This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Investigation into the Influence of Charge Cooling and Autoignition Chemistry on the Greater Knock Resistance of Ethanol over Iso-octane
Technical Paper
2013-01-2615
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
A study was conducted to investigate the relative influence of charge cooling and autoignition chemistry on the greater knock resistance seen by alcohol fuels compared to petrols when operating under “Beyond RON” conditions in a Port Fuel Injection (PFI) engine.
The methodology employed was that of a modelling study calibrated and validated using experimental data, with ethanol and iso-octane used as representatives of the alcohol fuels and petrols respectively. A two zone combustion model combined with an empirical knock model formed the centre of the modelling work, with the experimental investigation conducted on a boosted PFI engine.
The comparison of knock resistance between ethanol and iso-octane showed that autoignition chemistry plays the largest role in the knock resistance advantage of ethanol.
This dominance by autoignition chemistry is partly aided by PFI's poor use of the charge cooling capacity of ethanol. Ethanol may in fact produce an even greater knock resistance advantage over iso-octane in a Direct Injection (DI) engine, where the charge cooling capabilities of ethanol may be better utilised.
Recommended Content
Authors
Citation
Bock, B., Bell, A., and Floweday, G., "Investigation into the Influence of Charge Cooling and Autoignition Chemistry on the Greater Knock Resistance of Ethanol over Iso-octane," SAE Technical Paper 2013-01-2615, 2013, https://doi.org/10.4271/2013-01-2615.Also In
References
- Turner, J., Pearson, R., Holland, B., and Peck, R., “Alcohol-Based Fuels in High Performance Engines,” SAE Technical Paper 2007-01-0056, 2007, doi:10.4271/2007-01-0056.
- Brewster, S., “Initial Development of a Turbo-charged Direct Injection E100 Combustion System,” SAE Technical Paper 2007-01-3625, 2007, doi:10.4271/2007-01-3625.
- Kapus, P., Fuerhapter, A., Fuchs, H., and Fraidl, G., “Ethanol Direct Injection on Turbocharged SI Engines - Potential and Challenges,” SAE Technical Paper 2007-01-1408, 2007, doi:10.4271/2007-01-1408.
- Nakata, K., Utsumi, S., Ota, A., Kawatake, K. et al., “The Effect of Ethanol Fuel on a Spark Ignition Engine,” SAE Technical Paper 2006-01-3380, 2006, doi:10.4271/2006-01-3380.
- Brusstar, M. and Gray, C., “High Efficiency with Future Alcohol Fuels in a Stoichiometric Medium Duty Spark Ignition Engine,” SAE Technical Paper 2007-01-3993, 2007, doi:10.4271/2007-01-3993.
- Petitjean, D., Bernardini, L., Middlemass, C., and Shahed, S., “Advanced Gasoline Engine Turbocharging Technology for Fuel Economy Improvements,” SAE Technical Paper 2004-01-0988, 2004, doi:10.4271/2004-01-0988.
- Hunwartzen, I., “Modification of CFR Test Engine Unit to Determine Octane Numbers of Pure Alcohols and Gasoline-Alcohol Blends,” SAE Technical Paper 820002, 1982, doi:10.4271/820002.
- Heywood J., Internal Combustion Engine Fundamentals, Singapore: McGraw-Hill, 1988.
- Kalghatgi, G., “Fuel Anti-Knock Quality- Part II. Vehicle Studies - How Relevant is Motor Octane Number (MON) in Modern Engines?,” SAE Technical Paper 2001-01-3585, 2001, doi:10.4271/2001-01-3585.
- Kalghatgi, G., “Fuel Anti-Knock Quality - Part I. Engine Studies,” SAE Technical Paper 2001-01-3584, 2001, doi:10.4271/2001-01-3584.
- Mittal, V. and Heywood, J., “The Relevance of Fuel RON and MON to Knock Onset in Modern SI Engines,” SAE Technical Paper 2008-01-2414, 2008, doi:10.4271/2008-01-2414.
- Yates, A., Swarts, A., and Viljoen, C., “Correlating Auto-Ignition Delays And Knock-Limited Spark- Advance Data For Different Types Of Fuel,” SAE Technical Paper 2005-01-2083, 2005, doi:10.4271/2005-01-2083.
- Leppard, W., “The Chemical Origin of Fuel Octane Sensitivity,” SAE Technical Paper 902137, 1990, doi:10.4271/902137.
- Cavaliere A. and de Joannon M., “Mild Combustion,” Progress in Energy and Combustion Science, vol. 30, no. 4, pp. 329-366, 2004.
- Yates, A. and Viljoen, C., “An Improved Empirical Model for Describing Auto-ignition,” SAE Technical Paper 2008-01-1629, 2008, doi:10.4271/2008-01-1629.
- Floweday, G., “A New Functional Global Auto-ignition Model for Hydrocarbon Fuels - Part 1 of 2: An Investigation of Fuel Auto-Ignition Behaviour and Existing Global Models,” SAE Int. J. Fuels Lubr. 3(2):710-724, 2010, doi:10.4271/2010-01-2161.
- Taylor C., Internal Combustion Engine in Theory and Practice: Combustion, Fuels, Materials, Design, MIT Press, 1985.
- Zhao F., Lai M. and Harrington D., “Automotive spark- ignited direct-injection gasoline engines,” Progress in Energy and Combustion Science, vol. 25, no. 5, pp. 437-562, 1999.
- Bock B. D., An investigation into the influence of autoignition chemistry and charge cooling under “Beyond RON” operting conditions on the improved knock resistance of ethanol over iso-octane, Cape Town: University of Cape Town, 2013.
- Annand W. J. D., “Heat transfer in the cylinders of reciprocating internal combustion engines,” Proceedings of the Institution of Mechanical Engineers, vol. 177, no. 36, pp. 973-996, 1963.
- Wu P. C. and Livengood J. C., “Correlation of autoignition phenomena in internal combustion engines and rapid compression machines,” in Symposium Int. On combustion (8th), 1955.
- Yates A. D. B., Bell A. and Swarts A., “Insights relating to the autoignition characteristics of alcohol fuels,” Fuel, vol. 89, pp. 83-93, 2010.
- Swarts, A. and Yates, A., “In-Cylinder Fuel Evaporation and Heat Transfer Information Inferred from the Polytropic Character of the Compression Stroke in a Spark-Ignition Engine,” SAE Technical Paper 2004-01-1856, 2004, doi:10.4271/2004-01-1856.
- Soltis, D., “Evaluation of Cylinder Pressure Transducer Accuracy based upon Mounting Style, Heat Shields, and Watercooling,” SAE Technical Paper 2005-01-3750, 2005, doi:10.4271/2005-01-3750.
- Hohenberg H., “Experimentelle erfassung der wandwärme in kolbenmotoren” (Experimental acquistion of the wall heat in piston engines), Technical University of Graz, 1980.
- AVL, “Engine Indicating User Handbook,” 2002. [Online]. Available: http://www.unipa.it/emiliano.pipitone/_reserved/engine %20pressure%20indicating%20handbook.pdf. [Accessed 07 May 2013].
- Kar, K., Cheng, W., and Ishii, K., “Effects of Ethanol Content on Gasohol PFI Engine Wide-Open-Throttle Operation,” SAE Int. J. Fuels Lubr. 2(1):895-901, 2009, doi:10.4271/2009-01-1907.
- Brown C. and Ladommatos N., “A numerical study of fuel evaporation and transportation in the intake manifold of a port-injected spark-ignition engine,” Journal of Automobile Engineering, vol. 205, no. 34, pp. 161-175, 1991.
- Woschni, G., “A Universally Applicable Equation for the Instantaneous Heat Transfer Coefficient in the Internal Combustion Engine,” SAE Technical Paper 670931, 1967, doi:10.4271/670931.