Competing and coexisting dynamical states of travelling-wave convection in an annulus

Abstract

We describe experiments on convection in binary fluid mixtures in a large-aspect-ratio annular container. In this geometry, the convective rolls align radially and travel azimuthally, providing a model of travelling waves in an extended one-dimensional nonlinear dynamical system. Several different stable non-equilibrium states can be produced in this experiment, and the competition between them leads to a wide variety of steady and time-dependent behaviour. The observed spatiotemporal behaviour may shed light on recent theories of the nature of stable nonlinear travelling-wave convection, the pinning of travelling waves, and the creation of spatiotemporal defects.