Molecular dynamics computer simulation technique has been applied to investigate fluid phase change mechanisms near vapor-liquid interfaces. The simulation enables us to estimate the most relevant parameter, condensation coefficient α
c, which is the ratio of condensation flux to vapor collision flux. We found: (i) α
c is less than unity even for simple fluids, and α
c of associating fluids is much less than that. (ii) There is a strong temperature dependence of α
c. (iii) Under the nonequilibrium condition, α
c depends also on the density (or pressure) and the temperature of the vapor. A simple evaporation model based on a transition state theory can explain this behavior to some extent. As related topics, molecular dynamics of nucleation processes is also described.
抄録全体を表示