Non-condensable gas influence on the Marangoni convection during a single vapour bubble growth in a subcooled liquidM. Barthes, C. Reynard, R. Santini and L. Tadrist
Laboratoire IUSTI CNRS UMR 6595 - 5 Rue Enrico Fermi, technopôle de Château-Gombert, 13453 Marseille Cedex 13, France
received 12 April 2006; accepted in final form 9 November 2006; published January 2007
published online 12 January 2007
Liquid convective instabilities during a single vapour bubble growth in subcooled FC-72 are experimentally investigated. The bubble was created on an artificial nucleation site located on a downward-facing heating element. For a non-degassed liquid, convective instabilities were observed using a shadowgraphy method and tracer particles. Both stationary and oscillatory modes were observed, and this instability was found to be Marangoni convection. Comparing results with a degassed and a non-degassed liquid, it was found that the onset of Marangoni convection was due to the presence of non-condensable gases in the liquid. Finally, the combination of Marangoni convection and condensation enables us to highlight a thermal oscillator, with a change in the type of oscillatory motion during the condensation phase.
47.55.dp - Cavitation and boiling .
47.55.pf - Marangoni convection .
47.55.dm - Thermocapillary effects .
© Europhysics Letters Association 2007