Influence of the phase interface mass transfer characteristics on the cavitation bubble collapse in water

Abstract

The dependence of cavitation bubble collapse on such characteristics of the mass transfer across the bubble surface as the phase interface temperature jump, the ratio of the interface displacement speed due to the mass exchange to the speed of the thermal motion of the vapor molecules, the difference between the evaporation and condensation coefficients on the cavitation bubble collapse in water is studied. The evaporation and condensation coefficients range from 0.002 to 0.2. In the numerical technique, the dynamics of the vapor in the bubble and the surrounding liquid is governed by the gas dynamics equations closed with wide-range equations of state. Evaporation and condensation are described by the Hertz–Knudsen–Langmuir expressions. It has been found that the influence of the mass transfer characteristics considered is insignificant at small values of the evaporation and condensation coefficients, and monotonically grows with their increasing. In particular, the vapor mass in the bubble at the end of collapse is underestimated by 10% if the temperature jump is not taken into account, is overestimated by 20% if non-zero ratio of the interface displacement speed due to mass exchange to the thermal motion speed of vapor molecules is ignored and is overestimated by 80% if the difference between the evaporation and condensation coefficients is not allowed for. Similar errors in the maximum pressure in the bubble during its collapse can reach 10%, 15% and 35%, respectively.