Observation and calculation of Marangoni convection induced thermally in a molten salt

AbstractMarangoni convection has a large effect on materials processing since it remarkably enhances heat and mass transport near a free interface. To have a better understanding of the behavior of Marangoni convection in molten salts, observation and calculation of the thermal convection in a column held between a pair of Pt disks (2 mm in diameter) fixed to hot thermocouples, were carried out.Calculated flow patterns and absolute values of fluid velocity agreed well with the observed results. When the temperatures of both disks were set equal and the height of liquid column was 2.4 mm, four vortices were generated on the longitudinal plane with a typical velocity of 15 mm/s. From the calculated isothermal lines, the behavior of the enhanced heat transport was obvious; fluid heated at the disks was conveyed to the free surface and the cooled fluid at the surface was conveyed to the inner region. © 1998 Canadian Institute of Mining and Metallurgy. Published by Elsevier Science Ltd. All rights reserved. Re...