INVESTIGADORES
ARES Alicia Esther
congresos y reuniones científicas
Título:
Modeling the interaction of convex solidifying interfaces with spherical particles
Autor/es:
E. M. AGALIOTIS; M. R. ROSENBERGER; A. E. ARES; C. E. SCHVEZOV
Lugar:
Beijing, China
Reunión:
Conferencia; THE 16th INTERNATIONAL CONFERENCE ON CRYSTAL GROWTH (ICCG-16); 2010
Institución organizadora:
ICCG-16
Resumen:
The interaction of a foreign
particle with a solidifying interface which produces the phenomenon of pushing
is modeling numerically. This phenomenon is known to be affected by fluid flow,
thermal field, solute field and the nature of the particle, the melt and the
solid material and affects the distribution of the particles in the melt.
Particles with different thermal conductivities than the solid and melt produce
a convex or concave interface shape for particles with smaller or larger
conductivity than solidifying material, respectively.
In the present report the case of
particles generating a convex interface is considered. The thermal and fluid
field calculations are made in a decoupled way determining first the shape of
the interface, and then the two main forces acting during pushing; the drag and
repulsion forces are modeled. The thermal and fluid flow fields were calculated
using finite element methods.
Both, the drag and repulsion forces
are integrated at each step and compared until both are equal and the steady
state of pushing is reached. The pushing force is integrated using the Casimir-Lifshitz-van
der Waals interaction.
It was found that the model
predicts the equilibrium distance in a steady state of pushing for different
sizes of particles and a convex solidifying interface. It is shown that the
separation equilibrium distance for a convex interface with respect to an ideal
planar interface results in a larger solidification velocity for trapping. The
model results were in good agreement with experimental results for the critical
velocity reported in the literature.