This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
A Comprehensive Knock Model for Application in Gas Engines
Annotation ability available
Sector:
Language:
English
Abstract
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.
Recommended Content
Authors
Citation
Ho, 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.Also In
References
- WAVE Basic Manual Ricardo North Amerca September 1994
- WAVE Engine Manual Ricardo North America September 1994
- WAVE Structural Heat Conduction Manual Ricardo North America November 1994
- Douaud, A. Eyzat, P. “Four-Octane-Number Method for Predicting the Anti-Knock Behavior of Fuels and Engines” SAE# 780080
- Westbrook, C.K. Pitz, W.J. 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. Leppard, W.R. “Autoignition Chemistry of C 4 Olefins Under Motored Engine Conditions: A comparison of Experimental and Modeling Results” SAE# 912315
- Pitz, W.J. Westbrook, C.K. Leppard, W.R. “Autoignition Chemistry of N-Butane in a Motored Engine: A comparison of Experimental and Modeling Results” SAE# 881605
- Natarajan, B. Bracco, F.V. “On Multidimensional Modeling of Auto-ignition in Spark-Ignition Engines,” Combustion and Flame 1984 57 179 197
- Schapertons, H. 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. Cheng, W.K. “A Numerical Study of Diesel Ignition” Energy Source Technology Conference and Exhibition Dallas Texas 1987
- Kong, S.C. 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. Dryer, F.L. “Simplified Reaction Mechanisms for the Oxidation of Hydrocarbons,” Combustion Science and Technology 1981 27 31 43
- Bilger, R.W. Starner, S.H. Kee, R.J. “On Reduced Mechanism for Methane-Air Combustion in Nonpremixed Flames,” Combustion and Flame 1990 80 135 149
- Karim, G.A. 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” University of Calgary 1993