Schematic presentation of an n-dodecane molecule (a) and its presentation using the united atom model (b). The bending angles between neighboring bonds (∼114°) (zigzag structure of the molecule) are taken into account.
Schematic presentation of the bonds and the interactions between atoms for a portion of the n-dodecane chain, consisting of four united atoms.
Snapshots of the simulation system: initial state (a) and liquid–vapor equilibrium (b).
Density profiles for temperatures 400 K, 450 K, 500 K, 550 K, and 600 K.
Liquid and vapor densities vs temperatures for n-dodecane at phase equilibria.
Local translational and rotational kinetic energies (normalized by ; see Table I) of n-dodecane molecules vs their positions along the x axis at 500 K for simulation boxes 51.39σ × 13.73σ × 13.73σ (a) and 137.04σ × 13.73σ × 13.73σ (b).
Local orientation parameter S(x) [see Eq. (5)] of n-dodecane molecules vs their positions along the x axis at 500 K.
The values of the evaporation/condensation coefficient for n-dodecane vs temperature, as predicted by the present molecular dynamic (MD) simulation and the transition state theory; the values of this coefficient for argon, water, and methanol, obtained by other authors, using MD simulations.
Schematic presentation of typical evaporation and condensation behaviors of simple molecules (a) and n-dodecane chains (b).
Typical trajectories of the centers of mass of n-dodecane molecules during spontaneous evaporation (a), reflection evaporation (b), spontaneous condensation (c), reflection condensation (d), and trapping-desorption evaporation/condensation (e) [see Fig. 9(b) for an explanation of the meaning of these terms].
Rescaled physical parameters used in the MD simulations.
Fractions of various condensation behaviors at T l = 500 K. The values in parentheses in , , and columns are the fractions of mass flux of spontaneous, trapping-desorption, and reflection condensations, respectively.
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