Fuel Pressure Distribution as a Criterion for the Bipolar Plate Geometry Optimization in PEM Fuel Cells, Modeling and Experiment

In this study the pressure distribution homogeneity on the catalytic surface is found to provide a simple and reliable fuel flow parameter that can be used to optimize the bipolar plate geometry and the PEM fuel cell performance. Finite element commercial ANSYS software was used to determine the fuel velocity, pressure and mass distribution on eight different bipolar plate geometries. These geometries were also fabricated and characterized experimentally in order to establish a correlation between the power densities with the fuel flow parameters obtained from the simulations. The results show that a highly uniform pressure distribution of the fuel in the bipolar plate is necessary to obtain higher power densities. Inversely, non- homogeneous pressure distributions lead to lower power densities. Additionally, the measured power density increases when the geometry dependent effective catalytic surface area increases. These results are interesting since they provide an optimization methodology for PEM fuel cells that simplifies and reduces computing requirements, experimentation and manufacturing time.