Determination of Diesel Sprays Characteristics in Real Engine In-Cylinder air Density and Pressure Conditions

  • Payri Raul (CMT - Motores Termicos, Universidad Politecnica de Valencia) ;
  • Salvador F. J. (CMT - Motores Termicos, Universidad Politecnica de Valencia) ;
  • Gimeno J (CMT - Motores Termicos, Universidad Politecnica de Valencia) ;
  • Soare V. (CMT - Motores Termicos, Universidad Politecnica de Valencia)
  • Published : 2005.11.01

Abstract

The present paper centers on the establishment of a quantified relationship between the macroscopic visual parameters of a Diesel spray and its most influential factors. The factors considered are the ambient gas density, as an external condition relative to the injection system, and nozzle hole diameter and injection pressure as internal ones. The main purpose of this work is to validate and extend the different correlations available in the literature to the present state of the Diesel engine, i.e. high injection pressure, small nozzle holes, severe cavitating conditions, etc. Five mono-orifice, axi-symmetrical nozzles with different diameters have been studied in two different test rigs from which one can reproduce solely the real engine in-cylinder air density, and the other, both the density and the pressure. A parametric study was carried out and it enabled the spray tip penetration to be expressed as a function of nozzle hole diameter, injection pressure and environment gas density. The temporal synchronization of the penetration and injection rate data revealed a possible explanation for the discontinuity observed as well by other authors in the spray's penetration law. The experimental results obtained from both test rigs have shown good agreement with the theoretical analysis. There have been observed small but consistent differences between the two test rigs regarding the spray penetration and cone angle, and thus an analysis of the possible causes for these differences has also been included.

Keywords

References

  1. Arai, M., Shimizu, M. and Hiroyasu, H., 1991, 'Similarity between the Break-up Lengths of a High Speed Liquid Jet in Atmospheric and Pressurized Conditions,' In ICLASS-91, Gaithersburg, Maryland
  2. Arregle, J., Pastor, J. V. and Ruiz, S., 1999, 'The Influence of Injection Parameters on Diesel Spray Characteristics,' SAE Paper 1999-01-0200
  3. Bosch, W., 1966, 'The Fuel Rate Indicator: A New Measuring Instrument for Display of the Characteristics of Individual Injection,' SAE Paper 660749
  4. Cheong, S. -K., Liu, J., Shu, D., Wang, J. and Powell, C. F., 2004, 'Effects of Ambient Pressure on Dynamics of Near- Nozzle Diesel Sprays Studied by Ultrafast X-Radiography,' SAE Paper 2004-01-2026
  5. Dent, J. C., 1971, 'A Basis for the Comparison of Various Experimental Methods for Studying Spray Penetration,' SAE Paper 710571
  6. Desantes, J. M., Payri, R, Salvador, F. J. abd Gimeno, J., 2003, 'Measurements of Spray Momentum for the Study of Cavitation in Diesel Injection Nozzles,' SAE Paper 2003-01-0703
  7. Desantes, J. M., Payri, R., Pastor, J. M. and Gimeno, J., 2005, 'Experimental Analysis of Fuel Evaporation in Diesel Sprays. Part I. Nozzle characterization,' Atomization and Sprays, Vol. 15, pp. 489-516 https://doi.org/10.1615/AtomizSpr.v15.i5.20
  8. Hay, N. and Jones, P. L., 1972, 'Comparison of the Various Correlations for Spray Penetration,' SAE Paper 720776
  9. Hiroyasu, H. and Arai, M., 1990, 'Structures of Fuel Sprays in Diesel Engines,' SAE Paper 900475
  10. Hurly, J. J., Defibaugh, D. R. and Moldover, M. R., 2000, 'Thermodynamic Properties of $SF_6$,' Int. J. Thermophysics 2000, 21, pp. 739-765 https://doi.org/10.1023/A:1006697620523
  11. Kim, C. H. and Lee, J. S., 2003, 'An Analytical Study on the Performance Analysis of a Unit-Injector System of a Diesel Engine,' KSME International Journal, Vol. 17, No.1, pp. 146-156
  12. Koo, J. Y., 2003, 'The Effects of Injector Nozzle Geometry and Operating Pressure Conditions on the Transient Fuel Spray Behavior,' KSME International Journal, Vol. 17, No. 3, pp. 617-625
  13. Macian, V., Payri, R., Margot, X. and Salvador, F. J., 2003a, 'A CFD Analysis of the Influence of Diesel Nozzle Geometry on the inception of Cavitation,' Atom Sprays 2003, 13, pp. 579-604 https://doi.org/10.1615/AtomizSpr.v13.i56.80
  14. Macian, V., Bermudez, V., Payri, R. and Gimeno, J., 2003b, 'New Technique for the Determination of the Internal Geometry of Diesel Nozzle with the use of the Silicone Methodology,' Exp. Tech 2003, 27 (2), pp. 39-43 https://doi.org/10.1111/j.1747-1567.2003.tb00107.x
  15. MacPhee, A. G., Tate, M. W., Powell, C. F., Yue, Y., Renzi, M. J. et al., 2002, 'X-ray Imaging of Shock Waves Generated by High-pressure Fuel Sprays,' Science, Vol. 295, pp. 1261-1263 https://doi.org/10.1126/science.1068149
  16. Naber, J. and Siebers, D.L., 1996, 'Effects of gas density and vaporisation on penetration and dispersion of Diesel sprays,' SAE Paper 960034
  17. Pastor, J. V, Payri, R., Lopez, J. J. and Julia, J. E., 2003, 'Effect of Injector Nozzle Geometry of Diesel Engines on the Macroscopic Spray Characteristics by Means of Optical Techniques,' Fuel Injection Systems. ImechE Conference Transactions. C610/014/2003, pp. 73-82
  18. Pastor, J. V., Arregle, J. and Palomares, A., 2001, 'Diesel Spray Image Segmentation with a Likelihood Ratio Test,' Applied Optics, Vol. 40, No. 17, pp. 2876-2885 https://doi.org/10.1364/AO.40.002876
  19. Payri, F., Desantes, J. M. and Arregle, J., 1996, 'Characterization of D.l. Diesel Sprays in High Density Conditions,' SAE Paper 960774
  20. Payri, F., Bermudez, V., Payri, R. and Salvador, F. J., 2004, 'The Influence of Cavitation on the Internal Flow and the Spray Characteristics in Diesel Injection Nozzles,' Fuel 2004, 83, 419-31 https://doi.org/10.1016/j.fuel.2003.09.010
  21. Payri, R., Margot, X. and Salvador, F. J., 2002, 'A Numerical Study of the Influence of Diesel Nozzle Geometry on the Inner Cavitating Flow,' SAE Paper 2002-01-215
  22. Payri, R., Molina, S., Salvador, F. J. and Gimeno, J., 2004a, 'A Study of the Relation between Nozzle Geometry, Internal Flow and Sprays Characteristics in Diesel Fuel Injection Systems,' KSME International Journal, Vol. 18, No.7, pp. 1222-1235
  23. Payri, R., Guardiola, C., Salvador, F. J. and Gimeno, J., 2004b, 'Critical Cavitation Number Determination in Diesel Injection Nozzles,' Experimental Techniques, Vol. 28, No. 3, pp. 49-51 https://doi.org/10.1111/j.1747-1567.2004.tb00164.x
  24. Payri, R., Climent, H., Salvador, F.J., Favennec, A. G., 2004c, 'Diesel Injection System Modelling. Methodology and Application for a First-generation Common Rail System,' Proc. Instn. Mech. Engrs., Vol. 218, Part D : Automobile Engineering, pp. 81-91 https://doi.org/10.1243/095440704322829191
  25. Payri, R., Garcia, J.M., Salvador, F.J., Gimeno, J., 2005, 'Using Spray Momentum Flux Measurements to Understand the Influence of Diesel Nozzle Geometry on Spray Characteristics,' Fuel 2005, 84, pp. 551-561 https://doi.org/10.1016/j.fuel.2004.10.009
  26. Wakuri, Y., Fujii, M., Amitani, T. and Tsuneya, R., 1960, 'Studies of the Penetration of a Fuel Spray in a Diesel Engine,' Bull. J.S.M.E., 3(9), pp. 123-130 https://doi.org/10.1299/jsme1958.3.123