Microfluidics and Nanofluidics

, Volume 4, Issue 3, pp 257–260

Determination of the effective diffusion coefficient in porous media including Knudsen effects

  • Deqiang Mu
  • Zhong-Sheng Liu
  • Cheng Huang
  • Ned Djilali
Short Communication

DOI: 10.1007/s10404-007-0182-3

Cite this article as:
Mu, D., Liu, ZS., Huang, C. et al. Microfluid Nanofluid (2008) 4: 257. doi:10.1007/s10404-007-0182-3

Abstract

A 3-D bond pore network model is presented and used to evaluate the effect of pore size and connectivity on the effective diffusion coefficient in random porous media. The control equations of the system are set up and the simulation method is discussed. The simulation results show that when the average pore size dm < 1 μm, the effective diffusion coefficient is strongly dependent on pore size. The analysis shows that Knudsen and bulk diffusion effects can be decoupled, and for any given diffusion conditions, the effect coefficient accounting for Knudsen diffusion can be obtained. Thus, the effect of pore size can been readily accounted for by correcting the bulk effective diffusivity with the Knudsen effect coefficient. The simulations also show that the percolation threshold in random porous materials decreases with increased pore network connectivity.

Keywords

Effective diffusion coefficient Pore network Knudsen diffusion Percolation threshold Porous media 

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Deqiang Mu
    • 1
    • 2
  • Zhong-Sheng Liu
    • 1
  • Cheng Huang
    • 1
  • Ned Djilali
    • 3
  1. 1.NRC Institute For Fuel Cell InnovationVancouverCanada
  2. 2.Changchun University of TechnologyChangchunChina
  3. 3.Institute for Integrated Energy SystemsUniversity of VictoriaVictoriaCanada

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