| Source | FDMP, Vol. 2, No. 3, pp. 153-166 |
| Download | Full length paper in PDF format. Size = 481,980 bytes |
| Keywords | Convection, Instability, Numerical simulation, Annular pool. |
| Abstract | The convective instability in semiconductor or oxide melts, significantly affects the quality of large crystals grown from the melts by the Czochralski method. This paper reviews our recent numerical studies of thermal convection in the annular pools of the low-Pr silicon melt and the moderate-Pr silicone oil. The mechanisms of the convective instability are certified and the critical conditions for the onset of three-dimensional flow are determined. The results show that the hydrothermal wave, characterized by the curved spokes, is dominant in a shallow thin pool. In a thick pool of the low-Pr silicon melt, there appears a standing wave type of oscillatory longitudinal rolls, which moves in the azimuthal direction and looks very similar to the hydrothermal waves. In the deep pools of the moderate-Pr silicone oil, the three-dimensional steady flow pattern, consisting of pairs of counter-rotating longitudinal rolls, appears, which corresponds to the Rayleigh-Benard instability. |