Numerical investigation of heat and mass transfer during vertical Bridgman crystal growth under rotational vibrations

• Published in: Journal of crystal growth 2014-01, Vol.385, p.82-87
• Main Authors: Lyubimova, T.P., Parshakova, Ya.N.
• Format: Article
• Language: English
• Subjects: A1. Convection; A1. Directional solidification; B1. Alloys; Bridgman method; Crystal growth; Crystals; Ethyl alcohol; Mass transfer; Melts; Rotation; Vibration
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2013.04.063

The paper deals with the numerical investigation of convective flows and heat and mass transfer in the directional solidification of binary melts in the presence of rotational vibrations of finite amplitude and frequency. The study is performed in the framework of the Boussinesq approximation and unsteady axisymmetric approach, taking into account the existence of the two-phase zone. The simulation is conducted for binary melt with low phase change temperature (succinonitrile with ethanol), using ANSYS Fluent package which realizes the finite volume method. The data on the temporal evolution of velocity, temperature and solute concentration fields in the melt and on the solute distribution in the grown crystal with and without vibrations are obtained. It is demonstrated that the vibrations make strong stabilizing effect; they reduce the radial segregation and prevent the pit formation and solidification front breakdown, which leads to a substantial increase of grown crystal homogeneity. •Vibration effect on the directional solidification of binary alloys is studied.•The computations are performed taking into account the existence of the two-phase zone.•The instability starts with the pit formation near the axis.•Rotational vibrations prevent the pit formation and solidification front breakdown.•Rotational vibrations reduce radial segregation and improve the crystal homogeneity.