Dynamics of tandem bubble interaction near tissue

A high-fidelity multiphase flow computational model is utilized to investigate the interaction mechanism between anti-phase tandem bubbles and tissue materials in a free-field environment. The formation of liquid jets generated by tandem bubble coupling and its effects on tissue deformation are analyzed. Parametric studies are conducted to explore the impacts of bubble–bubble distance (γbb), bubble size ratio (Sbb), and bubble–tissue distance (γtb). The results indicate that the regime of tissue penetration varies under different γbb. For small γbb, the tissue deformation is mainly attributed to the stretching of upper bubbles and liquid jets; whereas for large γbb, tissue deformation is primarily induced by the jets themselves; and for moderate γbb values, it is caused by a combined effect involving both jets and the evolution of toroidal bubbles. Comparative analysis shows the significant impact of varying Sbb on bubble coupling dynamics, with larger Sbb values correlating with more potent tissue penetration. Furthermore, the study also reveals that, beyond γtb exceeding 3, penetration ceases to manifest, advocating for the maintenance of γtb below 1.4 for practical applications.