Open AccessA molecular dynamics investigation on fuel vaporization and mixing characteristics under sub/supercritical conditions
Author(s) -
Wei Wu,
Tingyu Zhou,
Lun Zhao,
Lei Ddeng,
Maozhao Xie
Publication year - 2022
Publication title -
thermal science/thermal science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.339
H-Index - 43
eISSN - 2334-7163
pISSN - 0354-9836
DOI - 10.2298/tsci210201335w
Subject(s) - supercritical fluid , vaporization , evaporation , materials science , mixing (physics) , molecular dynamics , thermodynamics , liquid gas , heptane , enthalpy of vaporization , ambient pressure , nitrogen , chemistry , organic chemistry , physics , computational chemistry , quantum mechanics , enthalpy
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 to turbulent mixing process.