Numerical Simulation of Condensed Water Behavior in Gas Diffusion Layers of PEFC Using the Lattice Boltzmann Method

Abstract

Numerical simulations using the lattice Boltzmann method (LBM) has been developed to elucidate the dynamic behavior of condensed water in a gas diffusion layer (GDL) of a polymer electrolyte membrane fuel cell (PEFC). Here, a LBM model of two-phase flow with equal densities was applied, because the condensed water behavior is less affected by the gas flow. The simulation results showed that the LBM applied here can simulate dynamic capillary fingering at low migration speeds of liquid water in a GDL, which is similar to the results of the LBM simulation with large density differences. Using the equal density LBM, we conducted efficient large-scale analyses to elucidate the effect of the GDL structure and wettability on the liquid water behavior inside of the GDL.