网格大小对RH精炼大涡模拟正确性的影响

Effect of large eddy simulation on fluid flow of RH degassing process

RH真空处理具有脱气、脱碳、去夹杂等冶金功能,在生产IF钢、硅钢等低碳、超低碳钢中有广泛的应用。为了实现对冶金反应器内部现象的研究,常用方法有物理模拟或数值模拟。通过模拟的方法对RH内部流体流动进行研究,具有易于实现、可控性高等优点。采用大涡模拟的方法对RH真空循环精炼过程中的多相流体流动进行模拟,得到了整个循环精炼过程中整个区域内的瞬态速度分布,同时获得了湍流涡的产生和耗散过程。进一步考虑了不同网格数量对计算结果的影响,表明在速度值较大的区域,由于网格差异引入的误差也较大。因此,选择合适的网格对于采用大涡模拟来实现对湍流模拟的方法至关重要。

The RH degassing process was widely used in the production the low carbon steel and the ultra-low carbon steel,such as IF steels and silicon steels,due to its high efficiency on degassing,decarburization and inclusions removal.To investigate the interior phenomena during the metallurgical process,various physical models and mathematical models were established to simulate the internal behavior of metallurgical reactors.Using simulation methods was easy to implement and control.A 3 D mathematical model was established to investigate the multiphase fluid flow in the RH refining process.The transient velocity distribution and the generation and the dissipation of the vortexes of the whole fluid domain were obtained.Further,the effect of the mesh on the fluid flow was studied by comparing the results calculated by four different meshes.The comparison showed that the deviation of the region with a larger local velocity introduced by mesh difference was larger than the deviation of that with a smaller local velocity.Thus,the selection of the suitable mesh was vital to the LES model to simulate the fluid flow accurately.