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Effect of Engine and Fuel Variables on Liquid Fuel Transport into the Cylinder in Port-Injected SI Engines
Technical Paper
1999-01-0563
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Liquid fuel inflow into the cylinder is considered to be an important source of exhaust hydrocarbon (HC) emissions from automotive spark ignition engines. These liquid-fuel-caused emissions are increased significantly during the start up and subsequent warm-up period. This study analyzes the influence of several engine and injector design variables, and fuel parameters, on the in-cylinder liquid fuel behavior. The effect of the following parameters on the characteristics of the fuel droplets entering the cylinder was studied: Fuel volatility, injection timing, intake valve timing, injector type, spray geometry, and spray targeting in the intake port.
A Phase Doppler Particle Analyzer (PDPA) was used in a single-cylinder flow visualization combustion engine to assess this in-cylinder liquid fuel behavior. Measurements of fuel droplet characteristics (size and velocity) were taken in selected locations in the vicinity of the intake valve during starting and warm up. The measurements were performed with open and closed valve injection timing for each of the parameters listed above.
A previous paper by the authors [1] identified four different mechanisms that carry liquid fuel droplets into the cylinder (first forward flow atomization, high speed intake air transport, injection contribution, and fuel film squeezing). The present study shows substantial dependence of in-cylinder liquid fuel characteristics on the above parameters, both during starting and under warmed up conditions. It is shown that the droplet size distribution, the amount of liquid fuel, and the spatial distribution of droplet characteristics around the intake valve circumference were affected to different degrees. The observed trends in the droplet characteristics are explained in terms of changes in the previously identified mechanisms. The observed differences in in-cylinder liquid fuel behavior are significant enough to be reflected in engine out emissions behavior.
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Meyer, R. and Heywood, J., "Effect of Engine and Fuel Variables on Liquid Fuel Transport into the Cylinder in Port-Injected SI Engines," SAE Technical Paper 1999-01-0563, 1999, https://doi.org/10.4271/1999-01-0563.Also In
References
- Meyer R. Yilmaz E. Heywood, J.B. “Liquid Fuel Flow in the Vicinity of the Intake Valve in a Port Injected SI Engine” SAE Paper 982471 1998
- Fischer, H.C. Brereton, G.J “Fuel Injection Strategies to Minimize Cold-Start HC Emissions” SAE Paper 970040 1997
- Yang, J. Kaiser, E.W. Siegl, W.O. Anderson, R.W. “Effects of Port-Injection Timing and Fuel Droplet Size on Total and Speciated Exhaust Hydrocarbon Emissions” SAE Paper 930711 1993
- Kaiser, E.W. Siegl, W.O. Lawson, G.P. Connolly, F.T. Cramer, C.F. Dobbins, K.L. Roth, P.W. Smokovitz, M. “Effect of Fuel Preparation on Cold-Start Hydrocarbon Emissions from a Spark-Ignited Engine” SAE Paper 961957 1996
- Shayler, P.J. Davies, M.T. Colechin, M.J.F. Scarisbrick, A. “Intake Port Fuel Transport and Emissions: The Influence of Injector Type and Fuel Composition” SAE Paper 961996 1996
- Zhao, F. Yoo, J. Lai, M. “Spray Targeting Inside a Production-type Intake Port of a 4-Valve Gasoline Engine” SAE Paper 960115 1996 SAE Transactions 105 1996
- Meyer R. Heywood, J.B. “Liquid Fuel Transport into the cylinder of a Firing Port-Injected SI Engine During Start Up” SAE Paper 970865 1997 SAE Transactions 107 1997
- Fraser, R.P. Dombrowski, N. Routly, J.H. “The atomization of a Liquid Sheet by an Impinging Air Stream” Chemical Engineering Science 1963 18 339 353 pergamon Press Ltd. Oxford, UK
- Curtis, E.W. Aquino, C.F. Trumpy, D.K. Davis, G.C. “A New Port and Cylinder Wall Wetting Model to Predict Transient Air/Fuel Excursions in a Port Fuel Injected Engine” SAE Paper 961186 1996
- O'Rourke, P.J. Amsden, A.A. “A Particle Numerical Model for Wall Film Dynamics in Port-Injected Engines” SAE Paper 961961 1996
- Simmons, H.C. ‘The Prediction of Sauter Mean Diameter for Gas Turbine Fuel Nozzles of Different Types” ASME Transactions 102 July 1980 646 652
- Rizk, N.K. Lefebvre, A.H. “The Influence of Liquid Film Thickness on Airblast Atomization” ASME Transactions 102 July 1980 706 710
- Harrrington, D. 1997