Open Access

ARTICLE

Convective Instability in Annular Pools

by

1 Chongqing University, Chongqing, China
2 Kyushu University, Kasuga, Japan

Fluid Dynamics & Materials Processing 2006, 2(3), 153-166. https://doi.org/10.3970/fdmp.2006.002.153

Abstract

The convective instabilities in semiconduc-tor or oxide melts, significantly affect the quality oflarge crystals grown from the melts by the Czochralskimethod. This paper reviewsour recent numerical stud-ies of thermal convection in annular pools of low-Pr sili-con melt and moderate-Pr silicone oil. The mechanismsof the convective instability are discussed and the criticalconditions for the onset of three-dimensional flow are de-termined. The results show that the hydrothermal wave,characterized by curved spokes, is dominant in a shallowthin pool. In a thick pool of the low-Pr silicon melt, thereappears a standing wave type of oscillatory longitudinalrolls, which moves in the azimuthal direction and looksvery similar to the hydrothermal waves. In deep poolsof moderate-Pr silicone oil, a three-dimensional steadyflow pattern, consistingof pairs of counter-rotating longi-tudinal rolls, arises, which corresponds to the Rayleigh-Benard instability

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Keywords

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