On rheophysics of high-concentrated suspensions
On rheophysics of high-concentrated suspensions
复制标题
高浓度悬浮液的流变物理学
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
L. Ryashko
中科院分区：
文献类型：
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作者：
I. Bashkirtseva;A. Zubarev;L. Iskakova;L. Ryashko
高浓度固体颗粒悬浮液的实验表明，当悬浮液中的剪切速率超过某一临界值时，其粘度增加几倍甚至几个数量级，这取决于颗粒的浓度和形状以及载液的物理化学组成。实验发现，在一定的剪切速率范围内，这也是由悬浮液的组成预先确定的，稳定的流动变得不稳定，并且在几秒钟的时间内在流动中出现规则或随机振荡。针对这些现象提出了一种理论，该理论基于以下事实：粘度随剪切速率的增加由颗粒之间的接触摩擦来解释，而当悬浮液的微分粘度获得负值时，就会出现流动振荡。
Experiments with high-concentrated suspensions of solid particles show that that their viscosity increases by several times or even orders of magnitude, when the shear rate in the suspensions exceeds some critical value, which depends on the concentration and shape of particles and the physicochemical composition of carrier liquids. It is experimentally found that, within a certain range of shear rates, which is also predetermined by the composition of the suspensions, a steady flow becomes unstable, and regular or random oscillations arise in the flow with a period of several seconds. A theory is proposed for these phenomena, which is based on the fact that the increase in the viscosity with the shear rate is explained by the contact friction between particles, while the flow oscillations arise when the differential viscosity of a suspension acquires negative values.