Multiphase, three-dimensional PEM fuel cell numerical model with a variable cross-sectional area flow channel

Purpose This paper aims to investigate the impact of three different flow channel cross sections on the performance of the fuel cell. Design/methodology/approach A comprehensive three-dimensional polymer electrolyte membrane fuel cell model has been developed, and a set of conservation equations has been solved. The flow is assumed to be steady, fully developed, laminar and isothermal. The investigated cross sections are the commonly used square cross section, the increasingly used trapezoidal cross section and a novel hybrid configuration where the cross section is square at the inlet and trapezoidal at the outlet. Findings The results show that a slight gain is obtained when using the hybrid configuration and this is because of increased velocity, which improves the supply of the reactant gases to the catalyst layers (CLs) and removes heat and excess water more effectively compared to other configurations. Further, the reduction of the outlet height of the hybrid configuration leads to even better fuel cell performance and this is again because of increased velocity in the flow channel. Research limitations/implications The data generated in this study will be highly valuable to engineers interested in studying the effect of fluid cross -sectional shape on fuel cell performance. Originality/value This study proposes a novel flow field with a variable cross section. This design can supply a higher amount of reactant gases to the CLs, dissipates heat and remove excess water more effectively.