Molecular Dynamics Study of Motion of Impurities in Liquid

Abstract

Heterogeneous bubble nucleation in liquid oxygen including helium or nitrogen is simulated by usint the molecular dynamics method. Molecular interaction is given as Lennard-Jones potential, and each potential parameter is determined so that it well expresses the thermodynamic properties of factual fluids. In the case that helium is the impurity, clustering of helium molecules is observed through the simulation and these clusters are considered to become bubble nuclei. On the other hand, nitrogen molecules do not make a cluster in liquid oxygen under the same condition, and bubble is formed based on the density fluctuation as same as unary liquid oxygen. Therefore, helium in the liquid oxygen has a fairly stronger action to make clusters as bubble nuclei.