Water Resources Research Act Program

Details for Project ID 2020FL233B

Computational fluid dynamics as a tool for urban water particulate transport and fate during infiltration through permeable systems

Institute: Florida
Year Established: 2020 Start Date: 2020-03-01 End Date: 2021-02-28
Total Federal Funds: $29,957 Total Non-Federal Funds: $52,051

Principal Investigators: John Sansalone

Project Summary: Engineered permeable pavement systems date back to at least the period of the Roman Empire, primarily as a drainable all-weather surface to support existing modes of transport. Beyond the structural requirements for the current modes of modern transport an increasing consideration for implementation of passive permeable systems as an interface of the urban water cycle (whether rainfall-runoff, wastewater, potable water or indirect reuse water) is the transport and fate (control) of particulate matter (PM) and PM-bound constituents. This current consideration has a strong rationale given that urban PM is the primary source and sink for constituents including chemicals (metal elements, organics, nutrients…) and the primary habitat and vehicular substrate for pathogens. Conceptualizing permeable systems as a filtration unit operation (irrespective of unit process mechanisms) the role of PM and the coupled interaction of PM with the pore geometry has a significant impact on the driving head – flow relationship, as in clogging. However the fate of PM in any permeable systems is challenging; in part due to the hetero-disperse and variable PM size gradation that interacts with pore size distributions that can vary from mono- to hetero-disperse. Elucidating the clarification of PM in permeable systems, primarily granular filters, has led to a many empirical and semi-empirical models of PM fate over many decades under relatively constrained boundary conditions, loadings and geometries. The value and contributions of such models notwithstanding, advances in computational power and algorithms have facilitated the potential to implement more flexible, representative and powerful computational tools, in particular computational fluid dynamics (CFD). Therefore the objective of this study is to apply the principles of CFD to quantitatively demonstrate and dynamically visualize the transport and fate of PM in a permeable pavement system subject to dilute multiphase flows (< 2% PM). For many disciplines such as mechanical and chemical engineering, CFD has been used for decades, but is relative new to the field of water resources and water treatment despite the understanding that existing empirical models of transport and fate in permeable systems are less robust for complex urban water loadings. In this study a CFD model will be developed and applied to illustrate PM transport and fate in permeable systems that is otherwise difficult, at best, for existing models. In this study CFD will be applied to demonstrate the potential as a quantitative analysis and visualization tool to examine permeable systems subject to a range of pore geometries based on the existing literature. One unique aspect of what is proposed is the coupling of the continuous and discrete phases in CFD to resolve the transport and fate of particles across the entire particle size distribution (PSD). The deliverable from this research will be a final report including an animation of the transport and fate of PM in a permeable pavement system and a companion peer-reviewed manuscript.