Effect of rib width on water and heat transfer in the gas diffusion layer

Optimizing the performance of a proton exchange membrane fuel cell (PEMFC) hinges critically on the in-depth exploration of the mechanisms governing water and heat transfer within its gas diffusion layer (GDL). The lattice Boltzmann method (LBM) serves as the cornerstone for formulating a comprehensive water and heat transfer model. This model is then employed to meticulously investigate the intricate phenomena of water and heat transport in the GDL when the rib-to-channel width ratios (R:C) are 0.5, 1, and 2, respectively. Numerical analysis reveals that an augmentation in rib width exerts a substantial inhibitory effect on the formation of water clusters and reduces water saturation within the GDL. Specifically, the case with R:C=2 exhibited the lowest water saturation of 0.432. However, this configuration simultaneously induced more heterogeneous temperature distributions, as evidenced by the maximum temperature variance of 3.239 observed at R:C=2. The results demonstrate a critical trade-off between water management effectiveness and thermal uniformity enhancement through rib width optimization in GDL design.