Abstract: The complex multiphase flow system was simulated by the Lattice Boltzmann Method based on Shan-Chen multiphase flow to explore the growth and motion of bubbles in the liquid phase. The interaction between dendrites and bubbles during solidification of Al-4.0wt% Cu alloys was studied, along with the effect of anisotropy on solidification organization and the variation in solution density when dendrites coexist with bubbles. The results showed that in the directional solidification dendrite growth model, the bubbles initially precipitate at the bottom of the dendrite. Pressure differentials drive bubble ascent, leading to interactions with dendrites during flow, resulting in instances of bubble coalescence and disappearance. In densely channeled regions between dendrites,larger bubbles become worm-shaped. The height-to-length ratio of the simulated area affects the growth of dendrites and bubbles, and the short, small bubbles more is likely to be produced when the height-to-length ratio is small, but the worm-like bubbles more is likely to be produced when the height-to-length ratio is large. In the isometric dendrite growth model, bubbles are precipitated between the dendrites, as the dendrites grow, they also merge, disappear and undergo deformation when they are squeezed.

Key words: phase-field simulation, Lattice Boltzmann method, bubbles, Al-4.0wt% Cu alloy