SMS scnews item created by Lachlan Smith at Fri 4 Oct 2019 1653
Type: Seminar
Distribution: World
Expiry: 29 Nov 2019
Calendar1: 11 Oct 2019 1600
CalLoc1: Carslaw 275
Auth: lachlans@plachlans.pc (assumed)

Sydney Dynamics Group: Xin -- Enhanced Diffusivity in Chaotic Flows

Dear All, 

Next week, Friday 11th October, Jack Xin (UC Irvine) will give a talk at USyd
in Carslaw 275 at 4pm on 

Title: Enhanced Diffusivity in Chaotic Flows 

Transport phenomena in fluid flows are observed ubiquitously in nature such as smoke
rings in the air, pollutants in the aquifers, plankton blooms in the ocean, and stirring
drops of cream in a cup of coffee.  We begin with examples of two dimensional
Hamiltonian systems modelling incompressible planar flows, and illustrate the transition
from ordered to chaotic flows as the Hamiltonian function becomes more time dependent.
We introduce effective diffusivity via Lagrangian and Eulerian formulation, and show how
its enhancement relate to the existence of periodic orbits (order) and chaotic behavior
of flow trajectories (disorder).  Then we discuss enhanced diffusivity in three
dimensional chaotic flows, viz., the Arnold-Beltrami-Childress flow and the Kolmogorov
flow, through structure-preserving schemes.  

Hope to see you all there,