Normal stresses and free surface deformation in concentrated suspensions of noncolloidal spheres in a viscoelastic fluid
Normal stresses and free surface deformation in concentrated suspensions of noncolloidal spheres in a viscoelastic fluid
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粘弹性流体中非胶体球体浓悬浮液的法向应力和自由表面变形
DOI：
10.1122/1.1396356
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发表时间：
2001
影响因子：
3.3
通讯作者：
D. Leighton
中科院分区：
文献类型：
--
作者：
I. E. Zarraga;D. Hill;D. Leighton
非胶体球在恒定粘度的弹性流体中的浓缩悬浮液的流变学特征在于使用旋转板粘度计和轮廓附近的旋转杆的悬浮液表面偏转。结果发现，相对粘度是定量与先前确定的相关性的基础上牛顿流体的悬浮液。另外，第一正应力差N1为正，第二正应力差N2为负。虽然N1和N2的大小随固体体积分数φ的增加而增加，但一般来说，|N1/N2|随着负载的增加而减少。法向应力数据的分析表明，固体微结构的流变学贡献在很大程度上独立于高固体负载（φ ≥ 0.3）下溶解的聚合物。在高浓度下N2的大小接近牛顿流体中类似悬浮液的测量值，而N1的大小可以归因于牛顿流体中的N2。
Concentrated suspensions of noncolloidal spheres in a constant viscosity elastic fluid were characterized rheologically using rotating plate viscometers and profilometry of the suspension surface deflection near a rotating rod. It was found that the relative viscosity was quantitatively consistent with a previously determined correlation for suspensions based on Newtonian fluids. Moreover, the first normal stress difference N1 was found to be positive and the second normal stress difference N2 negative. Although the magnitude of N1 and N2 increased with the solids volume fraction φ, in general the ratio |N1/N2| decreased as loading increased. Analysis of the normal stress data suggests that the rheological contribution of the solids microstructure was in large part independent of that of the dissolved polymers at high solids loading (φ⩾0.3). The magnitude of N2 at high concentrations approached that measured for similar suspensions in Newtonian fluids, while the magnitude of N1 could be attributed to the ...