Nonlinear rheology of a highly supercooled liquid
Nonlinear rheology of a highly supercooled liquid
复制标题
高度过冷液体的非线性流变学
DOI：
--
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
A. Onuki
中科院分区：
文献类型：
--
作者：
R. Yamamoto;A. Onuki
本文采用分子动力学方法研究了二维过冷流体在剪切流动中的非线性流变特性。当剪切速率超过α弛豫时间的倒数τα时，粘度表现出明显的剪切变稀行为。粒子对之间的键断裂事件被发现集体发生在集群中。这种团簇的特征尺寸随温度的降低而增大，随温度的升高而迅速减小，增大到B（）1/4.这里1/τB（）是键断裂率，对于τα 1，键断裂率趋于1/τα，并且随着τα 1而增长。在玻璃态下粘度为τB（）量级。
We numerically examine nonlinear rheology of a highly supercooled two-di men sional fluid in shear flow via molecular-dynamics simulation. The viscosity exhibits marked shear-thinning behavior when the shear rate exceeds the inverse of the α relaxation time τα. Bond breakage events among particle pairs are found to occur collectively in clusters. The characteristic size ξ of such clusters grows strongly with lowering the temperature and decreases rapidly with increasing as ξ ~ τb()1/4. Here 1/τb() is the bond breakage rate tending to 1/τα for τα 1 and growing as for τα 1. The viscosity is of order τb() in glassy states.