Experimental study of cylinder wakes in electrolytes under axial magnetic field

在磁场的影响下，导电流体的流动发生在各种各样的情况下，从地球核心中的液态铁的流动到材料加工中的熔融钢、铝或钛的运动。由于液态金属是不透明的，其内部无法可视化，这严重阻碍了我们对磁流体动力学（MHD）流动的理解。本项目的目的是证明，由于伊尔梅瑙理工大学的超导5特斯拉磁体，实验MHD的这一基本限制可以克服。该设备使我们能够用透明的电解质代替不透明的液态金属进行磁流体动力学实验。实验计划将涉及设计，建造和开发一个紧凑的电解质通道，其中磁流体绕圆柱形障碍物的流动将进行研究。实验过程将涉及使用示踪粒子和染料的速度可视化以及使用激光多普勒测速仪和电势测速仪的速度测量，雷诺数在30 < Re < 900范围内变化，哈特曼数在0 < Ha < 30范围内变化。这是第一次实验将提供一个直接的光学访问磁流体柱以上的圆柱体，以前从来没有直接观察到。该信息对于磁场的各种工业应用包括夹杂物分离和磁制动是潜在有用的。

Flows of electrically conducting fluids under the influence of a magnetic field occur under a wide range of circumstances ranging from the flow of liquid iron in the Earth s core to the movement of molten steel, aluminium or titanium in materials processing. Since liquid metals are opaque, their interior cannot be visualized, which severely hampers our understanding of magneto hydrodynamic (MHD) flows. The purpose of the present project is to demonstrate that this fundamental limitation of experimental MHD can be overcome thanks to a superconducting 5-Tesla magnet at Ilmenau University of Technology. This facility permits us to perform MHD experiments with transparent electrolytes instead of opaque liquid metals. The experimental program will involve design, construction and exploitation of a compact electrolyte channel in which the MHD-flow around a cylindrical obstacle will be studied. The experimental procedure will involve velocity visualizations using tracer particles and dye as well as velocity measurements using laser Doppler velocimetry and electric potential velocimetry for variable Reynolds number in the range 30 < Re < 900 and with variable Hartmann numbers in the range 0 < Ha < 30. For the first time the experiments will provide a direct optical access to MHD-columns above the cylinders which have never before been directly observed. This information is potentially useful for a variety of industrial applications of magnetic fields including separation of inclusions and magnetic braking.