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A Study of In-Cylinder Air Motion in the General Motors VORTEC™ 4.3L, V-6 Engine
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Abstract
The new GM VORTEC gasoline engine has high fuel efficiency and low cyclic variability of combustion- atributes which resulted from fast burn. Organized mixture motion, in the form of swirl, is an element essential for fast burn. The focus of this study is on in-cylinder air motion and its importance to combustion.
Quantifications of in-cylinder air motions resulting from the intake process (swirl) and from piston motion (squish) were made. Swirl was determined experimentally for both straight and helical intake ports. Squish velocities were derived analytically. To determine the relative importance of squish and swirl, the amount of swirl-flow energy dissipated was compared with the amount of squish-flow energy generated. The comparison showed that swirl was the dominant in-cylinder flow.
The impact of swirl on combustion was quantified, and the minimum amount of swirl needed to measurably influence engine operation was determined. These results also explained why helical ports dramatically improved VORTEC engine smoothness and utilization of 91 RON fuels.
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Citation
Pozniak, D. and Rydzewski, J., "A Study of In-Cylinder Air Motion in the General Motors VORTEC™ 4.3L, V-6 Engine," SAE Technical Paper 850510, 1985, https://doi.org/10.4271/850510.Also In
References
- Mattavi, J. H. “The Attributes of Fast Burning Rates in Engines” SAE Paper 800920 1980
- Harada, M. Kadota, T. Sugiyama, Y. “Nissan NAPS-Z Engine Realizes Better Fuel Economy and Low NOx Emission” SAE Paper 810010 1981
- Walker, J. W. Wiltse, R. F. Harhaus, V. W. “The GM 4.3 Liter V-6 Gasoline Engine” SAE Paper 841225 1984
- Tippelmann, G. “A New Method of Investigation of Swirl Ports” SAE Paper 770404 1977
- Asanuma, T. Obokata, T. “Decay of Air Swirl Motion in an Engine Cylinder” Jari Technical Memorandum No. 10 December 1972
- Hirotomi, T. Nagayama, I. Kobayashi, S. “Study of Induction Swirl in a Spark Ignition Engine” SAE Paper 810496 1981
- Hoult, D. P. Wong, V. W. “The Generation of Turbulence in an Internal Combustion Engine” General Motors Research Laboratories Symposium on combustion modeling in reciprocating engines Warren, Michigan November 1978
- Lancaster, D. R. Krieger, R. B. Sorenson, S. C. Hull, W. L. “Effects of Turbulence on Spark-Ignition Engine Combustion” SAE Paper 760160 1976
- Bird, R. B. Stewart, W. F. Lightfoot, E. N. Transport Phenomena John Wiley and Sons New York 156 158
- Lancaster, D. R. “Effects of Turbulence on Spark-Ignition Engine Combustion,” 1975 University of Illinois Ph.D. Thesis Dept. of ME and IE 183