LBM simulation of bubble breakup dynamics in microchannels at large density ratios

This study develops a lattice Boltzmann model (LBM) that incorporates a Multi-Component Multi-Phase (MCMP) flow model with a Multi-Relaxation Time (MRT) collision operator to simulate bubble breakup in T-shaped microchannels accurately. This advanced LBM addresses the limitations of traditional methods in handling large density ratios, ensuring thermodynamic consistency and independent control of surface tension during bubble breakup. Observations reveal two distinct breakup behaviors: Type I bubbles maintain contact with the channel wall, initially driven by upstream pressure gradients and later by shear forces; in contrast, Type II bubbles do not contact the wall, and inertial forces hasten their breakup and expansion in a two-phase process. The study highlights the crucial role of liquid viscosity in accelerating bubble neck thinning beyond a critical point. This MCMP-MRT model offers significant insights for optimizing microfluidic system designs by elucidating bubble breakup dynamics.