Fluctuations and diffusion in sheared athermal suspensions of deformable particles
Fluctuations and diffusion in sheared athermal suspensions of deformable particles
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DOI：
10.1209/0295-5075/108/68006
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发表时间：
2014-03
期刊：
影响因子：
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通讯作者：
M. Gross;T. Krüger;F. Varnik
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文献类型：
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作者：
M. Gross;T. Krüger;F. Varnik
我们分析了弹性胶囊(红细胞)剪切非热悬浮液中颗粒位移和应力的涨落。当体积分数从稀释区向高浓度区变化时，我们的数值模拟揭示了涨落方差和驰豫时间的不同特征的幂规律区域。在阻塞阶段和高剪切速率下，发现了偏离纯维预测的反常标度指数。通过动力学论证和考虑了颗粒之间局部流体流动的耗散平衡模型，对观察到的行为进行了合理化。我们的发现支持了稠密悬浮液的流变性本质上是由非仿射位移控制的观点。
We analyze fluctuations of particle displacements and stresses in a sheared athermal suspension of elastic capsules (red blood cells). Upon variation of the volume fraction from the dilute up to the highly concentrated regime, our numerical simulations reveal different characteristic power-law regimes of the fluctuation variances and relaxation times. In the jammed phase and at high shear rates, anomalous scaling exponents are found that deviate from pure dimensional predictions. The observed behavior is rationalized via kinetic arguments and a dissipation balance model that takes into account the local fluid flows between the particles. Our findings support the view that the rheology of dense suspensions is essentially governed by the non-affine displacements.