Impact of manifold design on flow distribution and cell performance in SOFC

ABSTRACT Solid oxide fuel cells (SOFCs) are a promising next-generation energy technology, yet flow maldistribution remains a key obstacle to their efficient and stable operation. To address the cathode flow field inhomogeneity, this study systematically investigates four manifold configurations (Cases 1–4) using numerical simulations to evaluate their effects on flow distribution and cell performance. The results demonstrate that conventional manifold designs (Cases 1) exhibit significant vortex formation and flow separation at sub-channel inlets due to gas inertial effects, leading to non-uniform flow and oxygen distribution. In contrast, the introduction of square-column flow disruptors (Case 2) and trapezoidal connecting tubes (Case 3) significantly improves flow uniformity, reducing the flow distribution non-uniformity coefficient to 28.07% and 20.03%, respectively. The composite structure (Case 4), which combines the advantages of both optimized designs, not only further reduces the flow non-uniformity coefficient to 19.16% but also decreases the system pressure drop by 12.59%. Notably, the composite manifold (Case 4) demonstrates superior performance in multiple aspects: enhanced electrochemical performance (average current density increased to 0.89159 A/cm2), improved temperature uniformity (maximum temperature difference in the electrolyte layer reduced by 18.04%), and reduced thermal stress (maximum thermal stress decreased by 8.63%). The performance advantage of Case 4 remains robust under both channel scaling (from 13 to 17 channels) and varying inlet flow rates (800–1100 SCCM), confirming its strong adaptability and reliability across different operating and structural conditions. This study provides innovative design strategies for SOFC manifolds, offering significant potential for improving cell efficiency, lifespan, and operational safety.