Ultrasonic velocity profiler applied to explore viscosity-pressure fields and their coupling in ineastic shear thinning vortex streets
Ultrasonic velocity profiler applied to explore viscosity-pressure fields and their coupling in ineastic shear thinning vortex streets
复制标题
超声波速度剖面仪用于探索非弹性剪切稀化涡街中的粘度-压力场及其耦合
DOI：
10.1007/s00348-021-03257-w
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发表时间：
2021
影响因子：
2.4
通讯作者：
Y.Murai
中科院分区：
文献类型：
--
作者：
N.Tiwari;Y.Murai
本文提出了一种利用超声速度剖面技术同时估计非弹性剪切变稀流体粘度场和压力场的方法。该方法采用连续性方程、流变模型和压力泊松方程作为测量速度分布的数据处理序列。应用所提出的方法研究了由于流体剪切变稀特性引起的粘性-压力耦合作用下圆柱体后形成的涡街结构。为了论证，选择质量浓度为0.1%的CMC（羧甲基纤维素）水溶液作为具有剪切变稀特性的工作流体。对于零剪切雷诺数Re = 50-300，成功地重建了低压点的交替交错图案。我们发现，增加Re会导致涡脱落Strouhal数的减少，因为剪切稀化特性支持涡的可持续性。图形摘要
A method for simultaneous estimation of viscosity and pressure fields in inelastic shear-thinning fluids is developed by means of ultrasound velocity profiling technique (UVP). In the method, equation of continuity, rheological model and pressure Poisson equation are incorporated as data processing sequences for measured velocity distributions. The proposed method is applied to study the vortex street structure formed behind a circular cylinder, which shows viscosity–pressure coupling due to shear-thinning property of fluid. For demonstration, aqueous solution of CMC (carboxy methyl cellulose) of weight concentration of 0.1% is chosen as the working fluid with shear-thinning property. An alternating staggered pattern of low-pressure spots is successfully reconstructed for zero-shear-based Reynolds number, Re = 50–300. We have found that increasing Re resulted in decrease in vortex shedding Strouhal number because of vortex sustainability supported by shear-thinning property.Graphical abstract