Fluctuations in shear-banded flow seen by NMR velocimetry
Fluctuations in shear-banded flow seen by NMR velocimetry
复制标题
核磁共振测速法观察到的剪切带流波动
DOI：
10.1209/epl/i2003-00613-1
复制
发表时间：
2003
期刊：
影响因子：
1.8
通讯作者：
P. Callaghan
中科院分区：
文献类型：
--
作者：
W. Holmes;M. R. Lopez;P. Callaghan
磁共振测速测量，蠕虫状胶束系统10%w/v氯化十六烷基吡啶/水杨酸钠在盐水中，揭示了存在广泛变化的速度在每一个点的整个差距的同心圆柱Couette细胞在受控的应变速率条件下。速度起伏的相关时间长于NMR实验中的速度编码时间54 ms，短于4 h的实验时间。使用本构模型包括两个高剪切速率分支，沿着与应力波动，我们能够准确地表示所观察到的速度分布。
Magnetic-resonance velocimetry measurements, on the wormlike micelle system 10% w/v cetylpyridinium chloride/sodium salicylate in brine, reveal the existence of widely varying velocities at each point across the gap of a concentric cylinder Couette cell under controlled strain rate conditions. The correlation time for velocity fluctuations is longer than 54 ms, the velocity encoding time in the NMR experiment, and shorter than the 4 h experiment time. Using a constitutive model comprising two high-shear-rate branches, along with stress fluctuations, we are able to accurately represent the observed velocity distributions.