Rheological characterization and flow reconstruction of polyvinylpyrrolidone aqueous solutions by means of velocity profiling-based rheometry
Rheological characterization and flow reconstruction of polyvinylpyrrolidone aqueous solutions by means of velocity profiling-based rheometry
复制标题
通过基于速度分布的流变测定法对聚乙烯吡咯烷酮水溶液进行流变表征和流动重建
DOI：
10.1007/s00348-022-03489-4
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发表时间：
2022
影响因子：
2.4
通讯作者：
Murai Yuichi
中科院分区：
文献类型：
--
作者：
Ohie Kohei;Yoshida Taiki;Tasaka Yuji;Sugihara-Seki Masako;Murai Yuichi
提出了一种非牛顿流体速度场的重建方法，该方法保证了与实验评价流变特性的一致性。聚乙烯吡咯烷酮（PVP）水溶液的测试流体通常被假定为牛顿，而它是粘弹性的非稳态剪切流的限制条件。通过流变学绘图进行用于计算粘弹性对施加的剪切变形及其时间尺度的依赖性的综合评价[Ohie等人，“利用超声纺丝流变仪表征聚合物溶液的有效流变学映射”，Exp. Fluids，63，2（2022）]，其基于基于速度分布的流变学。揭示了粘弹性产生的剪切速率和振荡频率条件。一个新提出的收敛计算方法是适应这个PVP解决方案作为一个示范重建速度场从实验获得的数据集。所提出的计算方案被设计成不需要为每种复杂流体建立单独的流变模型。预测的双同心圆柱之间的振荡剪切流在有和没有非牛顿特性的情况下明显不同。考虑非牛顿特性的速度分布预测结果与验证实验结果吻合较好。这表明所提出的收敛计算方法结合实验评估的流变特性的有效性。图形摘要
A method for reconstructing velocity fields of non-Newtonian fluids is proposed, which ensures consistency with experimentally evaluated rheological properties. A polyvinylpyrrolidone (PVP) aqueous solution for the test fluid is generally assumed as Newtonian, while it is viscoelastic in limited conditions of unsteady shear flows. Comprehensive evaluation for figuring out the dependence of viscoelasticity on applied shear deformation and its timescale was conducted by rheology mapping [Ohie et al., “Effective rheology mapping for characterizing polymer solutions utilizing ultrasonic spinning rheometry”, Exp. Fluids, 63, 2 (2022)], which is based on a velocity profiling-based rheometry. It revealed the conditions of shear rate and oscillation frequency where the viscoelasticity emerges. A newly proposed convergence calculation method was adapted to this PVP solution as a demonstration for reconstructing velocity fields from the experimentally obtained data set. The proposed calculation scheme is designed not to need a separate rheological model for each complex fluid. The predicted oscillatory shear flows between double concentric cylinders were clearly different with and without the non-Newtonian characteristic. The predicted velocity profiles considering the non-Newtonian characteristic were in good agreement with verification experimental results. This indicates validity of the proposed convergence calculation method combined with the experimentally evaluated rheological properties.Graphical abstract