Dynamics of two-dimensional traveling-wave convection patterns.

We report an experimental study of traveling-wave convection patterns in a binary mixture of ethanol and water. We survey the patterns observed in a large aspect ratio cylindrical container over a broad range of Rayleigh numbers. It is found that disordered patterns observed immediately after travelingwave convection is initiated evolve toward organized multi-domain patterns, and that the nature of the multi-domain patterns depends on the Rayleigh number. A novel numerical algorithm for extracting the complex order parameter from traveling-wave patterns and measuring their dynamical properties is described. This technique is used to characterize the dynamic aspects of traveling-wave convection patterns observed near the saddle node bifurcation. It is shown that the instantaneous rate of deformation of the pattern can be determined, and use of this information as a point of comparison with model equations is discussed. The joint wavenumber-frequency distribution for traveling-wave patterns is calculated, and is shown to be signi cantly di erent from the dispersion curves previously obtained from one-dimensional traveling-wave convection patterns. PACS numbers: 47.54+r, 47.55Hd, 47.27Te