Bubble splitting in oscillatory flows on ground and in reduced gravity

The stability of centimeter scale air bubbles is studied in quiescent suspending liquid under
an imposed oscillatory acceleration field. Experiments were performed in reduced- and normal-gravity
environments. A strong acceleration resulted in an instability leading to the breakups of the bubbles in
both gravity environments. The breakup onset was investigated and found to be characterized by a critical
acceleration acr . The influence of the liquid viscosity and the gravitational environment was studied.
Empirical correlations for the onset are presented and discussed with the intention to reveal splitting
mechanism. The inertial mechanism often deemed to cause the breakup of drops sub jected to a rapid
gas stream is shown to give explanations consistent with the experiments. A breakup criterion for both
gravitational environments is proposed through discussions from an energetic point of view.