非对称勾形磁场的三维优化设计与实现

根据坩埚内熔体对流的类型和分布区域,分析控制对流对勾形(cusp)磁场磁感应强度和磁场位形分布的要求,提出了磁场优化设计目标。采用有限元三维(3D)建模法对cusp磁场进行了建模,利用所建立的模型对比了对称结构和非对称结构对磁场位形分布的影响,分析了在非对称cusp磁场线圈横向层数一定的情况下磁场纵向层数、屏蔽体厚度、上下线圈间距对磁感应强度、磁场位形、磁场功率的影响,优化了磁场结构;根据优化的结构参数制造了磁场并进行了实验测试,结果表明非对称cusp磁场的位形分布与设计结果一致,从而验证了3D优化建模方法的有效性。

3D Optimization Design and Realization of the Asymmetric Cusp Magnetic Field

In this paper,the requirements of the intensity and distribution of cusp magnetic flux density to control the convection are analyzed according to the type and distribution area of this convection in crucible,on the basis of which the optimization design goal is proposed.The simulation model of cusp magnetic field is built by the finite element with three dimension(3D) modeling method.The established model is used to contrast the effect of symmetrical structure and asymmetric structure upon the magnetic field shape distribution and also to analyze the magnetic field longitudinal layers,shield body thickness and the effect of up-and-down coil distance upon magnetic flux density,magnetic field shape and magnetic field power in the case of the fixed horizontal layers of asymmetric cusp magnetic field coils,so as to optimize magnetic field structure.Magnetic field is generated in terms of optimized structure parameters,and also,the experimental test is conducted.The results indicate that asymmetric cusp magnetic field shape distribution is found to be in coincidence with the designed results whereby testing that 3D optimal modeling method is of validity.