Liquid water transport model does not reproduce the results of figure 3a in Chuang et al. (2020)

Calculated Damkhöler numbers are much higher than 1 at inflection points in figure 3a in Chuang et al. (2020). Further, the low-current resistance of 2 s/cm corresponds to some water saturation (~ 0.1). It is possible that at such very wet conditions the under-the-land region is already flooded. Xu et al. (2021) indeed showed that the land region is flooded earlier.

This issue could be solved by considering different behaviors for under the land and under the channel regions. And perhaps some liquid water flux to correct the Damkhöler number.

Xu, H. et al. Effects of gas diffusion layer substrates on PEFC water management: Part I. operando liquid water saturation and gas diffusion properties. J. Electrochem. Soc. 168, 074505 (2021).

Chuang, P.-Y. A. et al. The interactive effect of heat and mass transport on water condensation in the gas diffusion layer of a proton exchange membrane fuel cell. J. Power Sources 480, 229121 (2020).

Owejan, J. P., Trabold, T. A. & Mench, M. M. Oxygen transport resistance correlated to liquid water saturation in the gas diffusion layer of PEM fuel cells. Int. J. Heat Mass Transf. 71, 585–592 (2014).