Mathematics Colloquium

4:00 pm–4:50 pm
Avery Hall Room: 115
Additional Info: AVH
Steve Cohn, 402-472-7223, scohn1@math.unl.edu
Speaker: Ivan Christov
Affiliation: Theoretical Division & Center for Nonlinear Studies, Los Alamos National Laboratory
Local Hosts: Petronela Radu and Mikil Foss
Title: Transport phenomena in flows of granular materials

Additional Public Info:

<b>Abstract</b>: Flowing granular materials are an example of a heterogeneous complex system away from equilibrium. As a result, their dynamics are still poorly understood. One canonical example is granular flow in a slowly-rotating container. The shape of the container can induce chaotic trajectories, while the properties of the individual particles can lead to self-organization (demixing). The balance between these two effects leads to intricate persistent mixing patterns, which correspond to eigenmodes of an appropriate operator (Christov, Ottino & Lueptow, Phys. Fluids, 2011). In a variation of the previous experiment, it has been suggested that axial diffusion of granular matter in a rotating drum might be “anomalous” in the sense that the mean squared displacement of particles follows a power law in time with exponent less than unity. We can show that such a paradox can be resolved using Barenblatt’s theory of self-similar intermediate asymptotics (Christov & Stone, Proc. Natl Acad. Sci. USA, 2012). This research was supported by NSF Grant DMS-1104047.

Refeshments will be served 348 Avery 3:30-4:00.
The talk is free and open to the public.

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