Temperature Oscillation of Marangoni Flow in Molten Silicon Column

Abstract

Marangoni convection in molten silicon was studied from the viewpoint of a heat and mass transfer for a low Prandtl number liquid. Using the NASDA rocket TR-IA #4, the temperature oscillation in molten silicon having a column shape was precisely measured in microgravity conditions. Fourier-transformation analysis showed oscillation with a particular frequency of 0.1 Hz while the column was forming and non-periodic oscillation after it had formed . The appearance of a non­periodic-oscillatory flow mode would be supported by a high Marangoni number, such as 30,000 calculated from a recently reported temperature coefficient of surface tension for molten silicon.