Rayleigh-Benard Convection In Wine

Rayleigh-Benard convection is the flow fluid induced by thermal expansion in a thin horizontal layer of fluid which is heated from below. This experiment is almost a century old. The discovery a few years ago of traveling waves of convection in binary fluid mixtures such as ethanol/water mixtures renewed interest in this field. In this system, the first instability is oscillatory, leading to intrinsic time-dependence at the onset of convection. The nonlinear evolution of this state of traveling waves can be extremely complex, leading in some instances to flows in which convection appears only in part of the experimental cell. In this talk, I will focus on recent experiments concerning linear and weakly nonlinear traveling-wave convection. In the weakly nonlinear regime, the flow consists of one-dimensional wave trains which are modulated due to the nonlinear competition between oppositely-propagating waves. Very close correspondence with recent theories has been found.