Analysis of fluid flow behaviour in different proton exchange membrane fuel cell flow field configurations

The performance of a proton exchange membrane fuel cell (PEMFC) stack is largely affected by the bipolar plate design. Uniform gas distribution throughout the active area with effective mass transport is critical to avoiding activation, concentration and ohmic losses that can reduce the overall stack performance. In this study, three inlet/outlet turning angles (90, 135 and 180 degrees) were first simulated with a conventional parallel (CP) flow field. It was found that the 135 degrees inlet/outlet angle showed the most optimised fluid distribution in the flow field. Thus, improving fluid uniformity up to 6% and reducing pressure drop up to 36%. This turning angle was then simulated in three different flow fields (modified serpentine [MS], modified fishbone [MF] and Tesla valve [TV]). MF generated the lowest pressure drop value of 80.11 Pa, but flow channelling was apparent in the fluid channels. The pressure drop in MS was 43% higher than in TV. Furthermore, the continuous fluid flow mechanism of the TV design generated up to two times higher uniformity level than MS. Hence, a TV flow field with a 135 degrees inlet/outlet angle evidently demonstrated uniform fluid distribution, which can significantly enhance the multi-phase fluid dynamics in a PEMFC.