Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
Transient performance of a polymer electrolyte membrane (PEM) fuel cell in terms of the time-dependent current density profile that responds to the varying cell potential is of critical importance for an automotive PEM fuel cell. A step change in cell potential is applied to the cell terminals to simulate a sudden change in load demand due to an engine startup or very high acceleration. The transient responses of the three most commonly used flow-fields, namely, parallel, single-serpentine, and interdigitated designs in terms of the magnitude of current overshoot and time taken to adjust to the new equilibrium state are compared. The results suggest the serpentine flow-field outperforms its two counterparts as it balances the satisfactory transient performance with an expense of acceptable pressure drop across the cell and hence it is the most appropriate design to be used in automotive PEM fuel cells.