HR: 14:25h
AN: H13K-03    [Abstracts]
TI: Particles Tracking in Transparent Matched Index of Refraction Porous Media
AU: * Lachhab, A
EM: lachhab@susqu.edu
AF: Earth and Environmental Science, Susquehanna University, 514 University Ave, Selinsgrove, PA 17870, United States
AU: Zhang, Y
EM: you-kuan-zhang@uiowa.edu
AF: Department of Geoscience, The University of Iowa, Trowbridge Hall North Capitol St., Iowa City, IA 52242, United States
AB: An inexpensive non-invasive three-dimensional particle tracking velocimetry system was designed and constructed to investigate tracer particles' movement in a match-index-refraction (MIR) porous medium. This flow visualization experiment was carried out by releasing and recording neutrally-buoyant tracer particles in both homogeneous and heterogeneous MIR materials. Particles were released and tracked in the two materials and a three-dimensional trajectory of each particle was recorded using two video camcorders. This technique consisted of using images from two cameras which were placed orthogonal to the main axis of the porous material flow cell. The particle trajectories were obtained based on image processing and via Three-Dimensional Particle Tracking (3DPT) technique. In this technique a Lagrangian analysis was used, and the coordinates and the velocity components of each tracer particle were accurately determined. The experiment's results have shown the following main conclusions: 1) the particle's trajectory and spreading are affected by the size of the tracer particles and are sensitive to their initial locations; 2) small-scale heterogeneity may enhance the early-time dispersion while large-scale heterogeneity may control the late-time asymptotic dispersion; 3) an effective porosity (ne) may exist in the heterogeneous medium which may be significantly smaller than the total porosity and ne should be viscosity-dependent. For the same porous medium, the higher the viscosity, the smaller the effective porosity; 4) the distributions of the longitudinal velocities were found to be lognormal while the distribution of the transverse velocities was found to be Gaussian.
DE: 1847 Modeling
SC: Hydrology [H]
MN: 2007 Fall Meeting