Computational fluid dynamics analysis of different channel geometries in PEM fuel cell flow fields

Flow field hydrodynamics of serpentine flow channels was investigated numerically using computational fluid dynamics (CFD). The velocity profile simulated by the CFD model was evaluated with respect to experimental results from the literature. Rectangular and tapered flow channels were compared with respect to mixing and water management capabilities, and pressure drop. The CFD model was further developed to account for electrochemical reaction on the cathode side to determine which channel configuration was most effective in reactant conversion. The velocity profile differences between the channels were found to impact reactant conversion, as the rectangular channel had the highest conversion. With respect to water management, although the tapered channel was found to have a higher overall pressure drop, the rectangular channel was found to have higher shear and pressure forces acting on simulated liquid water droplets in the channel.