Hydrothermal waves in a disk of fluid

Rayleigh-Bénard and Bénard-Marangoni instabilities have been studied for roughly a century and have served as prototypes for the transition to temporal chaos as well as spatiotemporal chaos of an initially stationary pattern. Using the Marangoni effect [1,2] with an horizontal temperature gradient to drive the system out of equilibrium, one can observe propagating waves instabilities: hydrothermal waves [3]. This paper presents different instability regimes of thermocapillary flows in extended geometry, focusing on propagating waves. We first introduce thermocapillary flows, and give some indications about physical effects involved. We then review experimental results in cylindrical geometry and illustrate how rich those systems are.