The interaction between bubbles and particles/bubbles is critical to marine engineering problems such as propeller cavitation and explosion protection. To address these challenges, an improved lattice Boltzmann model capable of handling high density ratios and complex interfaces is developed. Based on this model, a three-dimensional gas–liquid–solid coupling framework is established. Numerical simulations indicate that in bubble–particle coupling, coaxial conditions induce jet penetration and the formation of a stable bubble ring. In contrast, asymmetric conditions lead to interface stretching, flow around, and encapsulation failure. In bubble–bubble coupling, the system exhibits a continuous behavioral spectrum ranging from symmetrical synergistic coalescence to eccentric delayed coalescence, with the dominant mechanism transitioning as the feature size ratio (γ) and the initial positions (Δ) vary. Specifically, when γ1, the dominant mechanism shifts from flow-field attraction to buoyancy competition. Mechanistic analysis clarifies that the former is governed by external rigid constraints, exhibiting a unidirectional response, whereas the latter is dominated by interface attraction and cooperation, showing a bidirectional response. The study further quantifies that the formation efficiency of the ring structure decreases with increasing γ, while the coalescence time increases with γ and Δ, demonstrating a cooperative suppression effect. From the perspective of the mechanistic opposition between external constraints and internal cooperation, this work elucidates the physical nature of the two types of interactions, providing a theoretical basis for mechanistic analysis and engineering regulation of related multiphase flow systems.
Wang et al. (Wed,) studied this question.