Computational model of a PEM fuel cell with serpentine gas flow channels

Athree-dimensional computational fluid dynamics model of a PEM fuel cell with serpentine flowfield channels is presented in this paper. This comprehensive model accounts for the major transport phenomena in a PEM fuel cell: convective and diffusive heat and mass transfer, electrode kinetics, and potential fields. A unique feature of the model is the implementation of a voltage-to-current (VTC)algorithm that solves for the potential fields and allows for the computation of the local activation overpotential. The coupling of the local activation overpotential distribution and reactant concentration makes it possible to predict the local current density distribution more ccurately. The simulation results reveal current distribution patterns that are significantly different from those obtained in studies assuming constant surface overpotential. Whereas the predicted distributions at high load show current density maxima under the gas channel area, low load simulations exhibit local current maxima under the collector plate land areas.