Fully 3-D simulations of bursting bubbles and jet droplets: influence of surface rheology at large Bond number*

Aerosol droplets formed by the bursting of bubbles at a liquid-gas interface are at the core of a wide range of natural processes, everyday activities, and high-end applications. In natural flows, these ejected drops carry various contaminants (e.g., biological materials and toxic chemicals) which frequently exhibit surface-active properties and induce complex interfacial phenomena. We study the sub-stages of bubble collapse, jet ascent, and droplet ejection through high-fidelity 3-D numerical simulations that explicitly couple the dynamic transport and exchange of surfactants between the liquid bulk phase and the interface. We specifically focus on a few crucial yet often overlooked aspects of the system, including the individual and combined role of surface viscoelasticity and Marangoni stresses under non-negligible Bond (Bo > 0.1) number conditions. Our results suggest that notable non-axisymmetric flow features develop as capillary waves propagate through the bursting bubble and create the rising jet, highlighting the critical importance of conducting fully three-dimensional simulations for a comprehensive understanding of these systems. Furthermore, we reveal that the influence of gravity extends beyond the equilibrated bubble morphology prior to its collapse, remaining an active element influencing the jet’s dynamics. Finally, we explore in detail the physical mechanisms underlying previously reported events of surfactant-induced wave damping and jet end-pinching suppression.