Hybrid models of transport in crowded environments
- PI, NSF-EAR Sponsored Research, `Collaborative Research: Hybrid Modeling of Reactive Transport in Porous and Fractured Media (2013-Present);
- External Collaborator, Battelle Memorial Institute grant `Hydro-Biogeochemical Process dynamics in the Groundwater Surface Water Interaction Zone (2014-Present);
- Collaborator, DOE, Experimental Program to Stimulate Competitive Research Implementation Project “Radionuclide Waste Disposal: Development of Multi-scale Experimental and Modeling Capabilities” (2014-Present);
The term 'crowded environment' generally refers to a class of physical, engineering and biological systems characterized by a complex assembly of obstacles and pores. The pores are fully (or partially) saturated with a fluid in which solutes (e.g. contaminants, nutrients, ions) are dissolved. Examples of crowded environments include rock formations, fuel cells, cell membranes, and filters, just to mention a few. Modelling transport processes in crowded environments is a formidable task because of the hierarchy of scales that such complex heterogeneous systems exhibit. More often than not, physical and bio-geochemical phenomena on one scale (e.g., a pore scale) affect, and are coupled to, phenomena on a vastly different scale (e.g., a field scale).
For example, pore-scale molecular diffusion fundamentally affects field-scale mixing of (bio)chemically reacting solutes, and confined biomass growth can lead to appreciable reduction in field-scale hydraulic conductivity. Common features of such phenomena are their high localization (e.g., propagation of reactive fronts and biofilm growth) and/or strong nonlinear coupling between the processes involved. We tackle these processes by employing hybrid (multi-algorithm, multi-faceted) models which combine descriptions at different spatial and/or temporal scales in an efficient computational fashion. We are currently involved in the development of multiscale mathematics capabilities for a variety of different problems including mixing-induced precipitation fronts in porous and fractured media (NSF sponsored research), radionuclide transport (DOE-EPSCoR sponsored research) and biomediated transport in the hyporheic corridor (Battelle/PNL sponsored research).