Andrew Roosen's research

Much of Andy's research has to do with two-dimensional models of crystal growth using fully faceted crystals. This means that the wulff shape in a polygon, and the interfaces are also polygons having the same normals as are found in the Wulff shape. For more details about the computational scheme, look here.

The methods have been applied to a couple different types of motion. Here are some computations of a pure material solidifying from its melt. Click on the picture to see a brief movie.

The tips of the dendrite arms were 'pulsed' by raising the temperature at the tip by a very small amount periodically, resulting in the regular patterns. Red regions have been raised in temperature by the release of latent heat.

Andy has also done work with Craig Carter on calculations of interface motion by surface diffusion using the same basic technique.

Online Preprints

Shape Evolution by Surface Diffusion and Surface Attachment Limited Kinetics on Completely Faceted Surfaces, W. C. Carter, A. R. Roosen, J.W. Cahn, and J. E. Taylor.
Modeling Crystal Growth in a Diffusion Field Using Fully-Faceted Interfaces, A. R. Roosen, and J. E. Taylor.