LBM–PFM simulation of directional frozen crystallisation of seawater in the presence of a single bubble

In this study, the effect of single bubble behaviour on seawater-frozen crystallisation was investigated using the lattice Boltzmann method–phase field method (LBM–PFM) coupled method at the pore scale. First, a new LBM–PFM model is proposed and validated. Second, the coupled model is applied in the simulation of the crystallisation process in two-phase (seawater–bubble) fluids. In addition, the effects of the bubble radius, bubble velocity and bubble position are discussed numerically. The results show that the existence of bubbles can effectively promote the growth of ice crystals and increase the crystallisation rate by 6.78 %. Moreover, the effect is strengthened with increasing bubble radius and decreasing its distance from the heat source. In addition, the effect of bubble velocity on the crystallisation velocity varies nonlinearly with time. •A new LBM–PFM model based on free energy theory is proposed and validated.•The crystallisation process in two-phase (seawater–bubble) fluids is simulated.•The effects of the bubble radius, bubble velocity and bubble position are discussed numerically