Bifurcation to chaos in the Benard-Marangoni instability in a confined geometry

An experimental study of dynamical regimes in Benard-Marangoni convection, for various Prandt and Marangoni numbers, has been carried out in a confined geometry. Indeed, a small hexagonal vessel allowing the formation of only one convective cell, for a large extent of the Marangoni number, has been used. Fourrier spectra and a correlation function have been used to recognize the various dynamical regimes. For fixed values of the Prantl number and aspect ratio, an oscillatory, a quasi-periodic and chaotic states, were successively observed, as the Marangoni number was increased. The correlation dimensions of strange attractors corresponding to the chaotic regimes were calculated. The dimensions were found to be larger then those calculated by other authors for the Rayleigh-Benard convection in small aspect ratio geometries. The transition from temporal chaos to spatio - temporal chaos has also been observed. Indeed for higher values of the Marangoni number, spatial dynamics are observed