A concise and stable macro segregation simulation model applicable to channel segregation prediction has been proposed. In flow analysis, thermosolutal convection and Darcy's flow were considered. The Darcy term in the momentum equation was stabilized by using the implicit discretization technique. The effect of solute movement at solid/liquid interface was simply formulated by jump condition. With these models, parallel plate flow in porous media problem was analyzed. Results of this stabilized method had excellent agreement with analytical solution and it was shown that the method has good convergence in pressure linear equation. Since time increment is not restricted by Darcy term in the stabilized analysis, the calculation time of the stabilized method was much shorter than the conventional explicit discretization method. For verifying usefulness of the simulation method for macro segregation, the horizontal directional solidification of Sn-10wt%Bi alloy was analyzed and compared with the experimental results by Quillet et al. The regions where channel segregation occurred and tendency of Bi concentration at the bottom of the ingot were found to agree well with the experimental results. The calculation time was as short as and more or less equal to the solidification time in the simulation.
