Blinking
rolls: Chaotic Advection in a 3D Flow with an Invariant
Paul Mullowney, Keith Julien and James Meiss
University of Colorado
Chaotic
advection of passive scalars can act as an efficient mixing method even when
the underlying flow is not turbulent. Here, we discuss a 3D analog of the 2D
blinking vortex model of Aref that exhibits complex and chaotic behavior. The fluid motion consists of
alternately active 2D rolls acting in
different planes. For our system, as in Aref's case, exact solutions of the particle trajectories can be used to explicitly construct a mapping for the
system. We will show that when the rolls are orthogonal there is an invariant
that prevents full mixing, though
two-dimensional mixing occurs. We vary the parameters of the system and study the efficiency of the
resulting mixing.