Different convection dynamics in mixtures with the same separation ratio
Kristina Lerman, Guenter Ahlers and David S. Cannell
Department of Physics and Center for Nonlinear Science
University of California at Santa Barbara
Santa Barbara, CA 93106.
September 8, 1995
Abstract
We report a study of convection in circular geometry using ethanol-water
mixtures with two very different ethanol concentrations, but with the
same
negative separation ratio. The two mixtures show very different convective
be-
havior. In the high concentration mixture, convection begins with a
sequence
of transients that always results in a cell filling state. In the low
concentration
mixture, there is a range of control parameter where a novel "wall"
state is
the apparently stable state. In other runs at the same value of the
control
parameter, repeated transients and aperiodically fluctuating localized
regions
of disordered convection persist for days.
(Full paper)