Numerical investigation on designs and performances of multi-dimensional forced convection flow field design of proton exchange membrane fuel cell

The geometric modification of the flow field is validated as an effective measure for improving proton exchange membrane fuel cell (PEMFC) performance and reactant mass transfer ability. In this paper, a parallel flow channel with X-structure connecting two adjacent channels is established. The multi-dimensional forced convection is formed by adding the stepped shape with three connecting flow fields to increase the performance and mass transfer capacity. Six cases based on the flow field of the X shaped channels are proposed to assess the impact of different designs. The results indicate that the X-structure design improves the uniformity of oxygen distribution and drainage capacity. A stepped design with gradually increasing height improves power density and generates a large area of localized gas vertical velocity. The addition of connecting channels results in different flow behaviors at the nodes, such as slight backflow, increased flow velocity, decreased water content, and temperature rise. With a power density improvement of up to 6.9 % compared to the initial flow field, cell performance improves as the order of step height rises and the diamond structure connection channels set. The innovative flow fields are supplied as a reference for future flow field design.