Tsuritani Kanoko, Inasawa Susumu
Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology 2-24-16 Nakacho, Koganei Tokyo 184-8588 Japan
Department of Applied Physics and Chemical Engineering, School of Engineering, Tokyo University of Agriculture and Technology 2-24-16 Nakacho, Koganei Tokyo 184-8588 Japan.
RSC Adv. 2021 Oct 8;11(52):33093-33101. doi: 10.1039/d1ra06392h. eCollection 2021 Oct 4.
We investigated the kinetics of water imbibition in polydisperse foams. We used a Hele-Shaw cell, and horizontal imbibition was observed for a timescale of up to 10 s in which the gravity effect was negligible. While several papers have reported kinetics for imbibition in foams, imbibition kinetics in polydisperse foams and its variations in longer timescales are not well understood. The tip position of imbibition was proportional to the square root of time in the initial stage of imbibition, but it showed plateauing in the late stage of imbibition. We evaluated the proportional constant in the initial stage of imbibition as a kinetic constant for the time-dependent increase in the tip position, which showed a clear dependency on the initial and final water volume fractions in the foams. Conversely, the mean initial radius of the curvature and the channel length in the Plateau borders did not show any clear correlations with , although both valuables are frequently used in modeling for liquid imbibition in foams. On the basis of the dependence, the correlation of with the water volume fraction and the increase in the water volume fraction during imbibition, we proposed a simple equation to describe the tip position over the entire period of imbibition. We used them to scale all of the experimental data, which showed good agreement with the theoretical line. This clearly showed that the water volume fraction in the foams during imbibition was the key factor to quantitatively describe the rate of water imbibition. Features in the kinetics of imbibition were discussed.
我们研究了多分散泡沫中吸水的动力学。我们使用了一个赫勒-肖槽，观察到水平吸水过程在长达10秒的时间尺度内，重力效应可忽略不计。虽然已有几篇论文报道了泡沫中吸水的动力学，但多分散泡沫中的吸水动力学及其在更长时间尺度上的变化尚未得到很好的理解。吸水的尖端位置在吸水初始阶段与时间的平方根成正比，但在吸水后期呈现平稳状态。我们将吸水初始阶段的比例常数评估为尖端位置随时间增加的动力学常数，该常数明显依赖于泡沫中的初始和最终水体积分数。相反，尽管在泡沫中液体吸水建模中经常使用这两个值，但普朗特边界中的平均初始曲率半径和通道长度与该常数没有任何明显的相关性。基于该常数的依赖性、其与水体积分数的相关性以及吸水过程中水体积分数的增加，我们提出了一个简单的方程来描述整个吸水过程中的尖端位置。我们用它们对所有实验数据进行标度，结果与理论曲线吻合良好。这清楚地表明，吸水过程中泡沫中的水体积分数是定量描述吸水速率的关键因素。文中讨论了吸水动力学的特征。
