(4b) Single and Multiphase Flows in Well-Defined Periodic 3D-Printed Lattices

Additive manufacturing affords precise control over geometries with high degrees of complexity, such as lattices, a class of additive-only metamaterials which have great potential in directing transport phenomena. Realizing applications that leverage aerosol transport through novel lattice materials requires new analytical approaches to predict particle-laden flows through these intricate structures. Compared to a fibrous filter, lattices can achieve length scales that are orders of magnitude larger than most porous media, presenting a challenge to translate existing theoretical frameworks to fully capture the relevant transport phenomena. Conversely, the well-controlled structure of a lattice can be considered a distinct advantage, allowing us to address aerosol physics at representative groupings of unit cells that will enable scaling to the entire part. Advancing fundamental aerosol transport behavior in these newly invented metamaterials has broad implications for a wide range of engineering applications, including separations, filtration, functional coatings, heat transfer, and process intensification. However, our group is specifically motivated to evaluate aerosol-lattice dynamics so that we can integrate them within a working model of the human airway using meaningful physical approximations of airway filtration using the tunable spatial collection afforded by lattice materials. Using both experimental and computational multiphase tools, our group studies single and multiphase transport phenomena within 3D-printed lattices of well-defined structures, ranging from uniform, repeating unit cells, to patterned and directional lattice structures. Measurements of bulk transport through well-defined lattice monoliths is then investigated with computational flow profiles generated in dilute-phase simulations. From these studies, we are able to leverage distinct lattice structures to tune aerosol filtration and spatial deposition, even with lattice monoliths of comparable overall porosity. Using these basic design rules, lattices of different structures were integrated into a model of the human lung, where correctly identified lattices were able to provide deposition profiles aligning with clinical benchmarks. Overall, this work represents an important step forward in building predictive models of aerosol dynamics within well-defined lattice structures for a range of transport applications.