Like 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.