Seto Ryohei, Botet Robert, Auernhammer Günter K, Briesen Heiko
Technische Universität München, Freising, Germany.
Eur Phys J E Soft Matter. 2012 Dec;35(12):9805. doi: 10.1140/epje/i2012-12128-4. Epub 2012 Dec 12.
A method to couple interparticle contact models with Stokesian dynamics (SD) is introduced to simulate colloidal aggregates under flow conditions. The contact model mimics both the elastic and plastic behavior of the cohesive connections between particles within clusters. Owing to this, clusters can maintain their structures under low stress while restructuring or even breakage may occur under sufficiently high stress conditions. SD is an efficient method to deal with the long-ranged and many-body nature of hydrodynamic interactions for low Reynolds number flows. By using such a coupled model, the restructuring of colloidal aggregates under shear flows with stepwise increasing shear rates was studied. Irreversible compaction occurs due to the increase of hydrodynamic stress on clusters. Results show that the greater part of the fractal clusters are compacted to rod-shaped packed structures, while the others show isotropic compaction.
介绍了一种将粒子间接触模型与斯托克斯动力学（SD）相结合的方法，用于模拟流动条件下的胶体聚集体。接触模型模拟了簇内颗粒间粘性连接的弹性和塑性行为。因此，簇在低应力下可以保持其结构，而在足够高的应力条件下可能会发生重组甚至破裂。SD是处理低雷诺数流动中流体动力相互作用的长程和多体性质的有效方法。通过使用这种耦合模型，研究了剪切速率逐步增加的剪切流作用下胶体聚集体的重组。由于作用在簇上的流体动力应力增加，发生了不可逆压实。结果表明，大部分分形簇被压实成棒状堆积结构，而其他簇则呈现各向同性压实。
