Author(s): T. Ueno; R. R. Giri; K. Nishida; K. Sato
Linked Author(s):
Keywords: DNAPL; Dispersion coefficient; Porous medium model; Mass concentration
Abstract: Gravitational dispersion may play significant role in DNAPL (dense non-aqueous phase liquid) transport in groundwater. Fingering (continuous phase) and droplet (discrete particles) settlement are two examples on gravitational dispersion of DNAPL in groundwater environment. Gravitational dispersion of small spherical solid particles and TCE (trichloroethylene) droplets through water-saturated porous medium models are dealt in this paper. The experimental set-up consisted of single-layered glass sphere media and visualizing equipments with high accuracy. The experimental results, based on ergodic theorem, are compared with analytical solution of one-dimensional gravitational dispersion equation. The results showed that dispersion of the particles and droplets could be well characterized by the present study. Values of non-dimensional ratio (Dz/ν, ν: kinematic viscosity) for solid particles and TCE droplets varied from 10 to 30, and 4 to 5.5, respectively. Particle and droplet Reynolds number varied between 74 and 230 in both cases. Higher density and rigidity of the solid particles resulted to bigger dispersion coefficient values (Dz) compared to TCE droplets. The coefficient values increased with bigger pore size in both cases.
Year: 2003