HYDRODYNAMICS OF FRACTAL FLOCS DURING SETTLING  

作　　者：ZHANG Jin-feng ZHANG Qing-he 

机构地区：[1]School of Civil Engineering, Key Laboratory of Harbour and Ocean Engineering, Ministry of Education, Tianjin University, Tianjin 300072, China [2]Department of Ocean and Resources Engineering, University of Hawaii at Manoa, HI 96822, USA

出　　处：《Journal of Hydrodynamics》2009年第3期347-351,共5页水动力学研究与进展B辑（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 50779046, 50279029)

摘　　要：The settling and hydrodynamic properties of 3-D fractal flocs in quiescent water are investigated with a numerical model based on the Lattice Boltzmann Method （LBM）, with considering the settling velocity, hydrodynamic drag force and infra-floc flow. The comparisons of floc settling velocities and effective densities indicate that the numerical results present good agreements with observations in field and at laboratory. The results show that the drag force Fo increases with the floc size dr according to the relationship FD ∝ df^3. Moreover, the intra-floc flow field and movement of the pore water provide a better understanding of the intra-floc flow from the microscopic viewpoint. The results also indicate that the lattice Boltzmann method is a promising approach to reveal the mechanisms of the flocculation in aquatic environments.The settling and hydrodynamic properties of 3-D fractal flocs in quiescent water are investigated with a numerical model based on the Lattice Boltzmann Method （LBM）, with considering the settling velocity, hydrodynamic drag force and infra-floc flow. The comparisons of floc settling velocities and effective densities indicate that the numerical results present good agreements with observations in field and at laboratory. The results show that the drag force Fo increases with the floc size dr according to the relationship FD ∝ df^3. Moreover, the intra-floc flow field and movement of the pore water provide a better understanding of the intra-floc flow from the microscopic viewpoint. The results also indicate that the lattice Boltzmann method is a promising approach to reveal the mechanisms of the flocculation in aquatic environments.

关 键 词：Lattice Boltzmann Method （LBM） fractal floc hydrodynamic properties drag force infra-floc flow 

分 类 号：O35[理学—流体力学] TU433[理学—力学]