Dynamics of a wetting layer and Marangoni convection in microgravity - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Physical Review E : Statistical, Nonlinear, and Soft Matter Physics Année : 2011

Dynamics of a wetting layer and Marangoni convection in microgravity

Résumé

Near the liquid-vapor critical point in pure fluids, material and thermal properties vary considerably with temperature. In a series of microgravity experiments, sulfur hexafluoride (SF6) was heated ∼1 K above its critical temperature, then quenched below the critical temperature in order to form gas and liquid domains. We found a power law exponent of 0.389 ± 0.010 for the growth of the wetting layer thickness during the intermediate stage of phase separation. Full and microscopic view images of the sample cell unit were analyzed to determine the changes in the size distribution of liquid droplets inside the gas phase over time. We found that the distribution of diameters for liquid droplets always contains a fraction of very small droplets, presumably due to a continuous nucleation process. At the same time, the size distribution flattens over time and rapidly includes large-size droplets, presumably generated through a coalescence mechanism. By following both a large gas bubble over two hours of video recordings, we found periodic and synchronous motion of the gas bubble along both the x and y directions. By following a large liquid droplet embedded into the large gas bubble, we found periodic, out of phase motions, which we related to Marangoni convection. The experimentally measured velocity of the liquid droplet is in good agreement with the theoretical predicted velocity of ∼0.386 μm/s obtained from Young's thermocapillary effect.
Fichier principal
Vignette du fichier
OprisanA_PhysRevE_2011.pdf (918.3 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-00617186 , version 1 (30-08-2023)

Identifiants

Citer

Ana Oprisan, John Hegseth, Gregory M. Smith, Carole Lecoutre-Chabot, Yves Garrabos, et al.. Dynamics of a wetting layer and Marangoni convection in microgravity. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2011, 84 (2), pp.021202. ⟨10.1103/PhysRevE.84.021202⟩. ⟨hal-00617186⟩
149 Consultations
13 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More