relevance to Cai Engines SAE Powertrain & Fluid Systems Conference & Exhibition SAE International 2002 10.4271/2002-01-2868
- Kalghatgi , G.T. and Bradley , D. Pre-Ignition and ‘Super-Knock’ in Turbo-Charged Spark-Ignition Engines International Journal of Engine Research 13 4 2012 399 414 10.1177/1468087411431890
- Gu , X. , Emerson , D. , and Bradley , D. Modes of Reaction Front Propagation from Hot Spots Combustion and Flame 133 1 2003 63 74 10.1016/S0010-2180(02)00541-2
- Cho , S. , Lopez-Pintor , D. , and Sofianopoulos , A. A Skeletal Mechanism for Gasoline Surrogates: Development, Validation, and cfd Application Fuel 332 2023 126236 10.1016/j.fuel.2022.126236
- Richards , K. , Senecal , P. , and Pomraning , E. Converge Manual (version 3.0) Madison, WI, USA Convergent Science Inc. 2020 260
- Pomraning , E. , Richards , K. , and Senecal , P.K. Modeling Turbulent Combustion using a Rans Model, Detailed Chemistry, and Adaptive Mesh Refinement SAE International 2014 10.4271/2014-01-1116
- Guleria , G. , Lopez-Pintor , D. , Dec , J.E. , and Assanis , D. A Comparative Study of Gasoline Skeletal Mechanisms under Partial Fuel Stratification Conditions Using Large Eddy Simulations International Journal of Engine Research 23 2021 1658 1677 10.1177/14680874211031370
- Desantes J. , Oliver J.A. , Novella R. , Pastor J. , Shang W. , Bensalem C. , Lopez-Pintor D. Application of a Coupled Eulerian Spray Approach and a Flamelet-Based Combustion Model to Single Hole Primary Reference Fuel Sprays 2020
- DRAPER , C.S. Pressure waves accompanying detonation in the internal combustion engine Journal of the Aeronautical Sciences 5 6 1938 219 226 10.2514/8.590
- Pla , B. , De la Morena , J. , Bares , P. , and Jimenez , I. Knock Analysis in the Crank Angle Domain for Low-Knocking Cycles Detection 2020 10.4271/2020-01-0549
- He , X. , Qi , Y. , Wang , Z. , Wang , J. et al. Visualization of the mode shapes of pressure oscillation in a cylindrical cavity Combustion Science and Technology 187 10 2015 1610 1619 10.1080/00102202.2015.1038385
- Liu , H. , Wang , Z. , Wooldridge , M. , Fatouraie , M. et al. Highly Turbocharged Gasoline Engine and Rapid Compression Machine Studies of Super-Knock SAE International Journal of Engines 9 3 2016 1475 1485 10.4271/2016-01-0686
- Dec , J.E. A Computational Study of the Effects of Low Fuel Loading and egr on Heat Release Rates and Combustion Limits in hcci Engines SAE International 2002 10.4271/2002-01-1309