磁场和自由界面热流下二维液态锡膜流的传热模拟

2D numerical simulations of liquid tin film flows with heat flux on free surface under a perpendicular magnetic field

液态金属偏滤器具有自修复和热负荷能力,因此成为偏滤器的重要设计方案。偏滤器上的液态金属膜流处于磁场和高强度热流下,且装置运行时产生的低频扰动会使薄膜流动发展为毛细孤立波。在毛细孤立波膜流中,波谷位置的毛细分离涡会显著增强该区域的对流换热。研究雷诺数为58的液态锡毛细孤立波膜流在底壁附近的换热现象。结果表明:无外加磁场和自由界面热流时,液态锡毛细孤立波薄膜流动复现了努塞尔数在波谷位置显著增强的现象;仅施加磁场时,由于洛伦兹力的阻尼效应,毛细分离涡处的换热增强效果被抑制;仅施加热流时,由于膜流被加热,总换热量增加,导致努塞尔数分布更均匀;同时施加磁场和热流时,两者的作用会叠加。

With capacities of self-cleaning and sustaining high heat load,liquid-metal divertor is one important design of first wall component.Liquid-metal divertor has to be faced with external magnetic fields and high-intensity heat flux,and in devices,existence of low-frequency disturbances is inevitable,which would make liquid-metal film flows develop into capillary solitary waves,in which capillary separation eddies at wave troughs would strengthen heat convection there.In this research,heat transportation of liquid-tin film flows with capillary solitary waves is studied under Re=58.When there is no magnetic field and free-surface heat flux,capillary solitary waves of liquid tin have same features of water waves and Nu number also reaches peak at wave trough.When only magnetic field is exerted,Lorentz force has damping effects on waves and accordingly,the enhancement of heat transfer from capillary separation eddies decreases.When only free-surface heat flux is exerted,film flows are heated and distribution of Nu number become more uniform.When both magnetic field and heat flux are exerted,their effects will be stacked.