Speaker:

Laurette Tuckerman, University of Pierre and Marie Curie

Title:

Patterns in Turbulence

Abstract:

The greatest mystery in fluid dynamics, and perhaps in all of physics,
is transition to turbulence.  The simplest shear flow, plane Couette
flow -- the flow between parallel plates moving at different
velocities -- is linearly stable for all Reynolds numbers
(nondimensionalized velocity gradients), but nevertheless undergoes
sudden transition to 3D turbulence at Reynolds numbers near 325.  At
precisely these Reynolds numbers, it was recently discovered
experimentally that there appears a steady and regular pattern of
alternating wide turbulent and laminar bands, tilted at an angle with
respect to the direction of motion of the bounding plates.  We report
on numerical simulations of this remarkable flow.