Open Access

ARTICLE

Thermocapillary Flow and Phase Change in Some Widespread Materials Processes

by Gustav Amberg¹, Junichiro Shiomi²

1 KTH Mechanics, S-100 44 Stockholm, Sweden, gustava@mech.kth.se
2 Department of Mechanical Engineering, The University of Tokyo7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan

Fluid Dynamics & Materials Processing 2005, 1(1), 81-96. https://doi.org/10.3970/fdmp.2005.001.081

Abstract

A few issues in materials science are reviewed with regard to the importance of fluid flows. The effect of convection on generic solidification problems is discussed. One relevant class of flows in melts is those driven by surface tension gradients. In welding this thermo- or solutocapillary flow will determine the penetration depth, and will depend very sensitively on the composition of the material, through the dependence of surface tension on temperature, presence of surfactants, etc. In crystal growth the convective motion in the melt may cause instabilities that are often undesired in practical processes. The unsteady flow structure can cause inhomogeneous chemical composition at the solidification interface. Work has recently been done to apply active feedback control to suppress the thermocapillary oscillation. In the high Prandtl limit, a significant attenuation can be obtained by means of rather simple control methods.

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Keywords

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