A computational fluid dynamics method for multi-oscillation collapse of spherical cavitation bubbles

Abstract

Accurately predicting spherical bubble dynamics over multiple oscillation cycles remains challenging in CFD (computational fluid dynamics). In this paper, a new method is proposed. Mass conservation is enforced, and the volume fraction is limited by a threshold to ensure numerical stability. A pressure factor is introduced in this method to account for vapor condensation. When the bubble reaches the maximum radius in an oscillation, the pressure in the bubble is modified by dividing the value by the pressure factor, which can be estimated by Rn values used in the extended Gilmore model. The method is applied to the cases with spherical bubble collapse during four oscillations in infinite still water, with millimeter and micrometer bubble sizes. The shock wave radius and the induced pressure field after the first collapse by CFD are also consistent with the results predicted by the extended Gilmore model. The proposed method is easy to implement in CFD programs and can be used for various applications relating to spherical bubble with multi-oscillation collapse.