A Streamline Dot Flow Field Design for Proton Exchange Membrane Fuel Cell

Abstract

Flow field optimization plays a vital role in improving the output performance of proton exchange membrane fuel cells (PEMFCs), especially at high current density. A streamline dot flow field is proposed in this study to enhance the mass transfer of reactant gas and compared it with parallel, rectangular dot, and rhombic dot flow fields. The influence of the tail length of streamline dot block on the performance of fuel cells is further analyzed. The results show that the uniform distributions of pressure and oxygen molar fraction are significantly increased in dot flow fields compared with parallel flow field. In dot flow fields, vortices produced behind the dot blocks could increase the flow resistance and pressure drop. Among six models, the dot flow field with 2 mm tail has the most uniform current density distribution at PEM-CL cross section, and its index of uniformity current density (IUCD) is the smallest with the value of 0.012991. And the parallel flow field model has the largest value of IUCD. Compared with parallel flow field, the current density of streamline dot flow field model with 2 mm tail increased by 4.9%.