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Fuel Anti-Knock Quality - Part I. Engine Studies
Technical Paper
2001-01-3584
ISSN: 0148-7191, e-ISSN: 2688-3627
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Sector:
Event:
SAE 2002 World Congress & Exhibition
SAE International Fall Fuels & Lubricants Meeting & Exhibition
Language:
English
Abstract
This is the first part of a two-part study on how to define the anti-knock quality of practical fuels. Knock intensity is measured in two single-cylinder research engines using different fuels at different mixture strengths, throttle settings and two compression ratios. The anti-knock quality of a fuel in a given engine operating condition is defined by its octane index OI = RON - KS where K is a constant for that condition and S is the sensitivity, (RON-MON), and RON and MON are the Research and Motor Octane numbers respectively. The higher the octane index, the better the anti-knock quality of the fuel. K is often assumed to be 0.5 so that OI=(RON+MON)/2. However, it is found that K depends on engine operating conditions and in some cases, K is negative so that for a given RON, a fuel with higher sensitivity (lower MON) has better anti-knock quality. The value of K decreases as the engine becomes more prone to knock i.e. as its octane requirement increases. In terms of the end-gas properties, K decreases as the temperature decreases for a given pressure.
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Citation
Kalghatgi, G., "Fuel Anti-Knock Quality - Part I. Engine Studies," SAE Technical Paper 2001-01-3584, 2001, https://doi.org/10.4271/2001-01-3584.Also In
References
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