Modeling and analysis of two-phase flow maldistribution in the dead-ended anode channels for proton exchange membrane fuel cells with parallel flow fields

In the dead-end anode (DEA) mode, parallel flow fields are more prone to flooding, which can significantly impair the performance of proton exchange membrane fuel cell (PEMFC). To further explore the flooding phenomena in parallel flow fields operating in the DEA mode, the water dynamics within parallel flow fields is investigated using volume of fluid method in this study. Specifically, the effects of constant vs variable manifold widths on the gas–liquid two-phase flow are investigated, focusing on key performance indicators including water removal efficiency, gas distribution uniformity, and water coverage in the flow field. The results indicate that increasing the constant manifold width effectively reduces flooding frequency and significantly affects water dynamics. For the flow fields with a constant 7.5 mm manifold width, the water removal rate is 0.8336, the gas uniformity index is 0.7323, and the average water coverage rates at the bottom, sides, and top of the flow field are 0.034, 0.123, and 0.109, respectively. Compared to the flow fields with a constant 7.5 mm manifold width, the flow field with 1.6–7.5 mm variable manifold width has the same water removal and coverage and slightly lower gas distribution uniformity. However, the variable manifold width flow field accelerates the drainage of water from the outlet manifold, improving water removal efficiency by 18.2%. Furthermore, excessively small blind ends can cause flooding in the outlet manifold in the flow field with variable manifold width. This study provides valuable insights into the efficiency and performance improvement of PEMFCs operating in DEA mode.