Molecular Dynamics Study of Heterogeneous Bubble Nucleation in Liquid Oxygen Including Helium, Nitrogen, or Argon

Heterogeneous bubble nucleation in liquid oxygen including helium, nitrogen, or argon is simulated by using the molecular dynamics method. Molecular interaction is given as Lennard-Jones potential, and, basically, each potential parameter is determined so that a saturation curve obtained by MD data is consistent with an experimental value. In the case that helium is the impurity, a bubble is caused by density fluctuation at a lower concentration, while clusters of helium molecules become bubble nuclei at a higher concentration, and the point of bubble formation moves closer to the saturation point of pure oxygen when they form clusters. In the case that nitrogen or argon is the impurity, the above-mentioned clustering is not observed at a concentration where helium makes clusters, and these impurities have weaker action to make clusters compared with helium.