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Evaluation of the Effect of EGR on Engine Knock
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 19, 1998 by SAE International in United States
Annotation ability available
The effect of external EGR on knock was evaluated using a CFR engine. Combustion pressure was sampled on a time basis. A band pass filter in the time domain was applied to the pressure cycles. Five knock indices were calculated for each combustion cycle.
The problem to quantify knock intensity was focused. At this extent measurements were carried out on standard isooctane-n-heptane blends in the test conditions used for the determination of the Motor Method Octane Number (MON). Knock intensity was varied acting on compression ratio.
For each index, the conditions of absence of knock were determined using motored cycles. The indices were compared and one of them, showing the lowest C.O.V., was selected for further measurements.
The effect of EGR on test fuels having different composition was evaluated varying the compression ratio, at fixed ignition timing. In this way, the same level of detonation, obtained in the absence of EGR, was realized with different amount of external EGR. Percent variation of compression ratio was used to compare the ability of fuels, having different octane number, to tolerate compression ratio increase in presence of EGR.
In particular the tests were carried out on a matrix of twelve fuels with three levels of EGR. The result show that with all tested fuels the percent increase of compression ratio is strongly dependent on EGR.
|Journal Article||EGR Effects on Boosted SI Engine Operation and Knock Integral Correlation|
|Technical Paper||A Contribution to Knock Statistics|
|Technical Paper||Improved Control of EGR During Speed/Load Transients|
CitationDiana, S., Giglio, V., Iorio, B., and Police, G., "Evaluation of the Effect of EGR on Engine Knock," SAE Technical Paper 982479, 1998, https://doi.org/10.4271/982479.
- Heywood John B. “Internal Combustion Engine Fundamentals” McGraw-Hill Book Company 1989
- Hickling, R. Chen, F.H.K. Feldmaier, D.A. “Pressure Pulsations in Engine Cylinders” Engine Noise Excitation, vibration and radiation Plenum Press N.Y. 1982
- David, Scholl Davis Craig Russ Stephen Barash Terry “The Volume Acoustic Modes of Spark-Ignited Combustion Chambers” SAE paper 980893 1998
- Xiaofeng Gao Stone Richard Hudson Chris Bradbury Ian “The Detection and Quantification of Knock in Spark Ignition Engines” SAE paper 932759 1993
- Chun, K. M. Heywood, J.B. “Characterization of knock In a SI engine” SAE paper 830509 1983
- Checkel, M.D. Dale, J.D. “Computerized knock detection from engine pressure records SAE paper 860028 1986
- Leppard, W.R. “Individual Cylinder knock occurrence and Intensity in multi-cylinder engines” SAE paper 820074 1982
- Diana, S. Giglio V. Iorio, B. Police G. “A Strategy to improve the Efficiency of Stoichiometric Spark Ignition Engines” SAE paper 961953 1996
- Rabiner Lawrence R. Gold Bernard “Theory and Application of Digital Signal Processing” Prentice-Hall, Inc. Englewood Cliffs, New Jersey 1975
- Ferraro, C.V. Marzano, M. Nuccio, P. “Knock limit measurement in High speed SI engines” SAE paper 850127 1985
- Arrigoni, V. Cornetti, G. Gaetani, B. Ghezzi, P. “Quantitative Systems for Measuring knock” Proc. IME 1972 186
- Brunt, M.F.J. Pond, C.R. Biundo, J. “Gasoline Engine Knock Analysis using Cylinder Pressure Data” SAE paper 980896 1998