%0 Journal Article %T Origin of waves in surface-tension-driven convection %+ Universidad de Navarra [Pamplona] (UNAV) %+ Service de physique de l'état condensé (SPEC - UMR3680) %+ Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes (SPHYNX) %A Garcimartí, Angel %A Mukolobwiez, Nathalie %A Daviaud, François %Z Financial support from the European Union (Contract No. ERBCHRXT940546), from the Spanish Government (Contract No. PB95-0578), from the University of Navarre (PIUNA), and from Integrated French-Spanish Action Picasso No. 93024 %< avec comité de lecture %@ 2470-0045 %J Physical Review E %I American Physical Society (APS) %V 56 %P 1699-1705 %8 1997 %D 1997 %Z PACS numbers : 47.20.Dr, 47.20.Bp, 47.27.2i %Z Physics [physics]Journal articles %X 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. %G English %2 https://cea.hal.science/cea-01373964/document %2 https://cea.hal.science/cea-01373964/file/1997.PRE56.pdf %L cea-01373964 %U https://cea.hal.science/cea-01373964 %~ CEA %~ CNRS %~ IRAMIS-SPEC %~ IRAMIS %~ GS-PHYSIQUE