International Scientific Journal


Molecular dynamics simulation is performed to study the influence of environmental pressure on the mixing process. Based on the OPLS-AA full-atomic potential function, the gas-liquid-gas simulation box model is used to study the evaporation characteristics of n-heptane at different environmental conditions. The results show that compared with the subcritical environment, the nitrogen molecules in the supercritical condition can diffuse into the liquid phase region earlier, and the temperature of the liquid phase rise faster, and then a unified supercritical fluid could be formed. Based on the density profile, a gas-liquid-gas interface thickness is defined and the interface thickness is widened as the ambient pressure increase, resulting in the conventional subcritical evaporation transition turbulent mixing process.
PAPER REVISED: 2021-09-18
PAPER ACCEPTED: 2021-09-30
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THERMAL SCIENCE YEAR 2022, VOLUME 26, ISSUE Issue 4, PAGES [3517 - 3527]
  1. Y. Ahn, S. J. Bae, M. Kim, S. K. Cho, S. Baik, J. I. Lee, et al., "Review of supercritical CO 2 power cycle technology and current status of research and development," Nuclear Engineering & Technology, vol. 47, pp. 647-661, 2015.
  2. Ž. Knez, E. Markočič, M. Leitgeb, M. Primožič, M. K. Hrnčič, and M. Škerget, "Industrial applications of supercritical fluids: A review," Energy, vol. 77, pp. 235-243, 2014.
  3. V. Yang, "Modeling of supercritical vaporization, mixing, and combustion processes in liquid-fueled propulsion systems," Proceedings of the Combustion Institute, vol. 28, pp. 925-942, 2000.
  4. J. Bellan, "Supercritical (and subcritical) fluid behavior and modeling: drops, streams, shear and mixing layers, jets and sprays," Progress in Energy & Combustion Science, vol. 26, pp. 329-366, 2000.
  5. M. Oschwald and A. Schik, "Supercritical nitrogen free jet investigated by spontaneous Raman scattering," Experiments in Fluids, vol. 27, pp. 497-506, 1999.
  6. B. Chehroudi, R. Cohn, and D. Talley, "Cryogenic shear layers: experiments and phenomenological modeling of the initial growth rate under subcritical and supercritical conditions," International Journal of Heat & Fluid Flow, vol. 23, pp. 554-563, 2002.
  7. B. Chehroudi, D. Talley, and E. Coy, "Visual characteristics and initial growth rates of round cryogenic jets at subcritical and supercritical pressures," Physics of Fluids, vol. 14, pp. 850-861, 2002.
  8. R. Branam and W. Mayer, "Characterization of Cryogenic Injection at Supercritical Pressure," Journal of Propulsion & Power, vol. 19, pp. 342-355, 2003.
  9. W. Mayer, J. Telaar, R. Branam, G. Schneider, and J. Hussong, "Raman Measurements of Cryogenic Injection at Supercritical Pressure," Heat & Mass Transfer, vol. 39, pp. 709-719, 2003.
  10. C. Segal and S. A. Polikhov, "Subcritical to supercritical mixing," Physics of Fluids, vol. 20, p. 4, 2008.
  11. J. Oefelin, "Analysis of transcritical spray phenomena in turbulent mixing layers," in 34th Aerospace Sciences Meeting and Exhibit, 1996.
  12. J. C. Oefelein and V. Yang, "Modeling High-Pressure Mixing and Combustion Processes in Liquid Rocket Engines," Journal of Propulsion & Power, vol. 14, pp. 843-857, 1998.
  13. G. S. Zhu and S. K. Aggarwal, "Transient supercritical droplet evaporation with emphasis on the effects of equation of state," International Journal of Heat & Mass Transfer, vol. 43, pp. 1157-1171, 2000.
  14. G. S. Zhu, R. D. Reitz, and S. K. Aggarwal, "Gas-phase unsteadiness and its influence on droplet vaporization in sub- and super-critical environments," International Journal of Heat & Mass Transfer, vol. 44, pp. 3081-3093, 2001.
  15. H. Meng and V. Yang, "Clustering effects on liquid oxygen (LOX) droplet vaporization in hydrogen environments at subcritical and supercritical pressures," International Journal of Hydrogen Energy, vol. 37, pp. 11815-11823, 2012.
  16. H. Meng and V. Yang, "Vaporization of two liquid oxygen (LOX) droplets in tandem in convective hydrogen streams at supercritical pressures," International Journal of Heat & Mass Transfer, vol. 68, pp. 500-508, 2014.
  17. K. C. Hsieh, J. S. Shuen, and V. Yang, "Droplet Vaporization In High-Pressure Environments I: Near Critical Conditions," Combustion Science & Technology, vol. 76, pp. 111-132, 1991.
  18. R. D. Branam, Molecular dynamics simulation of supercritical fluids, 2005.
  19. M. Moseler and U. Landman, "Formation, Stability, and Breakup of Nanojets," Science, vol. 289, p. 1165, 2000.
  20. M. M. Micci, T. L. Kaltz, and L. N. Long, "Molecular dynamics simulations of atomization and spray phenomena," Atomization & Sprays, vol. 11, pp. 351-363, 2001.
  21. H. H. Shin and W. S. Yoon, "Non-equilibrium molecular dynamics simulation of nanojet injection with adaptive-spatial decomposition parallel algorithm," Journal of Nanoscience & Nanotechnology, vol. 8, p. 3661, 2008.
  22. H. H. Shin, D. Suh, and W. S. Yoon, "Non-equilibrium molecular dynamics of nanojet injection in a high pressure environment," Microfluidics & Nanofluidics, vol. 5, pp. 561-570, 2008.
  23. T. H. Fang, W. J. Chang, and S. C. Liao, "Effects of temperature and aperture size on nanojet ejection process by molecular dynamics simulation," Microelectronics Journal, vol. 35, pp. 687-691, 2004.
  24. Y. S. Choi, S. J. Kim, and M. U. Kim, "Molecular dynamics of unstable motions and capillary instability in liquid nanojets," Phys Rev E Stat Nonlin Soft Matter Phys, vol. 73, p. 016309, 2006.
  25. W. Wei, H. Liu, L. Deng, M. Jia, and M. Xie, "Non-equilibrium molecular dynamics modeling of a fuel nanojet in sub/supercritical environments: chamber pressure effects on characteristics of the gas-liquid interface," Nanoscale & Microscale Thermophysical Engineering, vol. 22, 2017.
  26. S. Sumardiono and J. Fischer, "Molecular simulations of droplet evaporation by heat transfer," Microfluidics & Nanofluidics, vol. 3, pp. 127-140, 2007.
  27. J. F. Xie, S. S. Sazhin, and B. Y. Cao, "Molecular Dynamics Study of Condensation/Evaporation and Velocity Distribution of N-Dodecane at Liquid-Vapour Phase Equilibria," Journal of Thermal Science & Technology, vol. 7, pp. 288-300, 2012.
  28. G. Mo and L. Qiao, "A molecular dynamics investigation of n-alkanes vaporizing into nitrogen: transition from subcritical to supercritical," Combustion & Flame, vol. 176, pp. 60-71, 2017.
  29. E. S. Landry, S. Mikkilineni, M. Paharia, and A. J. H. Mcgaughey, "Droplet evaporation: A molecular dynamics investigation," Journal of Applied Physics, vol. 102, p. 191, 2007.
  30. J. H. Walther and P. Koumoutsakos, "Molecular Dynamics Simulation of Nanodroplet Evaporation," Journal of Heat Transfer, vol. 123, pp. 741-748, 2001.
  31. T. L. Kaltz, L. N. Long, M. M. Micci, and J. K. Little, "Supercritical Vaporization of Liquid Oxygen Droplets Using Molecular Dynamics," Combustion Science & Technology, vol. 136, pp. 279-301, 1998.
  32. G. A. Chapela, G. Saville, and J. S. Rowlinson, "Computer simulation of the gas/liquid surface," Faraday Discussions of the Chemical Society, vol. 59, pp. 22-28, 1975.
  33. G. A. Chapela, G. Saville, S. M. Thompson, and J. S. Rowlinson, "Computer simulation of a gas-liquid surface. Part 1," Journal of the Chemical Society Faraday Transactions, vol. 73, pp. 1133-1144, 1977.
  34. A. Benarous and A. Liazid, "H-2-O-2 SUPERCRITICAL COMBUSTION MODELING USING A CFD CODE," Thermal Science, vol. 13, pp. 139-152, 2009.
  35. J. Sarkar, "Improving thermal performance of microchannel electronic heat sink using supercritical CO2 as coolant," Thermal Science, vol. 23, pp. 30-30, 2017.
  36. H. Y. Yue and Z. G. Liu, "Viscosity prediction of refrigerants under subcritical/supercritical conditions," Thermal Science, vol. 19, pp. 1293-1296, 2015.
  37. W. L. Jorgensen, D. S. M. And, and J. Tiradorives, "Development and Testing of the OPLS All-Atom Force Field on Conformational Energetics and Properties of Organic Liquids," Journal of the American Chemical Society, vol. 118, pp. 11225-11236, 2017.
  38. M. J. P. Nijmeijer, A. F. Bakker, C. Bruin, and J. H. Sikkenk, "A molecular dynamics simulation of the Lennard‐‐Jones liquid--vapor interface," Journal of Chemical Physics, vol. 89, pp. 3789-3792, 1988.
  39. R. N. Dahms and J. C. Oefelein, "Non-equilibrium gas-liquid interface dynamics in high-pressure liquid injection systems," Proceedings of the Combustion Institute, vol. 35, pp. 1587-1594, 2013.
  40. R. N. Dahms, J. Manin, L. M. Pickett, and J. C. Oefelein, "Understanding high-pressure gas-liquid interface phenomena in Diesel engines," Proceedings of the Combustion Institute, vol. 34, pp. 1667-1675, 2013.

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