DYNAMICS OF 2-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 obser ved in a large aspect ratio cylindrical container over a broad range o f Rayleigh numbers. It is found that disordered patterns observed imme diately after traveling-wave convection is initiated evolve toward org anized multidomain patterns and that the nature of the multidomain pat terns depends on the Rayleigh number. A numerical algorithm for extrac ting the complex order parameter from traveling-wave patterns and meas uring their dynamical properties is described. This technique is used to characterize the dynamic aspects of traveling-wave convection patte rns observed near the saddle node bifurcation. It is shown that the in stantaneous 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 wave number, frequency distribution for travel ing-wave patterns is calculated and is shown to be significantly diffe rent from the dispersion curves previously obtained from one-dimension al traveling-wave convection patterns.