A key geometric parameter for the flow uniformity in planar solid oxide fuel cell stacks

Intensive CFD calculations are performed for the flow distribution in planar solid oxide fuel cell (SOFC) stacks with different number of cells. The calculations are based on 3D models with realistic geometric and operational parameters. The effects of design parameters, such as the channel height and length, the height of the repeating cell unit and the manifold width, on the flow uniformity are examined. The CFD results demonstrate that the ratio of the outlet manifold width to the inlet manifold width (α) is a key design parameter that affects the flow uniformity. The physical origin for the effect of α on the flow distribution is discussed and a simplified 2D model with the critical details of the flow physics is developed. The 2D model provides quality result for the optimal value of α and is easy to use for the broad engineering society.