(1. 华中科技大学 力学系, 武汉 430074;
2. 贵阳铝镁设计研究院, 贵阳 550004)
摘 要: 在ANSYS平台上采用有限元法和/k-ε/湍流模型求解粘性不可压缩流体三维雷诺平均的Navier-Stokes方程,计算在电磁力作用下铝电解槽液体流动。 对电解质和铝液的流场分别求解, 然后利用分层液体界面压强连续条件计算铝液表面变形。 230kA电解槽的计算结果表明电解质和铝液流动为近似水平的两个旋涡, 其中一个旋涡的中央区铝液表面上升,另一个旋涡中央区铝液表面下降。 流动速度从旋涡中心向外增加, 最大速度发生在电解槽边壁附近, 并迅速减少为零。 这种速度特性表明电解槽边壁某些部分承受较大摩擦力。计算结果与230kA电解槽在运行5个半月后的实测数据基本一致。
关键字: 铝电解槽; 磁流体力学; 有限元法
(1.Department of Mechanics, Huazhong University of Science & Technology, Wuhan 430074, China;
2. Guiyang Aluminum-Magnesium Design and Research Institute,
Guiyang 550004, China)
Abstract:Using finite element method and k-ε turbulence model, liquid flows and surface distortion of aluminum liquid in a reduction cell are calculated based on three-dimensional Reynolds averaged Navier-Stokes equation. The calculation is carried out on ANSYS platform. In general, the vertical flow on interface of two liquid layers is much weaker than the horizontal flows drived by electro-magnetic forces. Flow fields of molten electrolyte and aluminum liquid are solved separately. The surface distortion of aluminum liquid is calculated from the pressure difference on the liquid interface based on pressure continuous condition. Numerical example of 230kA reduction cell is presented. The numerical results indicate that the horizontal flows approximately consist of two vortices. The surface rises up in central area of one vortex, the surface sets down in central area of another vortex. The flow velocity increases outwards from vortex center. The flow velocity reaches maximum at close to cell wall and rapidly decreases to zero. The order of magnitude of flow velocity computed and the interface distortion profile computed are in agreement with measured data of 230kA reduction cell that has been operated for five months.
Key words: aluminum reduction cell; magneto-hydrodynamics; FEM