Motion of a particle in a solution containing thick and thin regions

When a group of particles is released in a fluid, they will disperse throughout the solution via diffusion. If we consider a solution that is thick (like honey) in some regions and thin (like water) in others, where will the particles end up? Will they become trapped in the honey, concentrated in the water where they move freely, or evenly distributed throughout? It turns out the answer depends on the details of how the interface between the thick and thin regions are treated. In this project, simulation and numerical techniques will be employed to investigate the diffusion of particles in 2D systems containing regions of different viscosities. The relative concentrations and effective diffusion coefficients of particles in patchy (random viscous inclusions of various sizes) or ordered (eg., stripes alternating thick and thin) arrangements will be studied. Results will be generated for several treatments of the interfaces. Considering application to the release of drugs within biological systems or the dispersion of particulate matter in food preparation and aging, which approach is most physical? What do these results tell us about the efficiency of delivering drugs or mixing substances? Can we design configurations to control the mixing or even separate particles based on their size?

Faculty Supervisor:

Gary W. Slater

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University of Ottawa

Program:

Globalink Research Internship