Growth by rectified diffusion of strongly acoustically-forced gas bubbles in nearly saturated liquids

Olivier Louisnard (1) , Francisco Gomez (2)

1 RAPSODEE - Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement
2 Laboratorio de Ultrasonidos (Santiago de Chile, Chile)

The growth or dissolution of small gas bubbles (R0 < 15 μm) by rectified diffusion in nearly satu- rated liquids, subject to low frequencies (20 kHz < f < 100 kHz), high driving acoustic fields (1 bar < p < 5 bar) is investigated theoretically. It is shown that, in such conditions, the rectified diffusion threshold radius merges with the Blake threshold radius, which means that a growing bubble is also an inertially-oscillating bubble. On the assumption that such a bubble keeps its integrity up to the shape instability threshold predicted by single-bubble theory, a numerical estimation, and a fully analytical approximation of its growth-rate are derived. From one hand, the merging of the two thresholds raises the problem of the construction and self-sustainment of acoustic cavitation fields. From the other hand, the lifetime of the growing inertial bubbles calculated within the present the- ory is found to be much shorter than the time necessary to rectify argon. This allows an alternative interpretation of the absence of single-bubble sonoluminescence (SBSL) emission in multi-bubble fields, without resorting to the conventional picture of shape instabilities caused by the presence of other bubbles.

Mots clés: Bubble dynamics; Acoustic cavitation; Sonoluminescence; Rectified diffusion

Domaines: Physique [physics]

Olivier Louisnard, Francisco Gomez. Growth by rectified diffusion of strongly acoustically-forced gas bubbles in nearly saturated liquids. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2003, vol. 67 (n° 3), pp. 036610. ⟨10.1103/PhysRevE.67.036610⟩. ⟨hal-01343141⟩