Pressure Drop for Gas and Polymer Aqueous Solution Two-Phase Flows in Horizontal Circular Microchannel
Pressure Drop for Gas and Polymer Aqueous Solution Two-Phase Flows in Horizontal Circular Microchannel
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DOI：
10.1007/s10494-020-00127-z
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发表时间：
2020-03
期刊：
影响因子：
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通讯作者：
A. Kawahara;Y. Yonemoto;Yoichi Arakaki
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文献类型：
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作者：
A. Kawahara;Y. Yonemoto;Yoichi Arakaki
研究了气液两相流在石英管（直径0.25 mm）水平圆形微通道内的压降。以三种不同质量浓度的聚合物水溶液（羧甲基纤维素钠、黄原胶和聚丙烯酰胺）为非牛顿液体，以氮气为试验气体。流动条件变化范围为液相体积通量l = 0.12 ~ 0.58 m/s，气相体积通量g = 0.03 ~ 0.84 m/s。在这些气液组合条件下观察到的流动模式都是段塞流或泰勒流。在单相流体流动的初步实验中，得到了非牛顿流体和牛顿流体的达西摩擦因数数据，用广义雷诺数计算得到的摩擦因数与hagens - poiseuille流动的摩擦因数一致。由于聚合物溶液的剪切减薄效应与剪切速率的关系，两相压降随聚合物类型的不同而变化。此外，聚合物溶液的弹性取决于其分子量，可能会影响压降特性。将两相压降的实验数据与现有模型计算结果进行了比较。对比结果表明，如果对每种聚合物水溶液采用模型中所需的均匀粘度和两相摩擦倍率的适当相关性，则现有模型可以预测本文的数据。此外，如果对每种聚合物溶液的拟合参数发生变化，则单元胞模型可以将压降数据关联起来。
This study investigated pressure drop for gas and non-Newtonian liquid two-phase flows in a horizontal circular microchannel (0.25 mm I.D.) made of fused silica tube. Three kinds of polymer aqueous solutions (sodium carboxymethyl cellulose, xanthan gum and polyacrylamide) with different mass concentration were used as non-Newtonian liquids, while the nitrogen gas was used as the test gas. The flow conditions were varied in the range of the volumetric fluxjL= 0.12–0.58 m/s for the liquid phase and the volumetric fluxjG= 0.03–0.84 m/s for the gas phase. The flow patterns observed for these combinations of gas–liquid conditions were all slug flow or Taylor flow. In the preliminary experiment for single-phase liquid flows, Darcy friction factor data were obtained for non-Newtonian liquid as well as Newtonian one, and the obtained friction factor agreed with that for Hagen-Poiseuille flow by using generalized Reynolds number. The two-phase pressure drop varied depending on types of polymer because of the shear thinning effects of polymer solutions with the shear rate. In addition, the elasticity of polymer solutions depending on its molecular weight might affect the pressure drop characteristics. The experimental data of two-phase pressure drop have been compared with the result calculated by existing models. As the comparison results, the existing models predicted the present data if the appropriate correlations for homogeneous viscosity and two-phase friction multiplier needed in the models were used for each polymer aqueous solution. In addition, the unit cell model could correlate the pressure drop data if a fitting parameter changes against each polymer solution.