NUMERICAL STUDY OF DROPLET VAPORIZATION AND COMBUSTION AT HIGH PRESSURE AND HIGH TEMPERATURE

  • KOO J.-Y. (School of Aerospace and Mechanical Engineering, Hankuk Aviation University) ;
  • KO J.-B. (Graduate School, Hankuk Aviation University)
  • Published : 2005.12.01

Abstract

A numerical study of high pressure and temperature droplet vaporization and combustion is conducted by formulating one dimensional evaporation model and single-step chemical reaction in the mixture of hydrocarbon fuel and air. The ambient pressure ranged from atmospheric conditions to the supercritical conditions. In order to account for the real gas effect on fluid p-v-T properties in high pressure conditions, the modified Soave-Redlich-Kwong state equation is used in the evaluation of thermophysical properties. Some computational results are compared with Sato's experimental data for the validation of calculations in case of vaporization. The comparison between predictions and experiments showed quite a good agreement. Droplet surface temperature increased with increasing pressure. Ignition time increased with increasing initial droplet diameter. Temporal or spatial distribution of mass fraction, mass diffusivity, Lewis number, thermal conductivity, and specific heat were presented.

Keywords

References

  1. Bellan, J. (2000). Supercritical (and Subcritical) fluid behavior and modeling: drops, streams, shear and mixing layers, jets, and spray. Progress in Energy and Combustion Science, 26, 329-366 https://doi.org/10.1016/S0360-1285(00)00008-3
  2. Canada, G. S. and Faeth, G. M. (1973). Fuel droplet burning rates at high pressures. Proc. 14th Symp. (Int.) on Combustion, 135-1354
  3. Curtis, E. W. and Farrel, P. V. (1992). A numerical study of high-pressure droplet vaporization. Combustion and Flame, 90, 85-102 https://doi.org/10.1016/0010-2180(92)90111-2
  4. Delplanque, J. P. and Sirignano, W. A. (1993). Numerical study of the transient vaporization of an oxygen droplet at sub- and super-critical conditions. Int. J Heat and Mass Transfer 36, 2, 303-314 https://doi.org/10.1016/0017-9310(93)80006-G
  5. Graboski, M. S. and Daubert, T. E. (1978). A modified soave equation of state for phase equilibrium calculation, 1. hydrocarbon Systems. Industrial and Engineering Chemistry Process Design and Development 17, 4, 443-448 https://doi.org/10.1021/i260068a009
  6. Hsieh, K. C., Shuen, J. S. and Yang, V. (1991). Droplet vaporization in high-pressure environments I: Near critical conditions. Combustion Science and Technology, 76, 111-132 https://doi.org/10.1080/00102209108951705
  7. Lafon, P. (1995). Modelisation et Simulation Numerique de L'Evaporation et de la Combustion de Gouttes a Haute Pression, Ph.D Dissertation, a L'Universite D'Orleans
  8. Lazar, R. S. and Faeth, G M. (1971). Bipropellant droplet combustion in the vicinity of the critical point. Proc. 13th Symp. (lnt.) on Combustion, 801-811
  9. Lee, M. J., Kim, Y. W., Ha, J. Y. and Chung, S. S. (2001). Effects of watery vapor concentration on droplet evaporation in hot environment. Int. J Automotive Technology 2, 3, 109-115
  10. Manrique, J. A. and Borman, G. L. (1969). Calculations of steady state droplet vaporization at high ambient pressures. Int. J. Heat and Mass Transfer, 12, 1081-1095 https://doi.org/10.1016/0017-9310(69)90117-3
  11. Morin, C., Chauveau, C. and Gokalp, I. (2000). Vaporization of n-alkane droplet at high temperature and pressure. 8th Int. Conf. Liquid Atomization and Spray System, Pasadena, CA, USA
  12. Nomura, H., Ujiie, Y., Rath, H. J., Sato, J. and Kono, M. (1996). Experimental study on high pressure droplet evaporation using microgravity conditions. 26th Symp. (Int.) on Combustion, The Combustion Institute, 1267-1273
  13. Reid, R. C., Prausniz, J. M. and Sherwood, T. K. (1977). Thermal conductivies of gas mixtures at high pressures. The Properties of Gases and Liquids, 10.35-10.38
  14. Sato, J. (1993). Studies on droplet evaporation and combustion in high pressures. AIAA Paper 93-0813
  15. Stephen R. Turns. (1996). An Introduction to Combustion. MacGraw-Hill. Singapore. Int. Edn .. 135-137
  16. Vielle, B., Chauveau, C., Chesnau, X., Odeide, A. and Gokalp, I. (1996). High pressure droplet burning experiments in microgravity, 26th Symp. (Int.) on Combustion, 259-1265
  17. Westbrook, C. K. and Dryer. F. L. (1981). Simplified reaction mechanisms for the oxidation of hydrocarbon fuels in flames. Combustion Science and Technology, 27, 31-43 https://doi.org/10.1080/00102208108946970
  18. Yang, V (2000). Modeling of supercritical vaporization, mixing, and combustion processes in liquid-fueled propulsion system. 28th Symp. (Int.) on Combustion, 925-942
  19. Yang, V., Lin, N. N. and Shuen, J. S. (1994). Vaporization of liquid oxygen (LOX) droplets in supercritical hydrogen environments. Combustion Science and Technology, 97, 247-270 https://doi.org/10.1080/00102209408935380