Study of solidification in a simulated czochralski system via liquid crystal tracers

摘要

Visualization of the solidification of water from a simulated crystal seed in a Czochralski system is performed for various rotation rates of the crystal and crucible. Liquid Crystal Thermography is employed to capture images of the solidification process and the resulting flow and temperature fields. Experiments are conducted for Grashof number of approx apprx 4.5 x 10~5. Effects of convective forces on the crystal/melt interface are discussed for four rotation modes: no rotation, crystal rotation, crucible rotation and counter-rotation. A quantitative estimate of the temperature field is obtained via a suitable calibration of the liquid crystals.