水平磁场中液态金属射流的三维数值研究

3D numercial simulations of liquid metal jet under a horizontal magnetic field

磁场中液态金属射流的流动行为研究对聚变装置强磁场环境下液态金属第一壁的实现极为重要。对处于横向水平磁场中的液态金属竖直射流进行三维的直接数值模拟,主要对小We数情形射流在不同磁场强度下的破碎行为进行研究。模拟发现,在磁流体动力学效应下,液态金属射流的稳定性得到明显的增强,其破碎长度随着磁场强度的增大而增长。同时,液态金属射流在磁场中破碎后形成的液滴随着磁场强度的增大而逐渐减小。磁场强度越大,洛伦兹力使射流界面扰动波的波长变得越长。对于较大We数情形,磁场对射流的界面扰动影响更为明显。射流界面处的膨胀波及正弦波扰动由三维变为明显的二维状态,射流的稳定性也因此明显增强。

The liquid metal jet under a horizontal magnetic field plays a significant role in the fusion reactor.3D numerical simulations of the liquid jet under a horizontal magnetic field are performed in this study,and we mainly study the breakup of the liquid jet at the low Weber numbers under different magnetic fields.The stability of the liquid metal jet changes in the magnetic field.The breakup length of the liquid metal jet grows with the increase of magnetic field.Meanwhile,the droplets form when the liquid metal jet breaks up.The volume of the droplet decreases with the increase of magnetic field.As the magnetic field increases,the wavelength of the interfacial disturbance wave increases due to the Lorentz force.In the case of a large Weber number,the magnetic field exerts a great influence on the interfacial disturbance.At the surface of the liquid metal jet,the 3D dilatational wave and sinuous wave become the 2D ones under the vertical magnetic field.Therefore,the stability of the liquid metal jet is significantly enhanced.