This content is not included in your SAE MOBILUS subscription, or you are not logged in.
A Study of the Effects of Varying the Supercharging Pressure and Fuel Octane Number on Spark Ignition Engine Knocking using Spectroscopic Measurement and In-cylinder Visualization
Published October 15, 2013 by Society of Automotive Engineers of Japan in Japan
Annotation ability available
Engine downsizing with a turbocharger / supercharger has attracted attention as a way of improving the fuel economy of automotive gasoline engines, but this approach can be frustrated by the occurrence of abnormal combustion. In this study, the factors causing abnormal combustion were investigated using a supercharged, downsized engine that was built by adding a mechanical supercharger. Combustion experiments were conducted in which the fuel octane number and supercharging pressure were varied while keeping the engine speed, equivalence ratio and intake air temperature constant. In the experiments, a visualization technique was applied to photograph combustion in the combustion chamber, absorption spectroscopy was used to investigate the intermediate products of combustion, and the cylinder pressure was measured. The experimental data obtained simultaneously were then analyzed to examine the effects on combustion. The results showed that increasing fuel octane number had effect of moderating combustion by lengthening period from development of a cool flame to occurrence of autoignition. Additionally, increasing the supercharging pressure retarded the onset of the cool flame reactions and advanced the occurrence of autoignition.
CitationIshino, T., Hayakawa, N., Miyasaka, T., Iijima, A. et al., "A Study of the Effects of Varying the Supercharging Pressure and Fuel Octane Number on Spark Ignition Engine Knocking using Spectroscopic Measurement and In-cylinder Visualization," SAE Technical Paper 2013-32-9030, 2013, https://doi.org/10.4271/2013-32-9030.
- Withrow , L. , Rassweiler , G. Slow Motion Shows Knocking and Non-Knocking Explosions SAE Paper 360126
- Nakagawa , Y. , Takagi , Y. , Itoh , T. , Iijima , T. Laser Shadowgraphic Analysis of Knocking in SI Engine SAE Paper 845001 1984
- Hayashi , T. , Taki , M. , Kojima , S. , Kondo , T. Photographic Observation of Knock with a Rapid Compression and Expansion Machine SAE Paper 841336 1984
- Warnatz , J. , Maas , U. , Dibble , R. W. Combustion 3rd 2000 227 236
- Shoji , H. , Saima , A. , Shiino , K. Simultaneous Measurement of Light Emission and Absorption Behavior of Unburned Gas During Knocking Operation SAE Paper 932754 1993
- Iijima , A. , Yoshida , K. , and Shoji , H. A Study of HCCI Combustion using Spectroscopic Techniques and Chemical Kinetic Simulations SAE Int. J. Engines 2 2 721 732 2009 10.4271/2009-32-0070
- Gaydon , A. G. The Spectroscopy of Flame” 2nd 1974 London Chapman and Hall Ltd.