Highlights:  X-ray computed tomography used to reconstruct three different types of GDL  Models of GDLs analysed using Lattice Boltzmann method  Invasion pattern and saturation of water in the GDLs is controlled by wettability  Liquid water travelled with a stable displacement under hydrophilic angles  Conversely, at hydrophobic contact angles it travelled with capillary fingering

No abstract

The impacts of image resolution on permeability simulation of gas diffusion layer using lattice Boltzmann method his item ws sumitted to voughorough niversity9s snstitutionl epository y theGn uthorF Citation: tsxxeD pF FFF @et lFAD PHIPF he impts of imge resoluE tion on permeility simultion of gs diffusion lyer using lttie foltzmnn methodF snX ondr¡ kD tFD xov¡ kD F nd f § D F @edsFAF roeedings of PHIP IQth snterntionl gonferene on edvned ftteriesD eumultors nd puel gells @efep IQAD frnoD gzeh epuliD PTEQH eugustF Additional Information:• he iletrohemil oietyD snF PHIRF ell rights reservedF ixept s provided under FF opyright lwD this work my not e reproduedD resoldD distriutedD or modified without the express permission of he iletrohemil oiety @igAF he rhivl version of this work ws pulished inX ig rnstionsD PHIRD RV @IAD ppF WQEIHIF 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.

This paper studies water transport behaviours in proton exchange membrane (PEM) fuel cell gas diffusion layers (GDLs) under the effects of a microporous layer (MPL) and some GDL structure parameters, namely thickness and pore size. Different paper GDL samples with and without MPL treatment were used in this study. The breakthrough pressure of liquid water and the amount of water retention in the GDL were measured. The results indicate that applying MPL on the GDL substrate has a greater impact on water transport behaviours in the GDL than changing the structure parameters of the GDL substrate. Compared to the GDL without MPL, the results show that applying MPL on the GDL surface considerably increases breakthrough pressure up to 4.3 times, while it greatly decreases water retention in the GDL by up to 13.7 times. For the GDL thickness, the results indicate that thicker GDL of the same structure requires up to 60% higher pressure to break through the GDL, while it can retain up to 4.8 times more water in its structure than thinner versions. Besides, the results indicate that twice-larger mean pore size GDL requires about 1.4 times lower breakthrough pressure, while it retains approximately twice more water in the GDL.