Pressure-driven suspension flow near jamming.
Pressure-driven suspension flow near jamming.
复制标题
压力驱动的悬浮液流动接近堵塞。
DOI：
10.1103/physrevlett.114.088301
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发表时间：
2015
影响因子：
8.6
通讯作者：
J. Desroches
中科院分区：
文献类型：
--
作者：
S. Oh;Yi;D. Garagash;B. Lecampion;J. Desroches
本文报道了固体体积分数(ϕ_{0})高达0.55的悬浮液在管道中流动的磁共振成像测量结果。我们可视化并量化了不同轴向位置处管道内ϕ和速度的空间分布。对于稠密悬浮液(ϕ_{0}>；0.5)，我们发现了与已知的较低ϕ_{0}情况不同的行为。我们的实验结果表明，在干扰区域内(宏观剪切率为零)，从外部边界的干扰极限ϕ_m}≈0.58到中心的随机紧密堆积极限ϕ_{rcp}≈0.64。此外，我们还表明，摩擦流变学可以很好地捕捉到ϕ和速度分布，这既考虑了堵塞区域的进一步压实，也考虑了法向应力差异。
We report here magnetic resonance imaging measurements performed on suspensions with a bulk solid volume fraction (ϕ_{0}) up to 0.55 flowing in a pipe. We visualize and quantify spatial distributions of ϕ and velocity across the pipe at different axial positions. For dense suspensions (ϕ_{0}>0.5), we found a different behavior compared to the known cases of lower ϕ_{0}. Our experimental results demonstrate compaction within the jammed region (characterized by a zero macroscopic shear rate) from the jamming limit ϕ_{m}≈0.58 at its outer boundary to the random close packing limit ϕ_{rcp}≈0.64 at the center. Additionally, we show that ϕ and velocity profiles can be fairly well captured by a frictional rheology accounting for both further compaction of jammed regions as well as normal stress differences.