Mesoscopic modeling of interaction dynamics for two bubbles in the near-wall region

A nonorthogonal hybrid thermal lattice Boltzmann cavitation model is proposed in this study. The flow and density field are described by the pseudopotential model, while the temperature is realized by solving the macroscopic temperature function. The model is verified by simulating the Laplace law and a bubble evolves in the unbounded region. Furthermore, the interaction dynamics between two bubbles near the wall are investigated. The bubble collapse intensity is dominated by the initial bubble-bubble distance and bubble-wall distance. A pair of inclined reentrant jets are reported for the strong interaction modes, and splashing resulting from the jet collisions may lead to the bubble center shifting away from the wall or the axis of symmetry. For the weak interaction mode with dimensionless bubble-wall distance gamma between 1 and 3.5, the maximum collapse pressure increases linearly. The maximum collapse pressure Pcmax decreases with increasing bubble spacing, and Pcmax for distance between two bubbles with d2 = 40 lu increases by 9 % to 16.2 % compared to that of d2 = 30 lu. The variation of the liquid film thickness h between adjacent cavitation bubbles is primarily governed by the expansion velocity of the bubble wall (h) over dot, and similarly, the thickness of the liquid film between the bubble wall follows the same principle with h similar to(h) over dot(-2). The bubble radius in the growth stage aligns closely with the theoretical analysis for the weak interaction mode, while discrepancies appear between the simulation and prediction due to the bubble losing its roundness in the collapse stage.