Giant Bubble Pinch-Off


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 numbers does the purely inertial scaling h(?log h)1/4??1/2 for the neck radius h [J.?M. Gordillo et al., Phys. Rev. Lett. 95, 194501 (2005)] become visible. 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 nonuniversality of the bubble pinch-off.





Copyright 2006 Physical Review Letters. Recommended citation: Bergmann, Raymond, Devaraj van der Meer, Mark Stijnman, Marijn Sandtke, Andrea Prosperetti, and Detlef Lohse. "Giant bubble pinch-off." Physical review letters 96, no. 15 (2006): 154505. DOI: 10.1103/PhysRevLett.96.154505 URL: Reproduced in accordance with the original publisher’s licensing terms and with permission from the author(s).