Visualization experiments and pore network simulations for invasion-percolation transport of a non-wetting fluid through multiple porous layers

► A similarity model experiment was developed for liquid water transport in multiple porous layers of PEMFCs. ► Capillary fingering was reduced with an intermediate layer inserted between a fine and a coarse layer. ► A thicker intermediate layer led to more significant reduction of non-wetting fluid saturation. ► A multi-layer pore network model was developed to reproduce the similarity model experiment. ► Numerical results showed relatively good agreement with experimental results, qualitatively as well as quantitatively.