Phase-field simulation of dendritic growth in a shear flow

Abstract

We study how the dendritic evolution of an initially small nucleus is affected by a mean external flow. The nucleus is considered to be attached to a solid wall, and it grows away from the wall into the melt. The melt is assumed to be flowing due to an applied shear stress far away from the wall. The fluid flow alters the local heat transfer at the solidification front, and thus the shape of the dentrite. Due to the flow the nucleus evolves to an asymmetric dentrite that tilts. Another effect of the flow is that the sidebranch-growth gets promoted and inhibited on the upstream and downstream side, respectively. We use an adaptive grid and finite element applied to the phase-field method in 2D. The adaptivity results in a high local resolution at the solidification front and a much coarser mesh away from the front.