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A Comprehensive Knock Model for Application in Gas Engines
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 01, 1996 by SAE International in United States
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A predictive knock model that utilizes a phenomenological modeling approach has been developed for predicting the onset of knock in gas engines. Several physical models have been developed and incorporated into WAVE, a comprehensive engine simulation code, including 1) a spatially resolved end gas thermodynamics model; 2) a model for calculating the chemical reaction rates of the reactants in the unburned zone; and 3) a model for approximating the heat transfer between the two-zone combustion model and end gas reaction model.
The established predictive knock model has been demonstrated and validated against experimental data. A WAVE simulation model of the Caterpillar G3508 engine was created and used to predict engine knock over a range of fuels, spark timing and compression ratios. The computational results are compared to test data which were obtained from G3508 detonation timing test. Overall, good correlation was achieved between measured data by Caterpillar and data predicted by WAVE. Finally, a parametric study was performed to evaluate the effects of compression ratio on engine knock performance. Based on the parametric study performed, the knock limited compression ratio can be identified for the G3508 engine under a specified operating condition.
CitationHo, S., Amlee, D., and Johns, R., "A Comprehensive Knock Model for Application in Gas Engines," SAE Technical Paper 961938, 1996, https://doi.org/10.4271/961938.
- WAVE Basic Manual, v.3.3, Ricardo North Amerca, September, 1994.
- WAVE Engine Manual, v.3.3, Ricardo North America, September, 1994.
- WAVE Structural Heat Conduction Manual, v.3.3, Ricardo North America, November, 1994.
- Douaud, A. and Eyzat, P., “Four-Octane-Number Method for Predicting the Anti-Knock Behavior of Fuels and Engines”, SAE#780080.
- Westbrook, C.K., Pitz, W.J. and Leppard, W.R., “The Autoignition Chemistry of Paraffinic Fuels and Pro-Knock and Anti-Knock Additives: A Detailed Chemical Kinnetic Study”, SAE#912314.
- Pitz, W.J., Westbrook, C.K. and Leppard, W.R., “Autoignition Chemistry of C4 Olefins Under Motored Engine Conditions: A comparison of Experimental and Modeling Results”, SAE#912315.
- Pitz, W.J., Westbrook, C.K. and Leppard, W.R., “Autoignition Chemistry of N-Butane in a Motored Engine: A comparison of Experimental and Modeling Results”, SAE#881605.
- Natarajan, B. and Bracco, F.V., “On Multidimensional Modeling of Auto-ignition in Spark-Ignition Engines,” Combustion and Flame, 1984, Vol. 57, pp 179-197.
- Schapertons, H. and Lee, W., “Multidimensional Modeling of knocking Combustion in SI Engines”, SAE#850502.
- Najt, P.M., “Evaluating Threshold Knock with a Semi- Empirical Model-initial Results”, SAE#872149.
- Theobald, M.A. and Cheng, W.K., “A Numerical Study of Diesel Ignition”, Energy Source Technology Conference and Exhibition, Dallas Texas, 1987.
- Kong, S.C. and Reitz, R.D., “Multidimensional Modeling of Diesel Ignition and Combustion Using A Multistep Kinetics Model”, Energy Source Technology Conference and Exhibition, Houston Texas, 1993.
- Westbrook C.K. and Dryer, F.L., “Simplified Reaction Mechanisms for the Oxidation of Hydrocarbons,” Combustion Science and Technology, 1981, Vol. 27, pp. 31-43.
- Bilger, R.W., Starner, S.H. and Kee, R.J., “On Reduced Mechanism for Methane-Air Combustion in Nonpremixed Flames,” Combustion and Flame, 1990, Vol. 80, pp 135-149.
- Karim, G.A. and Gao, J., “Prediction of the Performance of Spark Ignition Gas Engines Including Knock”, SAE#932823.
- Gao, Jing, “A Predictive Model for Knock in Spark Ignition engines Fuelled With Gaseous Fuel”, Ph.D. Thesis, University of Calgary, 1993.