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Giant bubble pinch-off

Raymond Bergmann·Devaraj van der Meer·Mark Stijnman·Marijn Sandtke·Andrea Prosperetti·Detlef Lohse
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Abstract

Self-similarity has been the paradigmatic picture for the pinch-off of a drop. Here we will show through high-speed imaging and boundary integral simulations that the inverse problem, the pinch-off of an air bubble in water, is not self-similar in a strict sense: A disk is quickly pulled through a water surface, leading to a giant, cylindrical void which after collapse creates an upward and a downward jet. Only in the limiting case of large Froude number the neck radius $h$ scales as $h(-\log h)^{1/4} \propto τ^{1/2}$, the purely inertial scaling. For any finite Froude number the collapse is slower, and a second length-scale, the curvature of the void, comes into play. Both length-scales are found to exhibit power-law scaling in time, but with different exponents depending on the Froude number, signaling the non-universality of the bubble pinch-off.

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Raymond Bergmann, Devaraj van der Meer, Mark Stijnman, Marijn Sandtke, Andrea Prosperetti, Detlef Lohse. 2006-01-24. Giant bubble pinch-off. https://doi.org/10.1103/physrevlett.96.154505

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