Dissolution mass transfer from the trapped phase to the flowing phase in porous media occurs in various hydrogeology processes. One of the important phenomena is dissolution fingering and its effect on dissolution mass transfer. In this work, dissolution mass transfer in porous media with various particle sizes and distribution was investigated in pore scale and meso-scale by using X-ray microcomputed tomography. The specific interfacial area and mass transfer coefficient were measured by following the representative elementary volume concept, and the effect of dissolution fingering was evaluated. Linear instability theory was used for the prediction of dissolution finger width () at the onset of dissolution fingering. Although dissolution fingering tends to develop when the porous media container diameter () is smaller than half of , its effect on mass transfer coefficient starts to occur when is larger than the whole . Starting this point, dissolution fingering decreases the mass transfer coefficient by three times. For validation, an additional experiment with a larger porous media container size was performed, and three dissolution fingers were successfully observed. Their size was found to be comparable with the theoretical prediction based on linear instability theory.

中文翻译：

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溶出指对三维多孔介质传质速率的影响

多孔介质中从困相到流动相的溶解传质发生在各种水文地质过程中。重要的现象之一是溶出指状及其对溶出传质的影响。在这项工作中，通过使用 X 射线显微计算机断层扫描，在孔隙尺度和中尺度上研究了具有各种粒径和分布的多孔介质中的溶解传质。通过遵循代表性的基本体积概念测量比界面面积和传质系数，并评估溶出指法的影响。线性不稳定性理论用于预测溶出指状开始时的溶出指宽度 ( )。尽管当多孔介质容器直径 ()小于一半，当大于整体时，其对传质系数的影响开始出现。从这一点开始，溶出指法将传质系数降低了三倍。为了验证，使用更大的多孔介质容器尺寸进行了额外的实验，并成功观察到三个溶出指。发现它们的大小与基于线性不稳定性理论的理论预测相当。