Journal of Mechanical Science and Technology

  • 제17권6호
  • /
  • Pages.888-895
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  • 2003
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  • 1738-494X(pISSN)
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  • 1976-3824(eISSN)
대한기계학회 (The Korean Society of Mechanical Engineers)
권호 표지

Piston Crevice Hydrocarbon Oxidation During Expansion Process in an SI Engine

  • Kyoungdoug Min (School of Mechanical and Aerospace Engineering, Seoul National University) ;
  • Kim, Sejun (School of Mechanical and Aerospace Engineering, Seoul National University)
  • 발행 : 2003.06.01
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초록

Combustion chamber crevices in SI engines are identified as the largest contributors to the engine-out hydrocarbon emissions. The largest crevice is the piston ring-pack crevice. A numerical simulation method was developed, which would allow to predict and understand the oxidation process of piston crevice hydrocarbons. A computational mesh with a moving grid to represent the piston motion was built and a 4-step oxidation model involving seven species was used. The sixteen coefficients in the rate expressions of 4-step oxidation model are optimized based on the results from a study on the detailed chemical kinetic mechanism of oxidation in the engine combustion chamber. Propane was used as the fuel in order to eliminate oil layer absorption and the liquid fuel effect. Initial conditions of the burned gas temperature and in-cylinder pressure were obtained from the 2-zone cycle simulation model. And the simulation was carried out from the end of combustion to the exhaust valve opening for various engine speeds, loads, equivalence ratios and crevice volumes. The total hydrocarbon (THC) oxidation in the crevice during the expansion stroke was 54.9% at 1500 rpm and 0.4 bar (warmed-up condition). The oxidation rate increased at high loads, high swirl ratios, and near stoichiometric conditions. As the crevice volume increased, the amount of unburned HC left at EVO (Exhaust Valve Opening) increased slightly.

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참고문헌

  1. Cheng, W. K., Hamrin, D., Heywood, J. B., Hochgreb, S., Min, K. and Norris, M., 1993, 'An Overview of Hydrocarbon Emissions Mechanisms in Spark-Ignition Engines,' The Society of Automotive Engineers, SAE parper No. 932708
  2. Dagaut, P., Cathonnet. M., Boettner, J. C. and Gaillard, F., 1987, 'Kinetic Modeling of Propane Oxidation,' Combustion Science and Technology, Vol. 56, pp. 23-63 https://doi.org/10.1080/00102208708947080
  3. Hautman, D. J., Dryer, F. L., Schug, K. P. and Glassman, I., 1981, 'A Multiple-step Overall Kinetic Mechanism for the Oxidation of Hydrocarbons,' Combustion Science and Technology, Vol. 25, pp. 219-235 https://doi.org/10.1080/00102208108547504
  4. Kee, R. J., Rupley, F. M. and Miller, J. A., 1989, 'Chemkin-Ⅱ: A Fotran Chemical Kinetics Package for the Analysis of Gas-Phas Chemical Kinetics,' SAND 89-80009
  5. Kim. S. J., 2000, 'Numerical Simulation of Post Flame Oxidation of Hydrocarbons from Piston Crevice of SI Engines,' M.S. thesis of Seoul National Univ.
  6. Launder, B. E. and Spalding, D. B., 1972, 'Mathematical Models of Turbulence,' Academic Press
  7. Min, K., 1994, 'The Effects of Crevices on the Engine-Out Hydrocarbon Emissions in Spark Ignition Engines,' Ph.D. Thesis, Department of Mechanical Engineering, MIT
  8. Poulos, S. G., 1982, 'The Effect of Combustion Chamber Geometry on S.I. Engine Combustion Rates-A modeling Study,' M.S. thesis of MIT
  9. Son, S. G., Yun, S. W., Kim, D. J., Lee, K. Y. and Choi, B. C., 2000, 'A Study of HC Reduction with Hydrocarbon Absorber Systems,' KSME International Journal 14, 10
  10. Wahiduzzaman, S. and Ferguson, C. R., 1986, 'Convective Heat Transfer from Decaying Swirling Flow within a Cylinder,' 8th International Heat Transfer Conference, paper #86-IHTC-253, August
  11. William, H. P., Saul A. T., William, T. V. and Brian P. F., 1992, 'Numerical Recipes in C Second Edition,' Press Syndicate of the University of Cambridge, pp. 412-420