Semisharp phase field method for quantitative phase change simulations

The standard phase field model for simulation of phase change requires an asymptotic analysis in a vanishing interface width, in order to connect the model parameters to the sharp interface parameters, which has hampered the quantitative usefulness of the method. In this Letter the method is simplified to the point that the relevant reduced problem can be solved analytically, allowing the sharp and phase field parameters to be identified, in principle, without restrictions on the model parameters. The scheme is tested for standard cases of two-dimensional solidification, showing excellent agreement with sharp interface kinetics.