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) was examined in this paper. The 3D models of the GDL at 6 different resolutions were obtained by the x-ray computed tomography imaging technique. Each GDL image was 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 calculation time to a great extent. The results also indicate that the GDL image at the resolution of 2.72 m provides a good compromise between computation time and accuracy.