multiphase flow, solute and particle transport processes
are naturally suited to network modeling. Network models
cannot capture streamline-scale behavior; yet, they are
highly successful when used in appropriate situations.
One of the main limitations is the inability to model
the continuity of streamlines through the pore space,
which affects flow at moderate to high Peclet numbers or
in cases where long spatial correlations exist in the
flow field. Not enough is known about these limitations
to understand when they become consequential and what
techniques are best able to address them.
The graphics above show an
experimental RTD from a heterogeneous packed bed on the
left (from Oliveros and Smith, AIChE J., 28(5), 751
(1982)). On the right is a quantitative network-model
simulation of the same experiment, with no adjustable
parameters. Current work on particle transport includes
the simulation of particle retention and fouling in
microfiltration membranes. The aim of the research is to
improve the link between microscale structure and
macroscopic performance in the membranes.