This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
The Effect of Spark Retard on Engine-out Hydrocarbon Emissions
Technical Paper
2005-01-3867
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Using spark retard during a cold-start is a very effective means of achieving fast catalyst light-off. In addition to obtaining faster catalyst light-off, retarding the spark also results in lower engine-out HC emissions. The objective of this research was to understand the reasons for the decrease in HC emissions with spark retard. In order to make the results as unambiguous as possible, the experiments were performed on a dynamometer at constant speed and load conditions using pre-vaporized, premixed gasoline. A zero-dimensional ring-pack crevice flow model was used to determine the mass flows into and out of the piston crevice during the engine cycle. The analysis showed that with spark retard a large fraction of the unburned fuel from the ring-pack re-entered the cylinder before the end of flame propagation, and was consumed by the flame when it extinguished on the cylinder wall. The level of post-flame HC consumption was estimated as the difference between the measured engine-out HC emissions and the unburned fuel re-entering the cylinder after the end of flame propagation, which was taken to be the crankangle of 90% mass fraction burned. Even with the most severe levels of spark retard the majority of the HC consumption, up to 70%, takes place by the flame within the cylinder before exhaust valve opening.
Recommended Content
Authors
Citation
Eng, J., "The Effect of Spark Retard on Engine-out Hydrocarbon Emissions," SAE Technical Paper 2005-01-3867, 2005, https://doi.org/10.4271/2005-01-3867.Also In
References
- Advanced Developments in Ulta-Clean Gasoline-Powered Vehicles Zhao, F. SAE Technical Publication PT-104 2004
- Russ, S. Thiel, M. Lavoie, G. SI Engine Operation with Retarded Ignition: Part 2- HC Emissions and Oxidation SAE Technical Paper, No. 1999-01-3507 1999
- Westbrook, C. K. Adamczyk, A. A. Lavoie, G. A. A Numerical Study of Laminar Flame Wall Quenching, Comb. and Flame 40 81 99 1981
- Kaiser, E. W. et al. Fuel Composition Effects on Hydrocarbon Emissions From A Spark-Ignition Engine - Is Fuel Absorption in Oil Significant? SAE Technical Paper, No. 952542 1995
- Cheng, W. K. et al. An Overview of Hydrocarbon Emissions Mechanisms in Spark-Ignition Engines SAE Technical Paper, No. 932708 1993
- Eng, J. A. Leppard, W. R. Najt, P. M. Dryer, F. L. Experimental Hydrocarbon Consumption Rate Correlations From a Spark Ignition Engine SAE Technical Paper, No. 972888 1997
- Alkidas, A. C. Combustion Chamber Crevices: The Major Source of Engine-Out Hydrocarbon Emissions Under Fully Warmed Conditions Prog In Energy and Comb Sci 25 1999
- Olivera, I. B. et al. Effect of Operating Conditions and Fuel Type on Crevice HC Emissions: Model Results and Comparison With Experiments SAE Technical Paper, No. 1999-01-3578 1999
- Eng, J. A. Leppard, W. R. Najt, P. M. Dryer, F. L. The Effect of Fuel Composition on Hydrocarbon Emissions From a Spark-Ignition Engine: Iso-Octane/Toluene and n-Octane/Toluene Fuel Mixtures SAE Technical Paper, No. 982557 1998
- Tamura, M. et al. A Study of Crevice Flow in a Gas Engine Using Laser-Induced Fluorescence SAE Technical Paper, No. 2001-01-0913 2001
- Bian, X. et al. Tracer Fuel Injection Studies on Exhaust Port Hydrocarbon Oxidation SAE Technical Paper, No. 982559 1998
- Yang, W. et al. Tracer Fuel Injection Studies on Exhaust Port Hydrocarbon Oxidation: Part II SAE Technical Paper, No. 2000-01-1945 2000
- Namazian, M. Heywood, J. B. Flow in the Piston-Cylinder-Ring Crevices of a Spark Ignition Engine: Effect on Hydrocarbon Emissions, Efficiency and Power SAE Technical Paper, No. 820088 1982
- Yun, H. J. Mirsky, W. Schlieren-Streak Measurements of Instantaneous Exhaust Gas Velocities from a Spark-Ignition Engine SAE Technical Paper, No. 741015 1974
- Borland, M. Zhao, F. Application of Secondary Air Injection for Simultaneously Reducing Converter-In Emissions and Improving Catalyst Light-Off Performance SAE Technical Paper, No. 2002-01-2803 2002