A study on the growth of cavitation bubble nuclei using large-scale molecular dynamics simulations

Abstract

We have investigated the growth mechanism of cavitation bubble nuclei and a power law dependence with time for the growth of the mean radius using microcanonical molecular dynamics simulations. A competing growth process was observed in the case of a one-component liquid, while frequent coalescence was observed in the case of a two-component liquid in which a dissolved noncondensable gas forms bubble nuclei. Although nearly the same growth exponent (close to 12) was obtained, we found that the different characteristic in the growth is reflected to a power law for the change of the total radius (α) and that for the change of the number of bubble nuclei (β), where α reflects a characteristic of the time development of the void fraction while β reflects a characteristic collapsing or coalescence speed. The difference in these two parameters is originated from the faster pressure propagation in the one-component fluid and the slower diffusion process of the noncondensable gas in the two-component fluid.