multibubble

Multibubble describes a system in which many gas-filled bubbles are dispersed within a liquid. The bubbles interact through fluid flow, surface tension, and gas exchange, producing collective dynamics that differ from those of an isolated bubble. Multibubble configurations occur in foams, bubble columns, boiling liquids, sonicated liquids, and cavitation clouds, and can span a range of size scales from micrometers to millimeters. The size distribution and spatial arrangement influence stability, coalescence, and transport properties of the mixture.

Typical bubbles may be spherical at small sizes, but interactions with neighbors or boundaries can distort shapes. Formation mechanisms include homogeneous and heterogeneous nucleation under supersaturation or rapid pressure changes, boiling, degassing, mechanical agitation, and ultrasonic irradiation. Gas transfer between the liquid and bubbles, via diffusion, growth or dissolution, alters the size distribution over time; Ostwald ripening can cause larger bubbles to grow at the expense of smaller ones.

Dynamics in a multibubble system are governed by inter-bubble hydrodynamic interactions and external forcing. In quiescent liquids, coalescence, fragmentation, and dissolution modulate the ensemble. Under acoustic fields, bubbles oscillate and exert secondary forces that can attract or repel neighbors, promoting clustering or dispersion. Modeling approaches often extend single-bubble descriptions, such as the Rayleigh-Plesset equation, to many-body frameworks and population balance analyses.

Applications and relevance span industrial and scientific contexts, including foaming and flotation processes, gas-liquid reactors like bubble columns, material processing through foaming, and medical imaging where microbubble suspensions serve as ultrasound contrast agents. Multibubble phenomena are also central to understanding cavitation, sonochemistry, and related fluid-dynamics problems.