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Relevance of Research and Motor Octane Numbers to the Prediction of Engine Autoignition
Technical Paper
2004-01-1970
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Links between the RON, MON and Octane Index (OI) of a gasoline are explored and factors influencing knock severity are discussed. The OI was calculated by considering how the autoignition delay time changes with temperature and pressure. Three fuels were examined: a 65/35% toluene/heptane test fuel, and two primary reference fuels (PRF), one with the RON value of the test fuel and the other with the MON value.
PRF autoignition times were taken from Adomeit et al and test fuel autoignition times were generated from mathematical models of RON/MON tests plus two experimental sets of engine autoignition data. The toluene/heptane OI depended strongly on engine conditions and could easily exceed the RON. With a lean mixture at high pressure it was 100.2 whereas the RON was only 83.9.
Knock severity is governed by the nature of localized “hot spots”. Severe knock is associated with developing detonations towards the end of the delay time. An attempt is made to identify the conditions under which these arise.
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Citation
Bradley, D., Morley, C., and Walmsley, H., "Relevance of Research and Motor Octane Numbers to the Prediction of Engine Autoignition," SAE Technical Paper 2004-01-1970, 2004, https://doi.org/10.4271/2004-01-1970.Also In
References
- Kalghatgi, G. T. “Fuel anti-knock quality - Part 1. Engine Studies,” SAE paper 2001-01-3584 2001
- Leppard, W. R. “The chemical origin of fuel octane sensitivity,” SAE paper 902137 1990
- Edgar, G. “Measurement of knock characteristics of gasoline in terms of standard fuel,” Ind. Eng. Chem. 19 145 1927
- American Society for Testing Materials Standard Test Method for Research Octane Number of Spark-Ignition Engine Fuel 2001
- American Society for Testing Materials Standard Test Method for Motor Octane Number of Spark-Ignition Engine Fuel 2001
- Bradley, D. Morley, C. 35 Low-temperature combustion and autoignition Pilling M. J. Comprehensive Chemical Kinetics Compton R. G. Hancock G. Elsevier, Amsterdam 1997
- Karim, G. A. Watson, H. C. “Experimental and computational considerations of the compression ignition of homogeneous fuel-oxidant mixtures,” SAE Trans 80 450 1971
- Leppard, W. R. “A detailed study of chemical kinetics simulation of engine knock,” Combust. Sci. Tech. 43 1 20 1985
- Ciezki, H. K. Adomeit, G. “Shock-tube investigation of self-ignition of n-heptane-air mixtures under engine relevant conditions,” Combust. Flame 93 421 433 1993
- Fieweger, K. Blumenthal, R. “Self-igntion of S.I. engine model fuels: a shock tube investigation at high pressure,” Combust. Flame 109 599 619 1997
- Peters, N. Paczko, G. Seiser, R. “Temperature cross-over and non-thermal runaway at two-stage igntion of n- heptane,” Combust. Flame 128 38 59 2002
- Curran, H. J. Gaffuri, P. Pitz, W. J. Westbrook, C. “A comprehensive modeling study of iso-octane oxidation,” Combust. Flame 129 253 280 2002
- Curran, H. J. Gaffuri, P. Pitz, W. J. Westbrook, C. “A comprehensive modeling study of n-heptane oxidation,” Combust. Flame 114 149 177 1998
- Douaud, A. M. Eyzat, P. “Four-Octane-Number method for predicting the anti-knock behavior of fuels and engines,” SAE paper 780080 SAE Trans. 87 1978
- Kalghatgi, G. Risberg, P Ångstrom, H.-E. “A method of defining ignition quality of fuels in HCCI engines,” SAE paper 2003-01-1816 and JSAE 20030120 2003
- Hirst, S. L. Kirsch, L. J. “The Application of a Hydrocarbon Autoignition Model in Simulating Knock and Other Engine Combustion Phenomena,” in Combustion Modeling in Reciprocating Engines Mattavi J. N. Amann C. A. Plenum Publishing New York 1980
- Kelly-Zion, P. L. Dec, J. E. “A computational study of the effect of fuel type on ignition time in homogeneous charge compression ignition engines,” Proc. Combust. Inst. 28 1187 1194 2000
- Risberg, P. Kalghatgi, G. Angstrom, H.-E. “Auto-ignition quality of gasoline-like fuels in HCCI engines,” SAE paper 2003-01-3215 2003
- Bradley, D. Morley, C. Gu, X. J. Emerson, D.R. “Amplified pressure waves during autoignition: relevance to CAI engines,” SAE paper 2002-01-2868 2002
- Nygren, J. Hult, J. Richter, M Aldén. M. Christensen, M. Hultqvist, A. Johannson, B. “Three-dimensional laser induced fluorescence of fuel distributions in an HCCI engine,” Proc. Combust. Inst. 29 679 685 2002
- Schießl, R. Maas, U. “Analysis of end gas temperature fluctuations in an SI engine by laser-induced fluorescence (LIF),” Combust. Flame 133 19 27 2003
- Tanaka, S. Ayala, F. Keck, J. C. Heywood, J. B. “Two-stage ignition in HCCI combustion and HCCI control by fuel and additives,” Combust. Flame 132 219 239 2003
- Bradley, D. Gu, X. J. Emerson, D. R. “Modes of reaction front propagation from hot spots in flammable gaseous premixtures “Fourth International Seminar on Fire and Explosion Hazards,” Londonderry 2003
- Oakley, A. Zhao, H. Ladommatos, N. “Dilution effects on the controlled auto-ignition (CAI) combustion of hydrocarbon and alcohol fuels,” SAE paper 2001 2001-01-3606