DOI: 10.1615/ICHMT.2009.TurbulHeatMassTransf
ISBN Print: 978-1-56700-262-1
ISSN: 2377-2816
Solidification of a binary metal alloy in a turbulent melt flow driven by AC magnetic fields
SINOPSIS
In this work we numerically study the impact of Taylor-Görtler vortices inside a melt, driven by a rotating magnetic field, on the macrosegregation and the shape of the mushy zone during unidirectional solidification of Al-7wt%Si alloy. The weakly turbulent flow was modeled by means of direct numerical simulations in an axisymmetric approach, where the transient heat and mass transfer were simulated by means of a standard mixture model. Both types of solidification, columnar and equiaxed, were considered by the application of both a permeability and a hybrid model to treat the fluid flow in the mushy zone. Our results demonstrate that in the case of columnar solidification the Taylor-Görtler vortices cause both a wavy shape of the mushy zone and segregations in the form of a fir tree with a distinct accumulation of silicon along the axis of the cylinder.