The impacts of image resolution on permeability simulation of gas diffusion layer using lattice Boltzmann method

The effect of image resolution on gas permeability through the x-ray reconstructed carbon paper gas diffusion layer (GDL) of a polymer electrolyte fuel cell (PEFC) is examined in this paper. The 3D models of the GDL at six different resolutions are obtained by the x-ray tomography imaging technique. Each GDL image is then characterized its gas permeability through the lattice Boltzmann (LB) numerical method. The results suggest that the image resolution has a great impact on gas permeability in both principal and off-principal flow directions. The coarser resolutions can contribute to significant changes in the resulting permeability. However, it can reduce computational time to a great extent. The results also indicate that the GDL image at the resolution of 2.72 μm provides a good compromise between computational time and accuracy.