Experimental and theoretical study of coupled influence of flow velocity increment and particle size on particle retention and release in porous media

作     者：Xing-xin Chen Qi-peng Cai Zhong-han Wu 

作者机构：School of Transportation Southeast University School of Civil Engineering Huaqiao University School of Civil Engineering Beijing Jiaotong University 

出 版 物：《Water Science and Engineering》 (水科学与水工程（英文版）)

年 卷 期：2017年第10卷第3期

页      面：236-245页

核心收录：

学科分类：083001[工学-环境科学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 080704[工学-流体机械及工程] 080103[工学-流体力学] 08[工学] 0807[工学-动力工程及工程热物理] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China(Grant No.51308235) the Natural Science Foundation of Fujian Province of China(Grant No.2015J01209) the Project Funded by the China Postdoctoral Science Foundation(Grant No.2015M580384) 

主　　题：Particle Porous media Retention Release Hydrodynamic force 

摘      要：Experimental and theoretical studies were carried out to investigate the coupled influence of flow velocity increment and particle size on the retention and release of particles in porous media. Particle release was examined through measurement of changes in effluent particle concentrations, and particle retention was assessed through measurement of the final spatial distribution of particles remaining in the soil columns after the experiments. Particle release curves were simulated using a convection-dispersion model that includes the instantaneous release of the line source. Fitted model parameters were used to gain insights into the mechanisms that control particle retention and release. When the flow velocity increment was 0.0435 cm/s, the peak concentration of particles decreased with increasing flow velocity until the latter approached a critical level, beyond which the particle concentration increased. Particle wedging and fouling were considered the primary mechanisms that controlled particle retention and release beyond the critical particle velocity. In experiments with large flow velocity increments, small particles exhibited lower particle mass fraction than large particles as particle wedging and fouling increased with particle size. The range of longitudinal dispersivity decreased with an increasing particle size and flow velocity increment. Moreover, the mean particle velocity increased with the mean interstitial fluid velocity. The mean particle velocity profile was highly sensitive to the particle size at low velocity increments. In general,particle release rates increased with both flow velocity and velocity increment. The mass of the released particles provides further evidence that particle wedging and fouling are the major factors that control particle release in sand columns.