In order to achieve high fuel cell output, it is important that the reactant is evenly distributed across the active surface of the fuel cell. As part of an industrial project, an improved stack design was therefore developed in terms of the reactant distribution, pressure loss and ability to discharge condensation. The development was conducted using the FLUENT® CFD software and is based on a cascaded flow field design with parallel-connected multiple serpentine groups.
The flow field structure was optimised in an iterative process. The flow field designs were assessed in accordance with numerous parameters such as the velocity distributions in the flow field and gas diffusion layer, the reactant concentration distributions and the resulting pressure losses. In addition to the channel arrangements, we also optimised the channel and web geometries, the number and orientation of the meanders within the cascades as well as the number and orientation of the cascades in the flow field.