Li Yishuai, Yonemoto Yukihiro, Yamahata Yuki, Kawahara Akimaro
Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan.
Micromachines (Basel). 2025 Apr 30;16(5):545. doi: 10.3390/mi16050545.
As an important structure of microfluidic devices, microchannels have the advantages of precise flow control and high reaction efficiency. This study investigates experimentally changing the rheological properties of a polyacrylamide (PAM) aqueous solution after flowing through a square microchannel with a hydraulic diameter of 0.5 mm under low Reynolds number and high shear rate conditions. To know the effect of the channel length on the change in viscosity and relaxation time, the length is changed to 100 mm and 200 mm. From the experiment, it is found that both the viscosity and relaxation time of the solution decrease with increasing the shear rate and the microchannel length. Based on the present experimental data, an empirical model is proposed to predict the change ratio of the relaxation time before and after passing through the microchannel, and the calculation with the model has an agreement with the experiment with root-mean-square absolute error of 0.007.
作为微流控装置的重要结构，微通道具有精确流量控制和高反应效率的优点。本研究通过实验研究了在低雷诺数和高剪切速率条件下，聚丙烯酰胺（PAM）水溶液流经水力直径为0.5毫米的方形微通道后流变特性的变化。为了解通道长度对粘度和松弛时间变化的影响，将长度分别改为100毫米和200毫米。实验发现，溶液的粘度和松弛时间均随剪切速率和微通道长度的增加而降低。基于当前实验数据，提出了一个经验模型来预测通过微通道前后松弛时间的变化率，该模型计算结果与实验结果相符，均方根绝对误差为0.007。
