Numerical study on formation of a splash sheet induced by an oscillating bubble in extreme vicinity to a water surface

When it is generated in extreme vicinity to a water surface, an oscillating bubble bursts into the atmosphere and high-pressure gas is simultaneously exhausted from it, forming a splash sheet and an open cavity. The dynamics of the splash sheet induced by the bursting of the oscillating bubble has drawn increasing attention, but it is not clearly understood. We conduct a numerical simulation in the framework of open-source software OpenFOAM. The volume of fluid and Reynolds-Averaged Navier-Stokes methods are used to precisely capture the gas-liquid interface and obtain flow structure, respectively. In addition, an experimental setup is carried out based on an object distance compensation method for validation of the numerical model. Two patterns are summarized: (1) An open splash, (2) A sealed splash depending on whether a splash sheet completely closes. Detailed numerical results shows that the bubble bursting is induced by the Rayleigh-Taylor instability. Finally, the splash closures are discussed for two patterns.

Automated summary

When an oscillating bubble bursts near a water surface, it releases high-pressure gas and forms a splash sheet and an open cavity. The dynamics of the splash sheet resulting from the bursting of the oscillating bubble are still not well understood. In this study, we conduct numerical simulations using OpenFOAM software to accurately capture the gas-liquid interface and flow structure. Experimental validation is also performed. Two patterns of splash closures, open and sealed, are identified based on whether the splash sheet completely closes. The Rayleigh-Taylor instability is found to induce the bubble bursting.