Alternatively, it is possible to develop predictive numerical
models assessing permeability as detailed in Refs.
[25,26]. Numerical models solve the Stokes equations for
a domain representing the interdendritic liquid. The obvious
advantage of using a simulated microstructure is that
the evolution of permeability with solid fraction can be
easily studied for different grain sizes and morphologies.
However, the main challenge with this method is the geometry
of the domain itself. Since permeability is a characteristic
of porous media that is based on the geometry of the
flow channels, i.e. channel width, surface area and tortuosity,
an accurate computational domain is critical for
numerical determination of this parameter [27].