A numerical study on the effects of gas channel wettability in PEM fuel cells

The wettability of channel walls and gas diffusion layer has a great influence on the water management of fuel cells. In this paper, a numerical study has been carried out to examine the effect of the wall and gas diffusion layer wettability on gas channels. The investigation employed a three dimensional numerical simulation using the volume-of-fluid (VOF) method to simulate the air-water flow in a straight micro-channel representing a gas channel in a PEM fuel cell. Nine combinations of wall and GDL wettabilities were investigated. Different wettability combinations were found to give different water behaviour. For fixed wall wettability, the pattern of the analysed parameters was changing between uniform cyclic, random cyclic and continuous. In addition, it was found that changing the GDL wettability has a greater impact on the analysed parameter compared to changing the wall wettability.