当前位置: X-MOL 学术Sci. Adv. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Shaken and stirred: Random organization reduces viscosity and dissipation in granular suspensions.
Science Advances ( IF 11.7 ) Pub Date : 2018-Mar-01 , DOI: 10.1126/sciadv.aar3296
Christopher Ness 1 , Romain Mari 2, 3 , Michael E Cates 2
Affiliation  

The viscosity of suspensions of large (≥10 μm) particles diverges at high solid fractions due to proliferation of frictional particle contacts. Reducing friction, to allow or improve flowability, is usually achieved by tuning the composition, either by changing particle sizes and shapes or by adding lubricating molecules. We present numerical simulations that demonstrate a complementary approach whereby the viscosity divergence is shifted by driven flow tuning, using superimposed shear oscillations in various configurations to facilitate a primary flow. The oscillations drive the suspension toward an out-of-equilibrium, absorbing state phase transition, where frictional particle contacts that dominate the viscosity are reduced in a self-organizing manner. The method can allow otherwise jammed states to flow; even for unjammed states, it can substantially decrease the energy dissipated per unit strain. This creates a practicable route to flow enhancement across a broad range of suspensions where compositional tuning is undesirable or problematic.

中文翻译:

摇动和搅拌:随机组织降低了颗粒悬浮液的粘度和耗散。

由于摩擦颗粒接触的扩散,大颗粒(≥10 μm)悬浮液的粘度在高固体分数下发散。减少摩擦,以允许或改善流动性,通常通过调整组成来实现,要么通过改变颗粒大小和形状,要么通过添加润滑分子。我们提出的数值模拟演示了一种互补方法,即通过驱动流调整来改变粘度散度,在各种配置中使用叠加的剪切振荡来促进初级流动。振荡将悬浮液推向不平衡的吸收状态相变,其中主导粘度的摩擦颗粒接触以自组织方式减少。该方法可以让原本阻塞的状态流动;即使对于未受干扰的状态,它可以大大降低每单位应变消耗的能量。这创造了一条切实可行的途径,可以在范围广泛的悬浮液中增强流动性,在这些悬浮液中,成分调整是不受欢迎的或有问题的。
更新日期:2018-03-31
down
wechat
bug