Verifying Predictions of Water and Current Distributions in a Serpentine Flow Field Polymer Electrolyte Membrane Fuel Cell

A three-dimensional numerical model is used to predict the local current density and membrane conductivity inside a 10 cm 2 polymer electrolyte membrane fuel cell with a serpentine flow path. The model includes the gas diffusion layer, and it accounts for the area hidden from direct contact with the flowing gases by the current collector contacts ( i.e. , the ribs). The predictions agree with experimental data for various operating cell temperatures at a fixed inlet humidity condition. Data on closure of the water balances are presented and are also shown to be consistent with the numerical predictions of water transport by electro-osmotic drag and back diffusion. The data and the model show conditions where insufficient water lowers the conductivity of the membrane and yields low currents at a fixed voltage. Finally, predictions of the distributions of current density, water flux per proton, and membrane conductivity are presented.