Three-dimensional unsteady thermocapillary flow under rotating magnetic field

Liping Yao, Zhong Zeng, Yi Zhang, Zhouhua Qiu, Hiroshi Mizuseki, Yoshiyuki Kawazoe

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Under a rotating magnetic filed (RMF), the instability of thermocapillary flow and its evolution with increasing Marangoni number (Ma) for semiconductor melt (Pr = 0.01) in a floating liquid bridge model (As = 1) are investigated numerically. Under 5 mT RMF, the thermocapillary flow is steady and axisymmetric with Ma < Ma c, and the critical Marangoni number Ma c for convection instability is 29.5, which is obtained by the direct numerical simulation. When the Ma is a little bit beyond the Ma c, the thermocapillary flow loses stability to become a three-dimensional rotating oscillatory convection, and a periodic oscillation is confirmed by the fast Fourier transform analysis, the oscillatory main frequency decays with increasing Ma. Under 1 mT-6 mT RMF, the Ma c increases roughly with the magnetic strength except the Ma c at 4 mT, where the corresponding change of flow mode after the instability is observed. The oscillatory convection occurs with a smaller Ma in the RMF than that without magnetic field. In addition, no instability toward a three-dimensional steady convection, which is the state of thermocapillary flow without magnetic field after the first instability, is observed under the RMF.

Original languageEnglish
Pages (from-to)816-823
Number of pages8
JournalCrystal Research and Technology
Volume47
Issue number8
DOIs
Publication statusPublished - 2012 Aug 1

Keywords

  • float-zone
  • microgravity
  • rotating magnetic field
  • thermocapillary flow

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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