A two-dimensional numerical study of liquid water breakthrough in gas diffusion layer based on phase field method

Abstract

Liquid water transport in gas diffusion layer is essential to water management in proton exchange membrane fuel cells. Based on the Phase-field method, the Cahn-Hilliard equation and Navier-Stokes equation are used to capture two-phase interfaces in the cathode of a fuel cell. Two kinds of porous media structures, i.e. regularized porous media and randomly generated porous media based on the quartet structure generation set, are constructed to make the representative two-dimensional geometry of a gas diffusion layer. The effects of contact angle, porosity and temperature on the liquid water breakthrough process are studied, whilst the shape and breakthrough path of the liquid water are successfully captured in the simulation. By regulating the distribution of contact angles, the accumulation of liquid water in a porous medium can be alleviated and the liquid water can be quickly broken out from the gas diffusion layer. The work is helpful for material design and water management of fuel cells.