Crown formation from a cavitating bubble close to a free surface

Abstract

A rapidly growing bubble close to a free surface induces jetting: a central jet protruding outwards and a crown surrounding it at later stages. While the formation mechanism of the central jet is known and documented, that of the crown remains unsettled. We perform axisymmetric simulations of the problem using the free software program basilisk, where a finite-volume compressible solver has been implemented, that uses a geometric Volume-of-Fluid method (VoF) for the tracking of the interface. We show that the mechanism of crown formation is a combination of a pressure distortion over the curved interface, inducing flow focusing, and of a flow reversal, caused by the second expansion of the toroidal bubble that drives the crown. The work culminates in a parametric study with the Weber number, the Reynolds number, the pressure ratio and the dimensionless bubble distance to the free surface as control parameters. Their effects on both the central jet and the crown are explored. For high Weber numbers, we observe the formation of weaker "secondary crowns", highly correlated with the third oscillation cycle of the bubble.

References in corpus (3)

• Scaling laws for jets of single cavitation bubbles
• Shock waves from non-spherical cavitation bubbles
• Cavitation Bubble Dynamics inside Liquid Drops in Microgravity

Cited by in corpus (7)

• A unified theory for bubble dynamics
• Theoretical study on bubble dynamics under hybrid-boundary and multi-bubble conditions using the unified equation
• On the dynamics of a collapsing bubble in contact with a rigid wall
• A multigrid solver for the coupled pressure-temperature equations in an all-Mach solver with VoF
• Finite speed of sound effects on asymmetry in multibubble cavitation
• A Review of the Accuracy of Direct Numerical Simulation Tools for the Simulation of Non-Spherical Bubble Collapses
• Boundary vorticity dynamics of two-phase viscous flow