Computational Mathematics Group, Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
J Chem Phys. 2011 Jan 28;134(4):044137. doi: 10.1063/1.3537973.
Two-dimensional dendritic growth due to solute precipitation was simulated using a phase-field model reported earlier [Z. Xu and P. Meakin, J. Chem. Phys. 129, 014705 (2008)]. It was shown that diffusion-limited precipitation due to the chemical reaction at the solid-liquid interface has similarities with diffusion-limited aggregation (DLA). The diffusion-limited precipitation is attained by setting the chemical reaction rate much larger compared to the solute diffusion to eliminate the effect of the interface growth kinetics. The phase-field simulation results were in reasonable agreement with the analytical solutions. The fractal solid fingers can be formed in the diffusion-limited precipitation and have a fractal dimension measured d(f)=1.68, close to 1.64, the fractal dimensionality of large square lattice DLA clusters.
使用之前报道的相场模型模拟了由于溶质沉淀导致的二维枝晶生长[Z. Xu 和 P. Meakin, J. Chem. Phys. 129, 014705 (2008)]。结果表明，由于固液界面上的化学反应导致的扩散限制沉淀与扩散限制聚集（DLA）具有相似性。通过将化学反应速率设置得远大于溶质扩散速率，可以消除界面生长动力学的影响，从而实现扩散限制沉淀。相场模拟结果与解析解吻合较好。在扩散限制沉淀中可以形成分形固体指，其分形维数测量值为 d(f)=1.68，接近大正方形晶格 DLA 团簇的分形维数 1.64。
