COMBUSTION CHARACTERISTICS OF HOMOGENEOUS CHARGED METHANE-AIR MIXTURE IN A CONSTANT VOLUME COMBUSTION CHAMBER

  • CHOI S. H. (Department of Mechanical Engineering, RIMT, Pusan National University) ;
  • CHO S. W. (Department of Mechanical Engineering, RIMT, Pusan National University) ;
  • JEONG D. S. (Engine Lab., Korea Institute of Machinary and Materials) ;
  • JEON C. H. (Department of Mechanical Engineering, RIMT, Pusan National University) ;
  • CHANG Y. J. (Department of Mechanical Engineering, RIMT, Pusan National University)
  • Published : 2005.06.01

Abstract

A cylindrical constant volume combustion chamber was used to investigate the flow characteristics at the spark electrode gap and the combustion characteristics of a homogeneous charged methane-air mixture under various overall charge pressures, excess air ratios and ignition times. The flow characteristics, including the mean velocity and turbulence intensity, were analyzed with a hot wire anemometer. Combustion pressure development measured by piezoelectric pressure transducer, a flame propagation image acquired by ICCD camera and exhaust emissions measured by 2-valve gas chromatography were used to investigate effects of initial pressures, excess air ratios and ignition times on the combustion characteristics. It was found that the mean velocity and turbulence intensity had the maximum value around 200-300 ms and then decreased gradually to a near-zero value after 3000 ms and that the combustion duration was shorten and the flame speed and laminar burning velocity had the highest value under the condition of an excess air ratio of 1.1, an overall charge pressure of 0.15 MPa and an ignition time of 300 ms in the present study. The $CO_2$ concentration was proportional to the ignition time and overall charge pressure, the $CO_2$ concentration was proportional to the excess air ratio, and the UHC concentration was inversely proportional to the ignition time and overall charge pressure.

Keywords

References

  1. Choi, S. H., Jeon, C. H. and Chang, Y. J. (2003). Combustion characteristics of methane-air mixture in a constant volume combustion chamber (2): Inhomogeneous charge. Trans. Korean Society of Automotive Engineers 11, 4, 29-36
  2. Choi, S. H., Jeon, C. H. and Chang, Y. J. (2004). Combustion characteristics of inhomogeneous methane-air mixture in a constant volume combustion chamber. Int. J. Automotive Technology 5, 3, 181-188
  3. Frank, R. M. and Heywood, J. B. (1991). The effect of piston temperature on hydrocarbon emissions from a spark-ignited direct-injection engine. SAE Paper No. 910558
  4. Furuno, S., Iguchi, S. and Inoue, T. (1995). Lean combustion characteristics of locally stratified charge mixture: Basic studies of in-vessel combustion ignited by laser. JSAE Review, 16, 357-361 https://doi.org/10.1016/0389-4304(95)00034-5
  5. Hjima, T. and Takeno, T. (1986). Effects of temperature and pressure on burning velocity. Combustion and Flame, 65, 35-43 https://doi.org/10.1016/0010-2180(86)90070-2
  6. Kato, K., Saeki, K., Nishide, H. and Yamada, T. (2001). Development ofCNG fueled engine with lean bum for small size commercial van. JSAE Review, 22, 365-368 https://doi.org/10.1016/S0389-4304(01)00104-7
  7. Kim, T. K., Kim, S. H. and Jang, J. Y. (2000). CO, $CO_2$ and NOx emission characteristics of methane-air premixed flame in constant volume combustion chamber. Trans. Korean Society of Automotive Engineers 8, 5, 19-26
  8. Lee, C. S., Kim, D. S. and Oh, K. S. (1996). A study on the combustion characteristics of methane-air mixture in constant volume combustion chamber. Trans. Korean Society of Automotive Engineers 4, 4, 201-209
  9. Lefebvre, A. H. (1999). Gas Trubine Combustion. Taylor and Francis. Philadelphia. USA
  10. Lewis, B. and von Elbe, G. (1987). Combustion, Flames and Explosions of Gases. Academic Press. New York. USA
  11. Maji, S., Ranjan, R. and Sharma, P. B. (2000). Comparison of emissions and fuel consumption from CNG and gasoline fueled vehicles - effect of ignition timing. SAE Paper No. 2000-01-1432
  12. Najm, H. N., Paul, P. H., Mueller, C. J. and Wyckoff, P. S. (1998). On the adequacy of certain experimental observables as measurements of flame burning rate. Combustion and Flame, 113,312-332 https://doi.org/10.1016/S0010-2180(97)00209-5
  13. Ryan, T. W. and Lestz, S. S. (1980). The laminar burning velocity of isooctane, n-heptane, methanol, methane, and propane at elevated temperature and pressures in the presence of a diluent. SAE Paper No. 800103
  14. Strauss, W. A. and Edse, R. (1959). Burngine velocity measurements by the constant-pressure bomb method. Seventh Symposium (International) on Combustion London, UK. 377-385
  15. Strehlow, R. A. (1984). Combustion Fundamentals, McGraw-Hill. New York. USA
  16. Ursu, B. and Perry, G.. C. (1996). Natural gas powered heavy duty truck demonstration. SAE Paper No. 961669