Université Paris-Saclay (Bâtiment Bréguet, 3 Rue Joliot Curie 2e ét, 91190 Gif-sur-Yvette - France)
Abstract : Waves appear in a liquid layer with a free surface if a sufficiently high horizontal temperature gradient is imposed. These waves have been compared to the hydrothermal waves predicted by a linear stability analysis of a parallel flow. However, depending on the experimental configurations, significant differences with theory are found. We show that there exists another kind of wave that cannot be explained by previous analysis. Our aim is to investigate which is the mechanism leading to this instability. Differential interferometry is used to obtain quantitative information on the temperature field. Experimental evidence is presented suggesting that these waves are the result of a boundary layer instability: the roll near the hot wall begins to oscillate, and the perturbations are dragged and amplified downflow. This mechanism could explain discrepancies between theory and some experimental observations.
https://hal-cea.archives-ouvertes.fr/cea-01373964 Contributor : Dominique GIRARDConnect in order to contact the contributor Submitted on : Thursday, September 29, 2016 - 2:38:41 PM Last modification on : Monday, December 13, 2021 - 9:16:32 AM Long-term archiving on: : Friday, December 30, 2016 - 2:01:27 PM
Angel Garcimartí, Nathalie Mukolobwiez, François Daviaud. Origin of waves in surface-tension-driven convection. Physical Review E , American Physical Society (APS), 1997, 56, pp.1699-1705. ⟨cea-01373964⟩