NUMERICAL INVESTIGATION OF SILICON MELT FLOW IN A SHALLOW ANNULAR POOL UNDER AN AXIAL MAGNETIC FIELD

Abstract

In order to understand the effect of the magnetic field on surface patterns on semi-conducting silicon melt in industrial Czochralski furnaces, we conducted a series of unsteady three-dimensional numerical simulations of silicon melt flow in a shallow annular pool under the axial magnetic field for the magnetic field strength from 0 to 0.1T. The pool is heated from the outer cylindrical wall and cooled at the inner wall. Bottom and top surfaces are adiabatic. When the magnetic field is weak, the simulation can predict various three-dimensional oscillatory flows depending on the radial temperature difference. With the much larger magnetic field, three-dimensional flow becomes axisymmetric steady flow. Details of flow and temperature disturbances are discussed and the critical magnetic field strengths for the onset of axisymmetric steady flow are determined.