旋转喷吹除气箱中气液两相流动行为的数值研究

Numerical Study on Gas-liquid Flow Behavior in Rotating Spray Degassing Tank

利用欧拉模型和多参考坐标系法对旋转喷吹除气箱中的气液两相流场进行数值模拟,提出基于计算域的选取获取自由液面波动的建模方法,并考察了不同因素对除气箱内气液两相流动行为产生的影响。结果表明,提出的获取自由液面波动的建模方法是可行的。随气泡直径的减小、搅拌转速的增加,气体在除气箱中停留时间延长,与铝熔体接触面积增大,气体在除气箱中的分布得到改善,有利于铝熔体的净化。此外,采用圆柱形除气箱,气体大多聚集在转杆周围,且易发生打漩现象,这对铝熔体的除氢不利。

The Eulerian two-fluid model incorporating with the multiple reference frame method was adopted to simulate the gas-liquid flow field in rotating spray degassing tank,and a new modeling method based on the computational domain was proposed to describe the liquid top surface.The influences of factors on the gas-liquid flow behavior were also investigated.The results show that the modeling method for describing the liquid top surface is feasible.With the decrease of bubble size and the increase of rotational speed,the purging time and melt/bubble interface increase,and purge gas distribution in degassing tank improves,which are beneficial to the refinement of melt.In addition,using the cylindrical tank,the purge gas mainly congregates around the rotational shaft,and swirl always occurs,which is disadvantage to the degassing of hydrogen.