Experimental study on the free surface defor-mation in the oxide melt

Abstract

Experiments on the thermocapillary convection of high temperature Bi12SiO20 melts have been carried out in the in situ observation system. The steady flow pattern comprises of the main trunk and branches, which is deemed as the surface deformation. The oscillatory thermocapillary convection is characterized by the oscillatory main trunk and traveling branches. The transition of the melt from steady spatial to oscillatory behavior under the temperature differences 120, 60 and 10 K has been considered. The free surface deformation is observed to transform with the change of the applied temperature difference, which manifests that the thermocapillary convection is sensitive to the temperature difference. Moreover, taking the temperature distribution into account, it is noted that the deformation is formed in the colder area of the melt. The oscillatory frequency of the main trunk, which is also sensitive to the applied temperature difference, increases with the rise of temperature.