4.7 Article

Three-dimensional visualization and modeling of capillary liquid rings observed during drying of dense particle packings

出版社

PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.ijheatmasstransfer.2021.121505

关键词

Convective drying; X-ray microtomography; Liquid structure; 3D capillary rings; Discrete pore network modeling

资金

  1. German Research Foundation (DFG) [GRK 1554, CRC/TRR 287]
  2. Higher Education Commission (HEC) of Pakistan

向作者/读者索取更多资源

Experimental and numerical studies on convective drying of capillary porous media under slow isothermal conditions show that capillary liquid rings near particle-particle contacts significantly accelerate the drying process, act as additional hydraulic pathways, and lead to a spatially homogeneous distribution of liquid down to low saturation, providing valuable insights for complex multiphase flow phenomena in porous media.
Experimental and numerical pore network simulation studies on convective drying of capillary porous media under slow isothermal conditions are presented in this work. As a physical model of a real capillary porous medium, two dense packings of particles filled with monodisperse spherical glass beads (mean diameter 0.8 mm) and initially saturated either with distilled water or with a salt solution are prepared. Two controlled drying experiments with these packings are carried out using a custom-made setup installed in a lab-scale X-ray microtomograph. Based on in-situ tomograms (voxel size 16.4 mu m) the time evolution of three-dimensional (3D) structures of liquid and salt deposit in the packings during drying are characterized. The respective results clearly demonstrate the formation of capillary liquid rings at the wedge-shaped pores located near the particle-particle contacts. The rings remain connected over a long distance to the packing surface during a significant period of drying. To highlight the crucial impact of liquid rings on drying, a 3D discrete pore network model that explicitly accounts for the ring effect is developed. Pore network simulations in the presence and absence of this effect are compared with measurements in terms of drying kinetics and saturation profiles. It is found that liquid rings act as additional hydraulic pathways for moisture transport from the interior of the pore/particle network to the surface and thus notably accelerate the drying process, and they lead to a spatially homogeneous distribution of the liquid down to low saturation. This study can be considered as a step forward in discrete modeling of drying of capillary porous media with 3D secondary capillary structures and should be of interest for various applications in the field of complex multiphase flow phenomena in porous media. (C) 2021 Elsevier Ltd. All rights reserved.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据