应用DLA模型模拟钢中夹杂物集团凝聚

Simulation on cluster-agglomeration of inclusions in molten steel with DLA model

为探索钢水中大量粒子的凝聚过程,应用分形理论的DLA模型,对粒子集团凝聚行为进行了模拟研究.结果表明,模拟得到的凝聚体与钢中簇状类型夹杂物的形状相似.根据分形理论可以认为它们的凝聚过程遵守同一规则.大量粒子凝聚时先是各自凝聚成小集团,然后再合并成大集团.形成相等尺寸的粒子集团所需时间不同,初始条件相同形成的粒子集团形状不同.粒子凝聚速度随其移动步长和粒子浓度增大而加快,夹杂物粒子平均移动步长主要受钢水粘度和粒子尺寸影响.粒子集团大小分布随凝聚时间和粒子平均移动步长而变化.

The cluster-agglomeration pattern was simulated with DLA model in the fractal theory to study the agglomeration process of a great number of inclusion particles in molten steel. The results show that the shapes of agglomerates are alike to the cluster type inclusion particles in molten steel. By the rule in the fractal theory the agglomeration process can be considered as follows. Numerous inclusion particles aggregate to form smaller clusters firstly, and then they come together into large agglomerates. The agglomerating times of clusters equal in size are different, The shapes of clusters with the same initial condition of agglomeration are also different. The inclusion growth rate by agglomeration increases with increasing shift step length and concentration of particles. The average value of shift step length of particles is decided by the viscosity of molten steel and the size of particles with a great degree. The distribution of agglomerates and the size of clusters vary with the agglomerating time and the average shift step length of particles.