Numerical Simulation of Water Transport Performance in Tapered Multichannel for Proton Exchange Membrane Fuel Cell

Tapered channel is acknowledged as effective instrument to expedite the removal of liquid water. However, the dynamic transport mechanisms of liquid water in tapered multichannel structures, particularly the patterns of their evolution under different geometric parameters, remain unclear. To gain comprehensive understanding of the dynamic water transport process within tapered channel, a two‐phase mathematical model for tapered multichannels is developed. The study investigates the effect of tapered multichannel size parameters (channel spacing, channel outlet height, and height difference between inlet and outlet). The results indicate that when channel spacing is 1 mm, gas diffusion layer exhibits the lowest water coverage. With an increase in channel outlet height, the average drag reduction decreases, subsequently reducing the speed of water ejection. In addition, at lower outlet heights, such as 0.3 and 0.4 mm, a phenomenon refers to as “dead‐end choking” occurs, resulting in uneven gas flow distribution. Conversely, when height between the channel inlet and outlet is equal (height difference is 0 mm), the system exhibits lower pressure drop loss and improves water distribution performance. Overall, tapered multichannel demonstrates effective water removal and uniform gas distribution when channel spacing is 1 mm, outlet height ranges from 0.4 to 0.5 mm, and the height difference is within 0 to 0.1 mm. This study provides the first quantitative design framework for the geometric parameters of tapered multichannel structures, laying a solid theoretical foundation for optimizing water management in PEMFCs.