Bubble puzzles: From fundamentals to applications

Abstract

For centuries, bubbles have fascinated artists, engineers, and scientists alike. In spite of century-long research on them, new and often surprising bubble phenomena, features, and applications keep popping up. In this paper I sketch my personal scientific bubble journey, starting with single bubble sonoluminescence, continuing with sound emission and scattering of bubbles, cavitation, snapping shrimp, impact events, air entrainment, surface micro-and nanobubbles, and finally coming to effective force models for bubbles and dispersed bubbly two-phase flow. In particular, I also cover various applications of bubbles, namely in ultrasound diagnostics, drug and gene delivery, piezo-acoustic inkjet printing, immersion lithography, sonochemistry, electrolysis, catalysis, acoustic marine geophysical survey, and bubble drag reduction for naval vessels, and show how these applications crossed my way. I also try to show that good and interesting fundamental science and relevant applications are not a contradiction, but mutually stimulate each other in both directions.

Oscillating Hydrogen Bubbles at Pt Microelectrodes

“…Both the critical carpet thickness at detachment and the oscillation frequencies of the bubble as predicted by the model agree well with the experiment. The growth of gas bubbles is a ubiquitous phenomenon in nature and engineering [1]. Impressive examples are related to sonoluminescence [2,3] or cavitation phenomena [4][5][6] or even the evolution of CO 2 bubbles in champagne [7].…”

“…This E y ðθÞ behavior results in a variation of F e with δ, i.e., F e ðδÞ ¼ 2πσR 2 R π 0 E y ðθ; δÞ sin θdθ, where dA ¼ 2πR 2 sin θdθ is substituted in Eq. (1).…”

Inkjet Nozzle Failure by Heterogeneous Nucleation: Bubble Entrainment, Cavitation, and Diffusive Growth

“…The translational paths of the nucleated bubbles can be qualitatively explained by a combination of acoustic radiation forces and hydrodynamic forces [32,52,53]. The freshly nucleated bubble is pushed into the ink channel by two mechanisms.…”

Bubbly and Buoyant Particle–Laden Turbulent Flows

“…A remarkable effect of introducing bubbles in turbulent TC flow is that with only a small percentage (α ∼ O(1%)) of bubbles, significant turbulence modulation can be achieved. This usually manifests in major drag reduction, with various mechanisms contributing to it, see also section 9 of Lohse (2018).…”

“…The vast majority of these have been on neutrally buoyant and heavy particles. As we will discuss in this review, for a variety of reasons, the heavy and neutrally buoyant particle laden flows are experimentally, numerically, and theoretically more amenable as compared to their bubble laden counterparts (Lohse 2018). Balachandar and Eaton (2010) presented the most recent review discussing important aspects of turbulent bubbly flows.…”