The molecular dynamics method is employed to simulate the liquid-vapor nucleation processes. The results show that the initial stage of nucleus in nucleation process is cavity or space containing very few vapor molecules. Because of the very limited size of the simulation domain in previous reports, further growth of the nucleus has not been realized. Large scale molecular dynamics simulation of liquid-vapor nucleation indicates that the liquid-vapor nucleation process undergoes at least three stages: cavity growth, cavity coales-cence, bubble formation.
WANG Jinzhao, CHEN Min & GUO Zengyuan Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
By statistically analyzing the condensation process and reconsidering the transition state theory for condensation and evaporation, we first presented a completed theoretical formula of the condensation coefficient. Namely, the unknown parameters contained within the transition state theoretical calculation of the condensation coefficient are determined. The condensation coefficients calculated from this formula agree well with those from molecular dynamics simulations. With this formula, the classical expression of the condensation flux developed from the gas kinetic theory can be used to predict the condensation flux.
