Comparing Measured and Lattice-boltzmann Simulated Saturated Hydraulic Conductivities of A Three-dimensional Porous Medium With Respect To The Image Resolution
Abstract
This study is embedded in a concept of upscaling hydraulic properties of a porous medium from the pore scale to the continuum scale. The basic idea is that all simu- lations of waterflow and solute transport are based only on structural information at each scale.
As a first test of our concept, we compared permeability measurements on the contin- uum scale with results of a Lattice-Boltzmann (LB) simulation on the pore scale. The investigated material was a sintered borsilicate glass with the advantage of high me- chanical stability. The permeability measurements were carried out on a column with 5.6 cm diameter and 9.6 cm height. From the column we took a cylindric subsample with 6.8 mm diameter and 7.1 mm height to obtain a three-dimensional image of the pore structure by high resolution x-ray tomography. This image was binarized to serve as the basis for the LB simulations. Over the last years, it has been shown that the LB method is a useful tool for modeling flow processes. This is especially the case for its application to complex geometries like porous media. But one has to take into account that the result of the LB simula- tion depends on the image resolution. Therefore, we used image processing tools to enhance the resolution and present a grid refinement technique in a way that we could reproduce the measured permeability. Additionally, in the case of multiphase flow, the image resolution has a larger impact on the LB simulation and our results become even more important.- Publication:
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EGS General Assembly Conference Abstracts
- Pub Date:
- 2002
- Bibcode:
- 2002EGSGA..27.3090S