Clogging mechanism of pervious concrete: From experiments to CFD-DEM simulations
Clogging mechanism of pervious concrete: From experiments to CFD-DEM simulations
复制标题
透水混凝土的堵塞机理：从实验到CFD-DEM模拟
DOI：
10.1016/j.conbuildmat.2020.121422
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发表时间：
2021-01-12
影响因子：
7.4
通讯作者：
Li, Bo
中科院分区：
文献类型：
--
作者：
Nan, Xuan;Wang, Zekun;Li, Bo
研究了不同粒径的地表微颗粒通过多孔渗透材料的流动特性和堵塞规律。结合计算流体力学-离散单元法（CFD-DEM）模拟，对多孔渗透材料封堵地表径流的试验进行了分析。本研究选取粒径小于0.3 mm、0.3-0.6 mm、0.6-0.9 mm和0.9-2.2 mm的标准石英砂颗粒进行透水材料堵塞实验。通过与实验记录的渗透系数进行比较，验证了CFD-DEM耦合模型的正确性。通过该模型详细分析了渗透速度、流体总力以及不同尺寸颗粒的空间分布，确定了不同时间颗粒位置的变化对渗透材料堵塞的影响。试验和数值模拟结果表明，在渗流初期，表层颗粒迅速堵塞，导致渗透系数明显降低。由于多孔可渗透材料的小孔结构，尺寸为0.6至2.2 mm的颗粒被阻挡在表面层的2 cm内，导致阻挡尾流中的0.3-0.6 mm颗粒。然而，小于0.3 mm的颗粒可以深入渗透材料，并在深层孔隙中积聚，最终随着时间的演变形成深层堵塞。对上述结果进行了特征尺度归一化处理，发现了堵塞现象中存在的自相似性。整个研究实现了实验、数值模拟和无因次分析的统一，所获得的规律可为进一步开展透水材料封堵的相关研究提供指导。(C)2020爱思唯尔有限公司保留所有权利。
The flow characteristics and clogging laws of micro particles with different sizes on ground surface passing through porous infiltrated materials were investigated. Experiments with surface runoff plugging on porous infiltrated materials were conducted and analyzed, combined with coupled computational fluid dynamics - discrete element method (CFD-DEM) simulations. In the study, the standard quartz sand particles of less than 0.3 mm, 0.3-0.6 mm, 0.6-0.9 mm and 0.9-2.2 mm were selected for the permeable material clogging experiment. The CFD-DEM coupling model was verified by comparing it with the recorded permeability coefficient from the experiment. The seepage velocity, total force of the fluid and spatial distribution of particle with different sizes were analyzed in detail by the model, and the influence of the change of the particle position at different time on the blockage of permeable material was determined. The results of experiments and numerical simulations indicate that in the initial stage of seepage, the rapid formation of clogging of the particles in the surface layer leads to an evident decrease in the permeability coefficient. Due to the small pore structures of the porous permeable material, the particle with sizes from 0.6 to 2.2 mm are blocked within 2 cm of the surface layer, resulting in obstructing 0.3-0.6 mm particles in the wake. However, particles less than 0.3 mm can penetrate deep into the permeable material, and accumulate in the deep pores, eventually forming a deep blockage with evolution of time. The above results are also normalized with characteristic scales, and self-similarity existed in the clogging phenomenon are discovered. The whole research realizes the unification of experiment, numerical simulation, and dimensionless analysis, and it is believed that the obtained laws can provide guidance for further relevant studies on the plugging of pervious materials. (C) 2020 Elsevier Ltd. All rights reserved.