The main function of the bipolar plates is to uniformly distribute the reactant gases over the electrodes. In consequence, the performance of PEMFC depends on a variety of structural and functional parameters such as the geometry of flow paths in bipolar plates, the humidity, the temperature, the velocity, the pressure and the flow of the reagents.
A three-dimensional, two-phase Computational Fluid Dynamics (CFD) model for PEMFC implemented in FLUENT has been used to analyse the effect of operating conditions such as inlet flows humidities, mass flow rates and bipolar plate geometry on fuel cell performance. The work consists of the simulation and analysis of fluid dynamic models of flow behaviour in a standard 18 parallel channels PEMFC bipolar plate and electrochemical models that simulate the phenomena that take place in the MEA.
Simulations reveal that parallel design does not allow a uniform distribution of the flow over the membrane and current density is higher at bend regions. The same analysis has been carried out in a serpentine flow path geometry in order to evaluate the gases distribution. The latter came out to be the one that distribute the reactants more uniformly and show the best performance.
To validate this results it has been manufactured two kind of material serpentine flow path bipolar plates, graphite and stainless steel ones, in order to carry out experiments on them.
Results of the simulations and test data for different bipolar plates geometries will be presented at the conference.