Level set method is an appropriate mathematical tool for solving two-phase
flow problems. It is used here for the first time to track the interface ev
olution during the process of casting a second alloy into mold, partly disp
lacing the first to achieve a casing with a different alloyed skin. Project
ion method for Navier-Stokes equations was adopted and the algorithm was im
plemented in finite element method. The numerical example shows that though
in those cases where the layer of liquid metal above is lighter than that
below, the interface is not always stable for density ratios less than one
of the two liquid metals. The stability of the interface is sensitive to th
e density ratio and inlet velocity and relatively insensitive to the viscos
ity ratio or other parameters. It is believed that level set method has pot
ential to be further used in real double casting processes. (C) 2001 Elsevi
er Science B.V. All rights reserved.