Simulations on Ostwald Ripening by Using Lattice Boltzmann Methods

Lattice Boltzmann methods have solid basis of particle kinetics, and it can be extended to simulations for multiphase flows by simply adding inter-particle forces. It is proven that it shares common fundamentals with thermodynamic models, saying phase field model. Growth of bubbles is simulated by Shan-Chen multiphase lattice Boltzmann methods (SC-LBM). The tests for single and dual bubble growth show SC-LBM simulation agrees with Rayleigh-Plesset predictions, which is applied widely for cavitating phenomena. Further tests for a cluster of bubbles show that such processes fulfill reaction-limited phase separation (coarsening), one of the important regimes of Ostwald ripening. During the processes, a thermal equilibrium is reached, while the interfacial energy keeps decreasing. The phenomenon of larger bubble eating smaller bubble can be well captured. The results also show that the R ̅∼t^(1/2) and N∼t^(-1) scalings are well satisfied, where R ̅, N and t are the averaged bubble size, bubble number and time, respectively. We believe SC-LBM has great potential to be applied in both mechanical and chemical circumstances.