Fuel Cell Separator Rib Taper for Low-Pressure Flow Acceleration

The gas passage is designed with locally differentiated structures: ribs with gradually-changing portions are positioned specifically in the upstream region to accelerate flow toward the power generation portion, while the downstream region maintains a larger cross-sectional area to reduce pressure drop. This local differentiation allows simultaneous optimization of flow speed at the power generation interface and pressure loss throughout the passage.

The rib structure extends in the streamwise direction (third dimension) rather than merely expanding the cross-sectional area in the transverse plane. This dimensional approach creates a gradual expansion zone that accelerates flow in the flow direction while managing pressure drop through controlled geometric transitions along the length of the gas passage.

The gas passage cross-section is segmented into distinct regions: an upstream region with ribs that have gradually-changing portions to accelerate flow, and a downstream region with a larger cross-sectional area to maintain low pressure drop. This segmentation allows the complex flow acceleration function to be localized while keeping other regions simpler.

The ribs feature gradually-changing portions with curved or inclined surfaces rather than abrupt geometric transitions. This curvature creates smooth flow acceleration and reduces turbulence, achieving flow speed enhancement while maintaining relatively simple manufacturing geometry compared to more complex three-dimensional structures.