Compute Particle Diffusion and Advection


AddiDict traces the movement of particles by advection and diffusion. Such a tracer experiment in a 3D structure starts by initially placing the particles, and then tracking the movement of those particles until they either leave the computational domain or arrive at a structure surface that collects those particles.

Advection is governed by an external pressure drop, and the flow field is computed using the solvers available in FlowDict. Diffusion is modeled by a random walk algorithm that can either describe the Brownian motion of large particles in a surrounding fluid, or the diffusive motion of the molecules themselves.

In post-processing, AddiDict computes break-through curves and time dependent particle concentrations. Using the GeoLab library, it is also possible to import and analyze all particle trajectories in Matlab.

Examples of Applications

Studies on the transport of particles in suspensions and emulsions in porous media in industrial and natural processes, such as:

  • Wastewater 
  • Subsurface propagation of pollutants 
  • Fouling of membranes 
  • Seawater injection in oil reservoir
  • Particle-adsorbed organic contaminants in groundwater

AddiDict Features

AddiDict allows to:

  • Place particles in arbitrary starting positions
  • Model flow and diffusion through pores and porous voxels. A porous voxel is a grid cell that contains unresolved pores.

The computation of the flow field and the particle tracking is parallelized for shared memory workstations or distributed memory clusters.

Additional modules needed?

  • The GeoDict Base package is needed for basic functionality.
  • ImportGeo-Vol: for the import and segmentation of the µCT images and the generation of the 3D structural models
  • FlowDict: for the computation of the flow field