Abstract: Numerical simulations of fluid flow and heat transfer within the magnet of the SUNIST-2 spherical tokamak was conducted with the Fluent, and the design of water-cooling structure of the magnet was optimized. Based on the SUNIST-2 specific operational conditions, the simulation analyses of the magnet's water-cooling system performance are performed under various flow rates and different inlet temperatures, for comparing the cooling efficiency and pressure drop under each condition. The results indicate that the optimized magnet water-cooling structure scheme significantly enhances the stability and safety of the magnet under actual operational conditions, which was validated through pressure drop tests on the water-cooling structure of the fabricated magnet. 

Key words: Spherical tokamak, Magnet water cooling, Fluent, Numerical simulation, Pressure drop test

摘要： 应用 Fluent 软件对 SUNIST-2 球形托卡马克磁体内部流动与传热进行了数值模拟，对磁体的水冷结构设计进行了优化。依据 SUNIST-2 特定的工作状态，分别对磁体水冷系统在多种流速及不同进口温度条件下的性能进行了仿真分析， 对比了各条件下的冷却效能与压力降。模拟研究表明，基于数值模拟优化的磁体水冷结构方案，显著增强了磁体在实际运行状态下的稳定性与安全性。加工后的磁体水冷结构的压力降测试的实验结果验证了数值模拟的结论。 

关键词: 球形托卡马克装置, 磁体水冷, Fluent, 数值模拟, 压降测试