## Simulation of the Sedimentation of Melting Solid Particles

## Hui Gan, James J. Feng & Howard H. Hu

*Int. J. Multiphase Flow,* Vol. 29, pp.
751-769 (2003).

**Abstract - **This study is motivated
by the fact
that dispersed two-phase flows are often accompanied by interfacial
activities
such as chemical reaction and phase change. Toward an understanding of
the role of interfacial transport, we numerically simulate the
sedimentation
of melting solid particles in a Newtonian fluid. The fluid flow and
solid
motion determine the fluid-solid heat transfer and hence the melting
rate.
The thermal convection and interfacial morphology, in return, affect
the
motion of both phases. The two-dimensional Navier--Stokes and energy
equations
are solved at moderate Reynolds numbers by a finite-element method, and
the melting interface is determined from the local heat flux. The
motion
of each solid particle is tracked using an arbitrary
Lagrangian-Eulerian
scheme. Results show that the sedimentation of melting particles is
largely
governed by the competition between the upward flow of the warm
upstream
fluid and the downward flow of the cold melt. A single particle
settling
in a channel may be pushed away from the centerline toward the wall. A
pair of particles interact in a complex way, separating at low Grashof
number $Gr$ and attracting each other at high $Gr$. These results have
interesting implications for the formation of microstructures in
interfacially
active two-phase flows.