Water behavior in serpentine micro-channel for proton exchange membrane fuel cell cathode

The behavior of water in the air-water flow inside a serpentine channel for a proton exchange membrane (PEM) fuel cell was investigated using the FLUENT software package. The volume-of-fluid (VOF) model was adopted to track the dynamic air-water interface. Five cases with varying initial water phase distribution corresponding to different fuel cell operating conditions were numerically simulated to obtain a better understanding of water behavior inside a serpentine micro-channel. Results show that the bend area of a serpentine flow channel has significant effects on the flow field, which in turn affects the air-water flow and water liquid distribution inside the channel or along the interior channel surfaces. The simulation results also indicate that water flooding could occur in the “after-bend” section of a micro-channel. For the case with larger amount of water in the two-phase flow, the simulation shows that the “after-bend” water distribution might block the reactant supply to reaction sites and, in some extreme situations, might block the reactant transport inside the flow channel, thus decreasing fuel cell performance.