17.2 Limitations

As mentioned in Section  17.1, the formulation in ANSYS FLUENT can be used to model the solidification/melting of pure materials, as well as alloys. ANSYS FLUENT offers two rules to determine the liquid fraction versus temperature relationship, namely the linear Lever rule and the non-linear Scheil rule.

The following limitations apply to the solidification/melting model in ANSYS FLUENT:

• The solidification/melting model can be used only with the pressure-based solver; it is not available with the density-based solvers.

• The solidification/melting model cannot be used for compressible flows.

• Of the general multiphase models (VOF, mixture, and Eulerian), only the VOF model can be used with the solidification/melting model.

• With the exception of species diffusivities, you cannot specify material properties separately for the solid and liquid materials.

• When using the solidification/melting model in conjunction with modeling species transport with reactions, there is no mechanism to restrict the reactions to only the liquid region; i.e., the reactions are solved everywhere.