A generalized view of foam drainage: Experiment and theory
A generalized view of foam drainage: Experiment and theory
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DOI：
10.1021/la9913147
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发表时间：
2000-07-25
期刊：
影响因子：
3.9
通讯作者：
Stone, HA
中科院分区：
文献类型：
--
作者：
Koehler, SA;Hilgenfeldt, S;Stone, HA
提出了一种利用荧光素染料测定泡沫塑料中液体体积分数的时空变化的实验方法。该方法用于在三种类型的实验中定量研究液体再分配(排水)：强制排水、自由排水和脉冲排水。排液速度等特征量与实验参数呈幂函数关系，这与传统的基于Poiseuille流的泡沫排液模型不一致。为了得到理论上的描述，用一个能量参数来推广泡沫排水方程，该方程考虑了流道和液体网络的节点(或顶点，它们是四个流道的结点)中的粘性耗散。在节点耗散占主导地位的极限情况下，该模型与所有三种排水试验的结果都很好地吻合。
A new experimental method is presented using fluorescein dye to determine the spatial and temporal variations of the liquid volume fraction in aqueous foams. This method is used for quantitative studies of liquid redistribution (drainage) in three types of experiments: forced, free, and pulsed drainage. Characteristic quantities, such as the drainage velocity, show power-law dependences on experimental parameters that are inconsistent with traditional foam drainage models based on Poiseuille-type flow in the liquid-carrying channels (Plateau borders) of the foam. To obtain a theoretical description, the foam drainage equation is generalized using an energy argument which accounts for viscous dissipation in both the channels and the nodes (or vertices, which are the junctions of four channels) of the liquid network. Good agreement with results for all three types of drainage experiments is found when using this new model in the limit where the dissipation is dominated by the nodes.