Open Access. Powered by Scholars. Published by Universities.®
Statistical, Nonlinear, and Soft Matter Physics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Publication
Articles 1 - 2 of 2
Full-Text Articles in Statistical, Nonlinear, and Soft Matter Physics
Long-Range And Chaotic Active Mixing Of Swimming Microbes In A Vortex Chain Flow, Nghia Le
Long-Range And Chaotic Active Mixing Of Swimming Microbes In A Vortex Chain Flow, Nghia Le
Honors Theses
We present experiments studying the motion and active mixing of swimming mi- crobes in laminar, vortex-dominated fluid flows. We are testing a theory that predicts the existence of swimming invariant manifolds (SwIMs) - invisible, one-way barriers blocking the paths of self-propelled tracers in the flow in one direction. We also pro- pose that the SwIMs together can form chute structures in three-dimensional phase space that facilitate cross-vortex transport of the microbes. We also observe evidence of how these structures promote long-range transport at different non-dimensional velocities (microbe’s velocity relative to flow velocity). Long-range transport is quan- tified by measuring the …
Vibrated Squares As Equilibrium And Active Matter, Lee Askew Walsh
Vibrated Squares As Equilibrium And Active Matter, Lee Askew Walsh
Doctoral Dissertations
We study the effects of particle shape and self-propulsion on the collective behaviors of a two-dimensional granular fluid, using an experimental system of hard square grains. We energize the system by vibration, which, depending on particle shape, induces either isotropic diffusion or persistent self-propulsion in the particles. We use specially designed grains as a model system to study (i) the equilibrium packing of hard squares in two dimensions, (ii) the dynamics of athermal self-propelled particles, and (iii) the melting kinetics of an unconfined granular crystallite. The first study concerns the phase diagram of a two-dimensional fluid of hard squares, which …