EXPERIMENTAL STUDY ON THE FLOW AND MIXTURE DISTIBUTION IN A VISUALIZATION ENGINE USING DIGITAL PARTICLE IMAGE VELOCIMETRY AND ENTROPY ANALYSIS

  • Lee, K.H. (Department of Mechanical Engineering, Hanyang University) ;
  • Lee, C.H. (Department of Mechanical Engineering, Hanyang University)
  • Published : 2007.04.30

Abstract

The objective of this study is to analyze the effect of velocity and vorticity on stratified mixture formation in the visualization engine. In order to investigate spray behavior, the pray velocity is obtained through the cross-correlation PIV method, a useful optical diagnostics technology and the vorticity calculated from the spray velocity component. These results elucidated the relationship between vorticity and entropy, which play an important role in the diffusion process for the early injection case and the stratification process for the late injection case. In addition, we quantified the homogeneous diffusion ate of spray using entropy analysis based on Boltzmann's statistical thermodynamics. Using these methods, we discovered that the homogeneous mixture distribution is more effective as a momentum dissipation of surrounding air than that of the spray concentration with a change in the injection timing. We found that the homogenous diffusion rate increased as the injection timing moved to the early intake stroke process, and BTDC $60^{\circ}$ was the most efficient injection timing for the stratified mixture formation during the compression stroke.

Keywords

References

  1. Chapra, S. C. (1998). Numerical Methods for Engineers. McGraw-Hill Inc.. New York. 529
  2. Iwakiri, Y. and Kakuho, A. (1999). Effectiveness and issues of various measurement techniques used in evaluating spray characteristics in a direct-injection gasoline engine. Pro. 15th Int. Com. Engine Symp. 9935095
  3. Kume, T., Iwamoto, Y., Iida, K., Murakami, M. Akishino, K. and Ando, H. (1996). Combustion controlled technologies for direct injection SI engine. SAE Paper No. 960600
  4. Luff, J. D. (1999). Experimental uncertainties associated with particle image velocimetry based vorticity algorithms. Exp. Fluids, 26, 36-54 https://doi.org/10.1007/s003480050263
  5. Michael, H. and Brad, A. (1998). Early spray development in gasoline direct-injected spark ignition engine. SAE Paper No. 980160
  6. Preussner, C. and Doring Fehier, S. and Kampmann, S. (1998). GDI: Interaction between mixture preparation, combustion system and injector performance. SAE Paper No. 980498
  7. Ruan, X. and Song, X. (2001). Direct measurement of the vorticity field in digital particle images. Exp. Fluids, 30, 696-704 https://doi.org/10.1007/s003480000249
  8. Takagi, Y. and Teruyuki, T. (1998). Simultaneous attainment of low fuel consumption, high output power and low exhaust emissions in direct injection SI engine. SAE Paper No. 980149
  9. Toshio, S. and Koichiro, T. (2001). Analysis of direct injection SI stratified combustion in hydrogen lean mixture–combustion promotion and cooling loss. Int. J. Automotive Technology 2, 3, 85-91
  10. Yamakawa, M., Isshiki, S., Yoshizaki, T. and Nishida, K. (2001). Measurement of ambient air motion of D.I. gasoline spray by LIF-PIV. COMODIA 2001, 499-504
  11. Yuyama, R., Chikahisa, T., Kikuta, K. and Hishinuma, (2001). Entropy analysis of microscopic diffusion phenomena in diesel sprays. COMODIA 2001, 542-550
  12. Zhao, F. Q. and Lai, M. C. (1997). A review of mixture preparation and combustion control strategies for sparkignited direct-Injection gasoline engine. SAE Paper No. 970627
  13. Zhao, F.-Q., Yoo, J.-H. and Lai, M.-C. (1996). Spray dynamics of high pressure fuel injectors for DI gasoline engines. SAE Paper No. 961925