Abstract Toroidal flow was used to control the shape of the solid-liquid interface, while growing NaNO3 crystals in vertical Bridgman configuration. The flow was driven by a disk-shaped rotating Submerged Heater/baffle (SH). The flow in the inner melt, below the rotating SH/baffle, closely resembles the flow in Czochralski melts. The experiments were conducted in a transparent furnace which allowed side view to the solid-liquid interface. Without baffle rotation, interface was concave. For zero growth rate, convex interface was obtained typically at 15 rpm. The degree of convexity increased with rotation rate. While growing NaNO3 at 3.5 mm/h and 5.5 mm/h, convex interface was maintained at 45 rpm. Detailed 3D CFD numerical simulations are in solid agreement with the NaNO3 experiments. The rotating baffle process is particularly useful for growing crystals of low thermal conductivity because flow, generated by baffle rotation, carries heat radially out bypassing slow conduction through the crystal.

中文翻译：

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通过在垂直 Bridgman 配置中旋转浸入式加热器/挡板来控制界面

摘要 环形流用于控制固液界面的形状，同时以垂直布里奇曼构型生长 NaNO3 晶体。流动由盘形旋转浸没式加热器/挡板 (SH) 驱动。在旋转 SH/挡板下方的内部熔体中的流动与 Czochralski 熔体中的流动非常相似。实验是在一个透明的炉子中进行的，该炉子可以从侧面看到固液界面。无挡板旋转，界面呈凹形。对于零增长率，凸界面通常在 15 rpm 下获得。凸度随着旋转速度的增加而增加。在以 3.5 mm/h 和 5.5 mm/h 生长 NaNO3 的同时，凸面界面保持在 45 rpm。详细的 3D CFD 数值模拟与 NaNO3 实验完全一致。