Abstract
<div class="section abstract"><div class="htmlview paragraph">Super-knock has been a significant obstacle for the development of highly turbocharged (downsized) gasoline engines with spark ignition, due to the catastrophic damage super-knock can cause to the engine. According to previous research by the authors, one combustion process leading to super-knock may be described as hot-spot induced pre-ignition followed by deflagration which can induce detonation from another hot spot followed by high pressure oscillation. The sources of the hot spots which lead to pre-ignition (including oil films, deposits, gas-dynamics, etc.) may occur sporadically, which leads to super-knock occurring randomly at practical engine operating conditions. In this study, a spark plasma was used to induce preignition and the correlation between super-knock combustion and the thermodynamic state of the reactant mixture was investigated in a four-cylinder production gasoline engine. The engine experiments were complemented by rapid compression machine (RCM) experiments of iso-octane and air which also used a spark plasma to investigate the fundamental physical and chemical mechanisms of super-knock. For the engine experiments, at low-speed high-load conditions, early spark timing was used to systematically induce preignition in the range of spark timing from 8 to -50 °CA ATDC in increments of 3 °CA. The intake pressure of the fresh air charge was set at 1, 1.3, 1.6 and 1.9 bar, and for each intake air pressure, the intake temperature was set at 20 and 60 °C. The results show early spark ignition could be used to trigger pre-ignition and to induce super-knock when the mixture thermodynamic state was above a critical condition. At a constant air temperature and high intake pressure, advancing the spark timing caused transitions from normal combustion to knocking conditions, to super-knocking conditions and then back to knocking conditions and to normal combustion. The transition between knocking conditions was well correlated with the thermodynamic state at the start of the in-cylinder pressure oscillations associated with knock. At a constant temperature and naturally aspirated conditions, no matter how advanced the spark timing was, only slight knock was observed, which indicates the thermodynamic state dominates the determination of knocking or non-knocking conditions. An energy density-pressure-temperature (E-P-T) diagram was developed to define super-knock, knock and normal combustion criteria. For the RCM experiments using isooctane at stoichiometric conditions with air dilution, a spark plasma was used to simulate pre-ignition. Three compression ratios were used to create different end of compression (EOC) temperatures. For each T<sub>EOC</sub>, with increasing EOC pressure, the combustion process also transitioned from normal combustion with flame propagation, to sequential end-gas auto-ignition with pressure oscillations and then to detonation with severe pressure oscillations. The combustion processes observed in the RCM experiments and the thermodynamic states were similar to the state conditions at the start of the pressure oscillations of the constant temperature and high intake pressure engine experiments. The results indicate RCM studies can be used to investigate the physical and chemical mechanisms of super-knock and E-P-T diagrams can be used to predict and distinguish super-knock from other combustion modes.</div></div>
Topics

No keywords indexed for this article. Browse by subject →

References
39
[1]
Heywood , J.B. Internal combustion engine fundamentals Mcgraw-hill New York 1988
[2]
Liu , H. , Wang , Z. , Long , Y. , and Wang , J. Dual-Fuel Spark Ignition (DFSI) combustion fuelled with different alcohols and gasoline for fuel efficiency Fuel 157 255 260 2015 10.1016/j.fuel.2015.04.042
[3]
Willand , J. , Daniel , M. , Montefrancesco , E. , Geringer , B. , Hofmann , P. , and Kieberger , M. Limits on downsizing in spark ignition engines due to pre-ignition MTZ Worldw. 70 56 61 2009 10.1007/BF03226955 10.1007/bf03226955
[4]
Winklhofer , E. , Hirsch , A. , Kapus , P. , Kortschak , M. et al. TC GDI Engines at Very High Power Density - Irregular Combustion and Thermal Risk SAE Technical Paper 2009-24-0056 2009 10.4271/2009-24-0056 10.4271/2009-24-0056
[5]
Amann , M. , Alger , T. , and Mehta , D. The Effect of EGR on Low-Speed Pre-Ignition in Boosted SI Engines SAE Int. J. Engines 4 1 235 245 2011 10.4271/2011-01-0339 10.4271/2011-01-0339
[6]
Wang , Z. , Liu , H. , Song , T. , Qi , Y. , He , X. , Shuai , S. , and Wang , J. Relationship between super-knock and pre-ignition Int. J. Engine Res. 16 2 166 180 2015 10.1177/1468087414530388 10.1177/1468087414530388
[7]
Bradley , D. , Morley , C. , Gu , X. , and Emerson , D. Amplified Pressure Waves During Autoignition: Relevance to CAI Engines SAE Technical Paper 2002-01-2868 2002 10.4271/2002-01-2868 10.4271/2002-01-2868
[8]
Bradley , D. and Kalghatgi , G.T. Influence of autoignition delay time characteristics of different fuels on pressure waves and knock in reciprocating engines Combust. Flame 156 12 2307 2318 2009 10.1016/j.combustflame.2009.08.003 10.1016/j.combustflame.2009.08.003
[9]
Bansal , G. and Im , H.G. Autoignition and front propagation in low temperature combustion engine environments Combust. Flame 158 11 2105 2112 2011 10.1016/j.combustflame.2011.03.019 10.1016/j.combustflame.2011.03.019
[10]
Dahnz , C. and Spicher , U. Irregular combustion in supercharged spark ignition engines - pre-ignition and other phenomena Int. J. Engine Res. 11 6 485 498 2010 10.1243/14680874JER609 10.1243/14680874jer609
[11]
Wang , Z. , Qi , Y. , He , X. , Wang , J. , Shuai , S. , and Law , C.K. Analysis of pre-ignition to super-knock: Hotspot-induced deflagration to detonation Fuel 144 222 227 2015 10.1016/j.fuel.2014.12.061 10.1016/j.fuel.2014.12.061
[12]
Dahnz , C. , Han , K. , Spicher , U. , Magar , M. et al. Investigations on Pre-Ignition in Highly Supercharged SI Engines SAE Int. J. Engines 3 1 214 224 2010 10.4271/2010-01-0355 10.4271/2010-01-0355
[13]
Zaccardi , J. , Duval , L. , and Pagot , A. Development of Specific Tools for Analysis and Quantification of Pre-ignition in a Boosted SI Engine SAE Int. J. Engines 2 1 1587 1600 2009 10.4271/2009-01-1795 10.4271/2009-01-1795
[14]
Zahdeh , A. , Rothenberger , P. , Nguyen , W. , Anbarasu , M. et al. Fundamental Approach to Investigate Pre-Ignition in Boosted SI Engines SAE Int. J. Engines 4 1 246 273 2011 10.4271/2011-01-0340 10.4271/2011-01-0340
[15]
Amann , M. , Mehta , D. , and Alger , T. Engine Operating Condition and Gasoline Fuel Composition Effects on Low-Speed Pre-Ignition in High-Performance Spark Ignited Gasoline Engines SAE Int. J. Engines 4 1 274 285 2011 10.4271/2011-01-0342 10.4271/2011-01-0342
[16]
Haenel , P. , Seyfried , P. , Kleeberg , H. , and Tomazic , D. Systematic Approach to Analyze and Characterize Pre-ignition Events in Turbocharged Direct-injected Gasoline Engines 2011 10.4271/2011-01-0343 10.4271/2011-01-0343
[17]
Amann , M. and Alger , T. Lubricant Reactivity Effects on Gasoline Spark Ignition Engine Knock SAE Int. J. Fuels Lubr. 5 2 760 771 2012 10.4271/2012-01-1140 10.4271/2012-01-1140
[18]
Inoue , T. , Inoue , Y. , and Ishikawa , M. Abnormal Combustion in a Highly Boosted SI Engine - The Occurrence of Super Knock SAE Technical Paper 2012-01-1141 2012 10.4271/2012-01-1141 10.4271/2012-01-1141
[19]
Sasaki , N. and Nakata , K. Effect of Fuel Components on Engine Abnormal Combustion SAE Technical Paper 2012-01-1276 2012 10.4271/2012-01-1276 10.4271/2012-01-1276
[20]
Wang , Z. , Xu , Y. , and Wang , J. Suppression of super-knock in TC-GDI engine using two-stage injection in intake stroke (TSII) Sci. China Technol. Sci. 57 1 80 85 2013 10.1007/s11431-013-5374-3 10.1007/s11431-013-5374-3
[21]
Peters , N. , Kerschgens , B. , and Paczko , G. Super-Knock Prediction Using a Refined Theory of Turbulence SAE Int. J. Engines 6 2 953 967 2013 10.4271/2013-01-1109 10.4271/2013-01-1109
[22]
Wang , Z. , He , X. , Liu , H. , Qi , Y. , Zhang , P. , and Wang , J. Initiation of detonation in iso-octane/air mixture under high pressure and temperature condition in closed cylinder 25th Int. Colloq. Dyn. Explos. React. Syst. 2015
[23]
Wang , Z. , Liu , H. , He , X. , and Wang , J. The role of shock wave intersection on detonation initiation under engine-like conditions in RCM Internal combustion engines 2015
[24]
Wang , Z. , Liu , H. , Song , T. , Xu , Y. et al. Investigation on Preignition and Super-Knock in Highly Boosted Gasoline Direct Injection Engines SAE Technical Paper 2014-01-1212 2014 10.4271/2014-01-1212 10.4271/2014-01-1212
[25]
Wang , Z. , Qi , Y. , Liu , H. , Long , Y. et al. Experimental Study on Pre-Ignition and Super-Knock in Gasoline Engine Combustion with Carbon Particle at Elevated Temperatures and Pressures SAE Technical Paper 2015-01-0752 2015 10.4271/2015-01-0752 10.4271/2015-01-0752
[26]
Welling , O. , Collings , N. , Williams , J. , and Moss , J. Impact of Lubricant Composition on Low-speed Pre-Ignition SAE Technical Paper 2014-01-1213 2014 10.4271/2014-01-1213 10.4271/2014-01-1213
[27]
Okada , Y. , Miyashita , S. , Izumi , Y. , and Hayakawa , Y. Study of Low-Speed Pre-Ignition in Boosted Spark Ignition Engine SAE Int. J. Engines 7 2 584 594 2014 10.4271/2014-01-1218 10.4271/2014-01-1218
[28]
Lauer , T. , Heiss , M. , Bobicic , N. , Holly , W. , Pritze , S. , and Powertrain , G.M. A Comprehensive Simulation Approach to Irregular Combustion 2014 10.4271/2014-01-1214 10.4271/2014-01-1214
[29]
Zeldovich , Y.B. Regime Classification of an Exothermic Reaction With Nonuniform Initial Conditions Combust. Flame 39 2 211 214 1980 10.1016/0010-2180(80)90017-6 10.1016/0010-2180(80)90017-6
[30]
Gu , X.J. , Emerson , D.R. , and Bradley , D. Modes of reaction front propagation from hot spots Combust. Flame 133 1-2 63 74 2003 10.1016/S0010-2180(02)00541-2 10.1016/s0010-2180(02)00541-2
[31]
Kalghatgi , G.T. and Bradley , D. Pre-ignition and ‘super-knock’ in turbo-charged spark-ignition engines Int. J. Engine Res. 13 4 399 414 2012 10.1177/1468087411431890 10.1177/1468087411431890
[32]
Dai , P. , Chen , Z. , Chen , S. , and Ju , Y. Numerical experiments on reaction front propagation in n-heptane/air mixture with temperature gradient Proc. Combust. Inst. 35 3 3045 3052 2014 10.1016/j.proci.2014.06.102 10.1016/j.proci.2014.06.102
[33]
Qi , Y. , Wang , Z. , Wang , J. , and He , X. Effects of thermodynamic conditions on the end gas combustion mode associated with engine knock Combust. Flame 000 1 10 2015 10.1016/j.combustflame.2015.08.016
[34]
Zheng , Z. , Badawy , T. , Henein , N. , and Sattler , E. Investigation of Physical and Chemical Delay Periods of Different Fuels in the Ignition Quality Tester J. Eng. Gas Turbines Power 135 6 061501 1 2013 10.1115/1.4023607 10.1115/1.4023607
[35]
Zheng , Z. , Badawy , T. , Henein , N. , Sattler , E. , and Johnson , N. Effect of Cetane Improver on Autoignition Characteristics of Low Cetane Sasol IPK Using Ignition Quality Tester 1 J. Eng. Gas Turbines Power 136 8 081505 2014 10.1115/1.4026812 10.1115/1.4026812
[36]
Liu , H. , Wang , Z. , and Wang , J. Methanol-gasoline DFSI (dual-fuel spark ignition) combustion with dual-injection for engine knock suppression Energy 73 686 693 2014 10.1016/j.energy.2014.06.072
[38]
Liu , H. , Wang , Z. , Wang , J. , Wang , M. , and Yang , W. Controlled SSCI With Moderate End-Gas Auto-Ignition for Fuel Economy Improvement and Knock Suppression J. Eng. Gas Turbines Power 137 10 101508 2015 10.1115/1.4030101
[39]
Mansfield , A.B. , Wooldridge , M.S. , Di , H. , and He , X. Low-temperature ignition behavior of iso-octane Fuel 139 79 86 2015 10.1016/j.fuel.2014.08.019 10.1016/j.fuel.2014.08.019
Cited By
14
International Journal of Hydrogen E...
Metrics
14
Citations
39
References
Details
Published
Apr 05, 2016
Vol/Issue
09(3)
Pages
1475-1485
Cite This Article
Hui Liu, Zhi Wang, Margaret Wooldridge, et al. (2016). Highly Turbocharged Gasoline Engine and Rapid Compression Machine Studies of Super-Knock. SAE International Journal of Engines, 09(3), 1475-1485. https://doi.org/10.4271/2016-01-0686