Phase-field modeling of reactive fluid with solute precipitation and dissolution

A phase-field approach to the dynamics of liquid-solid interfaces that evolve due to solute precipitation and/or dissolution will be presented.In contrast to solidification processes controlled by a temperature field that is continuous across the solid/liquid interface (with a discontinuous temperature gradient), precipitation/dissolution is controlled by a solute concentration field that is discontinuous at the solid/liquid interface. A sharp-interface asymptotic analysis of the phase-field equations was performed for precipitation/dissolution processes to demonstrate that the phase-field equations converge to the proper sharp-interface limit. The mathematical model was validated by numerically solving the coupled phase-field equations for one- and two- dimensional precipitation/dissolution problems and by comparison with analytical solutions. The diffusion-limited aggregation (DLA) process was modeled with the phase field method, and the pattern generated in this manner resembled clusters generated by the classical Witten- Sander particle-cluster diffusion-limited aggregation model and has a fractal dimensionality of 1.68.