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Simulation of convection effects on dendritic growth
by
Gustav Amberg
Department of Mechanics, KTH, Stockholm, Sweden
Coauthors: Robert Tönhardt
Phase field simulations have been used to study the evolution from a small nucleus to a dendrite in an undercooled melt, in the presence of convection in the melt. As a generic case for growth from solid boundaries, the nucleus is in one case assumed to be attached to a solid wall, and a shear flow parallell to the wall is assumed in the melt. The interaction between the melt flow and the growing dendrite results in a changed growth rate and morphology. One aspect that has been investigated is how the effective tilting of the main stem of the dendrite depends on the flow strength.
It is shown that the major factor that determines the tilt angle is the selection of a nucleus with an optimal initial crystal orientation. We have also studied natural convection around a nucleus held in an undercooled melt. The phase field equations are solved together with the equations for viscous fluid flow using an adaptive finite element method. This method allows a large computional domain, so that a single dendrite in an effectively unbounded region can be studied.
Date received: March 26, 1999
Copyright © 1999 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caco-25.