Strain-induced yielding in bubble clusters

Area of Science:

• Fluid dynamics
• Soft matter physics
• Interfacial phenomena

Background:

• Bubble clusters are common in industrial processes and natural phenomena.
• Understanding bubble cluster behavior under stress is crucial for process optimization and safety.

Purpose of the Study:

• To investigate the yielding behavior of two- and four-bubble clusters under shear.
• To determine the critical deformation leading to bubble separation or topological rearrangement.
• To establish yield criteria in both quasistatic and dynamic regimes.

Main Methods:

• Experimental measurements of critical deformation under varying shear rates, liquid compositions, and liquid content.
• Computational simulations to complement experimental data.
• Derivation of a scaling law for dynamic yielding based on meniscus rupture dynamics.

Main Results:

• A geometrical yield criterion was established for the quasistatic case.
• In the dynamic regime, critical deformation increases with strain rate.
• A universal scaling law was derived and experimentally validated for two- and four-bubble clusters, based on inertial rupture of the liquid meniscus.

Conclusions:

• The study provides a comprehensive understanding of bubble cluster yielding under shear.
• The derived scaling law offers a predictive tool for dynamic bubble cluster behavior.
• Findings are applicable to systems with varying numbers of bubbles.