剪切场作用下团聚体分散的计算机模拟

SIMULATION OF DISPERSION OF FRACTAL AGGLOMERATES IN SHEAR FLOW FIELD

利用计算机模拟研究了三种简单立方网格上的三维分形团聚体的团聚过程,并对团聚体在简单剪切流场中分散规律进行了研究。结果表明,团聚体在简单剪切场作用下的分散与其团聚机理和分形维数有关。分形维数较小的DLA团聚体分散所需的临界应力随团聚体增大而减小;分形维数最大的Eden团聚体的临界应力随其增大而增大;LTA团聚体的临界应力随其增大而变化不大。研究还表明,随着破裂面位置向团聚体内部推进,三种团聚体分散所需的流场临界应力都显示了增大的趋势。

Three different kinds of fractal aggregates, say, DLA, Eden, LTA were simulated based on simple cubic lattice by Monte Carlo method and the influence of their structure on the dispersion behavior in simple shear flow was studied. The critical shear stress of DLA aggregate for dispersion in simple shear flow, which has the lowest fractal dimension, decreases with the increase of its size that of Eden aggregate which has the highest fractal dimension increases as its size increasing that of LTA aggregate is independent of its size. It is also showed that the critical stress of the fractal aggregates is influenced by their internal structures.