Computational model analysis on a bipolar plate flow field design of a PEM fuel cell

A computational fluid dynamics (CFD) analysis using commercial software Fluent have been applied to simulate and predict the complex behavior of a Proton Exchange Membrane fuel cell (PEMFC) flow field design. The numerical models are applicable for a single cell fuel cell with flow field channel and membrane electrode assembly (MEA) to simultaneously compute two-phase fluid flow, electrical current flow, species transport, pressures and temperature variations of the fuel cell. The results were compared against a published reference with good agreement. A nearly similar polarization curve was obtained at higher voltages however the Fluent model predicted that the mass concentration region were initiated earlier and reached equilibrium rapidly thus showing larger differences at lower voltage range. On the other hand the Fluent model was able to predict the liquid water activity inside the fuel cell and similar water activity were obtained at the channel exit. It was also shown that at high current density, water in liquid phase was formed over the entire operating voltages. The pressure drop was determined as well and discovered that pressure drop increases as current density increases.