Simulation of Pore Scale Fluid Flow of Sand

Overview

A Micro-CT scan of a coarse sand sample was used to generate a mesh for fluid flow simulation. The image data’s resolution was 4.3µm, showing the solid and air domain of the sand sample. High quality tetrahedral meshes were generated for fluid flow simulation.

Characteristics:

  • Based on Micro-CT image data
  • Automatic segmentation using Threshold tool
  • Scan to mesh in 10 minutes

Thanks to

W. Fourie, D. L. Barnes, University of Alaska, Fairbanks

Image Processing

The soil used in the study was a coarse sand with a mean diameter of 0.55 mm. The image data was segmented within ScanIP using the automated threshold tool. Semi-automated tools such as FloodFill and level set methods can also be used to complete the segmentation.

Mesh Generation

The segmented data was robustly meshed within minutes using Simpleware’s proprietary +FE Grid meshing algorithm. Matching contacts at interfaces and accurate representation of the domains are guaranteed.

Simulation

The fluid flow simulation was exported to COMSOL Multiphysics®. It was possible to show that pore scale fluid flow, modelled by the Navier-Stokes equation, can be used to derive macro parameters of Darcy’s Law such as the hydraulic conductivity. The model allows the calculation of isotropy, tortuosity and dispersivity of the soil in all directions.