TRANSIENT LOCALIZED STATES IN 2D BINARY-LIQUID CONVECTION

We report an experimental study of the onset of convection in ethanol/water mixtures confined in a circular cell of radial aspect ratio of 11.6. The initial bifurcation was to radial traveling waves; however, the linear state typically gave way to a nonlinear one in which convection alternately focused along one cell diameter and then another roughly perpendicular to the first. After a number of cycles, this state frequently contracted radially to a localized pulse of traveling-wave convection very similar to those observed in 1 D geometries. The pulses we observed either decayed back to pure conduction or grew to fill or nearly fill the cell.