Shape Optimization of Magnetic Core of Electromagnetic Stirrer for Melted Silicon

Volume heating used during silicon purifying permit uniformly temperature distribution at all bowl. Forced stirring with quartz devices is associated with high process failure and low efficiency. To intensify the process, it is proposed to use electromagnetic stirring by a traveling magnetic field. Optimal shape design of stirrer can be obtained by a multiobjective optimization method based on gradient descent to reduce primary weight and stirring time, simultaneously. Objective function is defined from magnetohydrodynamic problem considered in this article. Also, different version of magnetic core is examined. This coupled-field problem is decoupled to separated magnetic, hydrodynamic and thermal problems and analyzed by means of finite element method, while the optimal design problem is solved by gradient-based algorithm and best solution is chosen.